Eyjafjallajökull flight cancellations: How the right decision is being made to look wrong

Erik, very well said! You should get on your soapbox a bit more regularly.

To paraphrase what was once said over at Effect Measure regarding Public Health measures: if they work nothing bad happens and people then say they were unnecessary to begin with. Think of Ibsen's "Enemy of the People". Or a more pop reference - "Jaws".

Many people are narcissistic and think only in terms of money and convenience, their own that is. Although its popular to say that this attitude is American, this case illustrates that its a universal human trait. And despite what these folks always say about over-regulation and it not being the job of government to decide risk or save you, they are always the loudest to complain when something happens and emand that someone save them. They wrap it in idealogy, but its really nothing more than narcissism.

Please use your soapbox more often! The truth is no one died so the ban did its job. If the airlines put money ahead of safety the next time, and there is an accident I think we should provide the pike poles.

Those NASA image links doesn´t work Erik.

@Mattias - Hmm, they seem to work for me. They are a little slow today, but I got them to load.

I don't agree! Your assessment is too simple.

Huge parts of EU airspace have been closed without reason for a too long period of time!

For a correct and balanced view of the entire problematic

please read this blog post here:
http://eureferendum.blogspot.com/2010/04/hook-line-and-sinker.html

and this comment in response to a posting at http://wattsupwiththat.com/2010/04/21/airlines-blame-flawed-computer-mo…

Richard North (13:41:42) :

"Echoing Steve and some others, there is nothing inherently wrong about using computer models for forecasting ash dispersion. Over the short-term, these have a good track record â the parameters being modelled are limited and, unlike long-term climate models, are falsifiable. Thus, there have been several upgrades, based on real data from actual eruptions, which makes the model a fairly useful tool.

However, from what I can ascertain, the predictions degrade with distance and time, and after about three days there are considerable uncertainties, both as to location and to particle density. Thus, it is imperative to supplement the modelling with physical measurements â using ground sensors and airborne sampling.

This is where the UK (and the rest of Europe) seems to have been caught out. There is a serious shortage of suitably equipped and available aircraft for ash sampling, which meant that the first sampling flight by a suitable research aircraft (i.e., other than the ânoddyâ Do 228) was not carried out until Monday in UK airspace. It is no coincidence that, by Tuesday, the ban was lifted.

It seems to me, therefore, that the essential flaw is that the ICAO contingency plan puts too much emphasis on modelling, and does not insist on confirmation from physical measurement. I have my suspicions that this omission is due to a reluctance to commit member states to additional monitoring costs".

I have explored these issues here:

http://eureferendum.blogspot.com/2010/04/struggling.html

Have there been any recent IF pics of the top of the glacier and or the craters?

Erik,
I just posted a comment that did no appear!

Would you please be so kind and publish it!

Thanks in advance.

You are right. It must have been temporary because they work now. :)

To answer a question in the other tread. There is a good chance that the heat that was always present in the crater has increased following this eruption, and therefore make more melt water in the process.

At current time I fear a new fissure opening in the cater, like the one we did see on Fimmvörðuháls eruption. But the current crater and eruption pathway have been getting a lot more closed up according to observation over the past few days. If that happens, we are going to see a new big ash cloud, and maybe new closure of Europe air space.

R. de Haan - I appreciate your input, but I fear a lot of this falls into the axiom that "handsight is 20/20". Decisions were made on the best available information - and Europe just wasn't ready for abundant sampling - so the logical conclusion would be to err on the side of caution. I tend to think that the Tuesday opening had more to do with the change of eruptive style than sampling, but we can't get in their heads. Now, hopefully, this means that the right equipment can be put into place for future events.

further fuel for the soap box discussion -
http://news.bbc.co.uk/1/hi/uk/8637978.stm

Seems it is right to be cautious with high performance jets but not with the lives of the public! Anyone know of any data reported from the commercial companies on ash deposits?

The weather has been bad all day but seems to be clearing up. Looks like our heli pilot will take us up there soon, hopefully to land on the crater rim. Anything you folks want me to look for or photograph if/when I get up?

@Jon What are the red lines on the helicorder? Sorry but I am just a beginner...

Another problem is a fundamental distrust and misunderstanding of science. It worries me when the airline's argue that there is a "lack of empirical data" when the ash cloud is staring them in the face. Or when politicians argue that climate change is not real because there was a big snow storm in DC.

As a modeler, I am fascinated that numerics can replicate nature. And to be fair, there is human imagination and interpretation involved in any model. But models are not just fancy graphics and wild interpretations like we see in the movies. Just because these people don't understand calculus doesn't mean that the dx of an accelerating car (or ash cloud) is not going to follow dt in a predictable way. And that prediction, if we have proper tools, is going to be darn close to reality.

UK military has suspended there military flights because of ash.

http://www.google.com/hostednews/ap/article/ALeqM5jh7lQ-qBxQMPzPd3Iap7_…

@renee, This is a automatic warning system that my software has in the case there is a big earthquake. This warning can however be triggered by a noise sometimes. In this case, this is noise but not earthquake.

Hi Erik,
As an airline pilot, HF Masters student, and former accident investigator for my airline pilot's union a whole-heartedly agree with your points. In fact I am supposed to go out today to the Netherlands, so it will be interesting to see conditions first hand in the area.
A few days ago I wrote an email to my Union "asking" how are the regulatory agencies will be able to effectively (thus constantly and and scientifically) monitor conditions (once determined by engine and aircraft munufacturers), something that yet has not been made public. The models, which leave some questions unanswered, might work under some assumptions; but is a gamble of economics which might be used once again to scapegoat safety, science and good judgment for profits in a short term.
Rick

New to this blog, it's awesome! The grounding of the European air flights was a good idea. Over the coming days and weeks, I think the airlines who fly through ash contaminated air will be find themselves making many engine repairs.

I just hope that there are no unfortunate accidents, abrasive ash material, even in small amounts is dangerous, period. I know that airlines are upset the have lost $1.7 billion USD, but what is the value places on people, "their precious cargo". One unfortunate mishap can cause the lives of their passengers, will cost millions and lead to a real problem.

While looking at this cam http://www.mulakot.net/myndavelar.html (3rd picture down) I see in the distance on the left another possible plume? At first look it appears to be clouds, but is it possible this is another volcano plume?

@James, do you think that is possible to go up there? The cloud is mean looking at the moment, it is getting worse as the time passes.

Very nice plume on both Mulakot cam and Hovo cam.

@Jon:

It's definitely better now than it seemed a little while ago. The pilots are saying they can fly but people may not see anything if they opt for a fly-around. Since we will be landing on the rim I'd say we have a better chance of seeing stuff.

Seems they think it is at least safe to fly. The forecast is for the weather to clear up this afternoon and they're hanging around into the evening, so I'm hopeful.

@R. de Haan #6 The bit I liked was where he said..."considerable uncertainties".

So would it also be fair to say, because of the unknown levels of ash, that there could have been "considerable uncertainties" about there not being an accdent?

Without knowing where the ash and levels were, wouldn't it be better to send the planes with members of the public onboard to find out?

This has more to do with the media smelling a bone to play with....

People should be clear on why the ban was lifted. After examining the engines of aircraft that had taken test flights through the affected areas, and in consultation with the engines' manufacturers, the Civil Aviation Authority increased the threshold amount of ash in the air above which it was unsafe to fly from 'any at all' to 0.002 grams per cubic metre (see this New Scientist report).

This change meant that large areas of European airspace automatically went from being classified as 'unsafe' to 'safe'. It was nothing to do with reassessing model predictions. According to the UK Met Office, actual measurements on test flights largely confirmed their modelling of the ash cloud dispersion.

All this means is that ash at those concentrations will not damage jet engines enough in the course of a single flight to cause dangerous mechanical problems, but I'd suspect that it will increase cumulative damage over time. Hopefully the airlines bear this in mind!

Here is a picture of the water that was once in front of GÃgjujökull before the eruption. This lake is now gone.

http://picasaweb.google.com/lh/photo/E75aSZBHO3_Kg7bWocmmPA

Now we know why the airlines claim to have wracked up enormous losses during the prolonged flight restriction period: IATA made them pay for food and hotel costs for stranded passengers.

Too many flight control centers and jurisdictions with criscrossing flightpaths, especially when complex vertical column mixing and crosswind conditions cause rapidly varying ash flux conditions at various altitudes.

Learning-curve chitchat with numerous experts at EuroControl is planned - we heartily hope participants will include INGV geologists for their experience and insight in ash forecasting and civil impact planning.

As a former Professional Pilot, and dealt with the aftermath
of St.Helens and as a Commuter Airline Pilot,the aftermath
of a mechanical-human failure crash-as in the Chief Pilot
ok'ing an unsafe aircraft-as written up by the previous crew(s) for flight,I was one member of those. Caution is the best way to save lives. From my own experience with St.Helens,
Ash clouds can be inconsistent-as we have seen. An Airbus
or Boeing full of people over the North Atlantic with dual
engine failure-would have even more dire consequences than
inconvenience. Good call,Erik...

Plume is darkening on the Poro cam

@ Passerby (26): "IATA made them pay for food and hotel costs for stranded passengers."
Actually, it's the EU law that airlines are obliged to pay for food and accomodation for passengers whose flights are cancelled or significantly delayed. So nobody made them do it, it's a binding regulation.

Ryanair is one of the companies that does not want to pay for this. They say they will only reimburse expenses up to the original price that you paid for the ticket - they say if you paid 1EUR, there is no way they can afford to give you 500EUR for a week in hotel. According to Irish news though (www.rte.ie), it's likely they will be brought to criminal court in Ireland if they don't follow the EU law.

A dumb question for the geologists...but looking at Jon's pic above of the glacier before with the lake in front. Why is the glacier actually at that spot?
I look and it is like a big split right down the side there. Also I am wondering, if that is an old vent under the glacier, as the rock towards the bottom looks different.

Regarding the planes, well I think sadly alot of it is becoming "Dont baffle me with science man".

And although humans in an ideal world are supposed to be altruist etc. etc. The reality is that there will be people calculating right now things like....well if we only lose 1 plane a week and that costs 500million, but the losses of not flying are 1 billion per week....so long as < 2 crash per week - we are still ok.

Sounds terrible but that is how the world is. That is essentially what actuaries are paid to figure out.

Many thanks to Dr. Klemetti and all for a great blog- with two geologists in the family, some first-hand familiarity with Iceland, (including' Solfaxi' to East Coast Greenland in 1956 and other years,) and friends in the Reykjavik area, this is for me a most interesting, at times addictive, and always informative top-of-the-list 'bookmark.'

A better way to put it might be - is the glacier there because of the underlying geology, or has the glacier caused the topography?

Hmmm at least I know what I am trying to say...

Re #15. Mariek, I agree. What their claim "a lack of empirical data" tells us is that they are people with very little understanding of problems that contain more than one, simple variable and to whom science is and should be a simple question of "black or white". Scary when you think about it...

They complained about Wall Street having too many regulations....no one could make any profits....the risks were manageable. Then they got rid of most the regulations....people made money and for awhile nothing bad happened....but only for awhile;)

Airline safety regulations....just like Wall Street regulations are there for a reason....Pardon my wording but...."A Greedy Bastard"....will always send you over the cliff for a profit. Instead of wasting time complaining and threatening to sue....they need to be figuring out a Plan B....because sooner or later one will be needed.

ab actu ad posse valet illatio

@James, If you do manage to fly today, Stay safe!!

About ~30 minuets ago the cloud started to grow, and to get darker. This does not look good in my opinion.

Does this look like a new crater? It seems to be more to the right then before

It's Y2K again: people spent huge amounts of time, effort, and money (mostly) preventing problems, and for their pains, they got told that there clearly hadn't been anything to worry about.

How many people would sign waivers, that in case of injury or death from an air accident during this EU-declared volcanic alert, they and their estates could not sue the government or the airline for damages?

Whether or not such a waiver would hold up, it might give pause to some of the people who are sure it's safe, or sure it's worth the risk. My life should be worth more to me than a hundred thousand or a million euros paid to someone elseâit's not like taking a dangerous job for which you collect a monthly paycheckâbut somehow, people make odd tradeoffs. But people are strange, and money can make things feel realer.

Or, turn it around: any airline that chooses to fly during such conditions indemnifies the passengers and/or their estates for 10 million euros each in case of any crash. If they want to blame the government that they didn't fly, and demand compensation (funny how capitalism flies out the window when corporations lose money), they should be prepared to take full responsibility for doing so.

Impossible to tell due to clouds at the moment. But there are indicators that there currently two plumes coming from the active area. But we will have to wait and see what is going on, if the cloud clears.

@32 Scott.
Topography both influences the formation of glaciers and glaciers shape the topography.
Glaciers form when there there is always some snow remaining after the summer melting and it accumulates over many years. To do this you need the right combination of temperature and precipitation, which are found at high elevations and latitudes. Topography plays a role then in the creation of high elevations, but note that the conditions are right for glacier formation at low elevations in the Arctic and Antarctic.

Glacial ice flows downhill away from the zone of accumulation, overrunning and eroding the landscape.

Still a question about blalancing between Risk A and Risk B. The closing down of european airspace has probably caused some deaths, but nobody will repoort them : organs for grafts have not arrived, medicines were not flown in, and half of french cardiologists were stranded in Tel-Aviv. The flower and fruit producer could not export their products from Africa and South America - and this may well cause much more than inconvenience. If it had been completely obvious that flight was too dangerous, there would be no debate whatsoever. The fact is that we did not have even probabilistic evaluations of the risks. So, the european authorities chose the unreported deaths against the very publicized deaths caused by a plane crash.

It makes lots of sense to choose aviation safety and its image against everything else - but it would be better to give all the information.

@39 Jon, which url are you looking at and seeing 2 plumes?

I am on the side of "Better to be safe than sorry".
I think the right decision was taken to close the airspace, regardless of inconvenience/money. I was rather be inconvenienced than dead.

Erik, the one thing you have to remember when reading these news stories is that their viewpoints are established by journalists--who mostly tend towards science illiteracy, if not disinterest, and love nothing better than writing about confrontation and blaming.

I remember when Mount St. Helens erupted in 1980. The press was all over the angle that the government didn't do enough to keep people away from the mountain. They almost completely ignored the 'hard-to-predict natural catastrophe' aspect, in favor of scapegoating someone, ANYONE.

A great deal of the press coverage of the Iceland eruption has revolved around only a few subjects: 1) How many tourists were flocking to see the eruption? 2) How many passengers were stranded/ inconvenienced? 3) How many zeroes after the dollar sign are involved? 4) Which passengers in the political and entertainment fields were kept away from conferences/funerals/premieres/press junkets/concerts? 5) What if Katla blows up (preferably in a super-eruption)?

Most other considerations were pretty much ignored. Worldwide cargo disruption and its consequences? Boring. We wanna know where the "Iron Man 2" premiere will be held, right? And now the favorite angle of the press is "Were PEOPLE responsible for this volcanic fiasco?" And of course, if any planeloads of people HAD gone down, the media with one voice would've bemoaned that PEOPLE in government didn't do enough to prevent it.

No wonder an awful lot of news audience members were under the impression there must be something PEOPLE can do to stem the eruption. Aargh!

just a stupid not related question but will give me the oportunity to follow on

on wich GMT is this site ?

@Dan, I was looking at the Vodafone web cam. But due to cloud I am far from sure what I did see, or not.

On the Ãórólfsfell webcam you can see occasionally the plume which indeed appears bigger and denser, and to the left a dense dark pall of ash like we haven't seen since a couple days; Jón may be very right in expecting an increase in the activity.

Have you all read this report?

http://www.raunvis.hi.is/~mtg/nemritg/BV-MS_2009.pdf

@45 this site is on The US east coast I believe, which I think is GMT -4 at this time.

@46 Thank you Jon. You are in Iceland and seeing it live and not the picasa site?

How Alaska Air does it (WSJ):

http://online.wsj.com/article/SB100014240527487041338045751981837579309…

Snipit:

A collaboration of aviation and weather experts created computer models that predict the trajectory for volcanic ash in Alaska or elsewhere in the Pacific Northwest. Whenever there's an eruption, the airline scrambles off-duty pilots in empty airplanesâsome in Alaska Airlines's Boeings and others in smaller private planesâto take temperature and wind measurements at various altitudes. The data help validate satellite projections and computer forecasts.
"The more data you have, the more surgical you can be," said Capt. Williams.

On the flip side of this ,and it is getting some press, the Finnish airforce is showing pictures of damage to an F-18 that flew through the ash. This should act to shut up some of the airlines. (translation quality may vary, I copy/pasted)

Text of: âTuhkahiukkasista konkreettista vaaraa lentoturvallisuudelle Suomen ilmatilassaâ

The Air Force has investigated on the damages that occurred on Thursday and Friday on the F-18 of the Lapland squadron. The aircraft took off on Thursday morning for an air exercise in the North-Finland airspace. Then the airspace was still fully open.

After they had landed, the aircraft were checked and volcanic slag was found in the air inlets of the engines. Both engines of one of the Hornet were investigated with a fibre optic camera. On the pictures one could observe, that even with a short flight that smoke particles could cause significant damages to the aircraft engines.

Pictures of engines have proved that the particles accumulated in the combustion chamber, where they melted approximately at a temperature of 1000°. Melting ashes accumulate in the cooler engine exhaust and provoke overheating of some parts and weaken some metal. Weakened metal generates for the rotating parts of the engine the danger of cracks. In extreme cases some parts could break and destroy the engine.

The Hornets exposed to the ashes are scrutinized carefully. In any case some engine parts will be replaced and running tests will be conducted at he Patria workshops. Damages parts are to be taken down as far as deemed necessary in thee engines, in which we would observe anomalies because of the smoke particles. This will apply for instance if particles are detected in the exhaust.

Operational flights will be operated as usual.

Despite the particle cloud, an Air Force Hawk training jet, equipped with a pod conceived to take samples, is ready the period the airspace will remain closed. The aircraft will fly anywhere on request of the civilian authorities.

On the basis of the information gathered by the aircraft, we will be able to determine how much smoke particles are in the air. The results will be forwarded to the civilian authorities, which will make out of the results of the gathered knowledge their decision as for the use of the Finnish airspace refers.

The reconnaissance aircraft will fly at a defined altitude and will gather in a filter the particles it will cross. After the landing of the aircraft, the samples are sent to the National Defence Research Centre in Lakiala. To get the results we need about two hours, which are then sent to Finavia. When deemed necessary pilots will report in real time their direct observations. The observation aircraft is operated by people from Kauhava Air Force school.

Despite the smoke cloud the Air Force operates as usual the operational flights, like activities linked to the preservation of the sovereignty of our area.

Ther is a much darker plume to the left of the main cloud in this cam: http://www.mulakot.net/myndavelar.html

Shadow?

11 @ Erik,
Thanks for your response Erik.
The problem was that the ban took too long!
Those responsible could not be contacted and a first meeting was planned for Monday!

In the mean time, Saturday and Sunday, we have been looking at blue skies over major parts of Europe.
KLM and Lufthansa made their first ferries on Saturday and further ferry flights on Sunday!
This experience together with frantic attempt from the Dutch Traffic Minister to contact all the responsible EU officials finally lead to the lifting of the ban.
I am sure this won't happen a second time!

Also read: What a difference a day makes!
http://eureferendum.blogspot.com/2010/04/what-difference-day-makes.html

@Dan, Yes I live in Iceland. So I can view the Vodafone web page.

The plume is not mixture of white and darker material, something that has not been seen for few days as mentioned above.

@Vicky [38]

"funny how capitalism flies out the window when corporations lose money"

No, capitalism doesn't fly out the window. The freeloaders (whether a bum or a company) eagerly seek the easy route. If they can get some one else to cover their bet, they do it. Strictly hold to the capitalist principles and the problems will take care of themselves through an elimination of the weak, and those who take unnecessarily risk.

You make what you earn, and you keep what you kill. It's a bit draconian, but with laws to prevent over exploitation of advantages (monopolies) and the violation of morals (rape, murder, fraud etc.), it generates a rather sane and pleasant social order.

Where the problem arises is when this idea is corrupted by the implementation of safety nets which are then extended to buy votes and political advantages. The two don't mix well.

On one hand we have airlines, who are notorious for holding the flying populace with disdain and treating them no better than livestock, bleating about lost revenue since they can't ferry the produce around, nickel and dimeing us at every step. And on the other, we have an overbearing bureaucracy that can't make make an accurate model to save it's ... well, you know.

Since the reaction of airliner equipment is proven to be "bad" when it encounters ash... erring on the side of caution makes sense. So, despite the dodgyness of the model, it's the best guess.

The "Ãtsýni frá Ãórólfsfelli" web-cam shows our Icelandic Volcano spewing out a decent steam/ash plume this afternoon. Clouds have cleared somewhat from earlier today.

Aside the plume darkness, from the Ãórólfsfelli webcam it appears there is a brownish haze next to the plume.

Thanks for this statement. Reading the press or looking TV you can't believe, how nationalistic the medias all over Europe were. VAAC London was declared as "this british institute". Austrian, German or French medias declared, that no danger exsitied, if agencies of their own country would be responsible for the forecast. Real rediculous conclusions.

Excuse faults

Walter

Thanks for this statement. Reading the press or looking TV you can't believe, how nationalistic the medias all over Europe were. VAAC London was declared as "this british institute". Austrian, German or French medias declared, that no danger exsitied, if agencies of their own country would be responsible for the forecast. Real rediculous conclusions.

Excuse faults

Walter

@Boris looking at the poro cam my first impression was like yours.
a grey and a white plume.
however if you look longer at the dark side and a piece sticks out far enough then it turns white.
could it be that the plume is so dense that sunlight gets blocked and turns the backside grey?
becuase looking at the Mulakot cam it looks like a full white plume.

This is how bad it is in the US. When the President makes a radio address, the opposition always responds. One of the first responses by the Republicans was from a new Governor who attacked the President's budget for having lots of waste and unnecessary things. Politics as usual.

However the item that this Governor chose to attack was money for a volcano early warning system in the Pacific Northwest. How incredibly silly to be wasting money on volcano warning systems! He even made a little joke of it, something like "we need to be more worried about a volcano of spending." Ha! Ha!

http://www.cnn.com/2009/POLITICS/02/25/jindal.volcanoes/

"Jindal singled out a $140 million appropriation for the U.S. Geological Survey as an example of questionable government spending during the GOP response to President Obama's address to Congress Tuesday night. "

I bet that there are people in Europe who would be happy to have spent a bit more on volcano warning and monitoring systems right now...

I'm sure that the famlies of the people who died in the Helens eruptions were in stitches.

To add insult to irony, the Governor in question was from Louisiana, a state that has receieved billions in (belated) federal aid to deal with their natural disasters. Somehow Hurricanes are real, but Volcanoes are not.

Looks like the RAF has run into problems. Ash was found in one of the engines of one of their Typhoon fighter-bombers after a training flight from RAF Conningsby in Lincolnshire. Said training flights have now been suspended.

@Boris (#47) Yesterday at 10.44 GMT, there was a black plume that extended all the way down the flank WSW from the vent (I have a Mila Hvolsvelli screenshot of it). True, the height at the vent was no more than a few hundred metres, but as it travelled down, it gained in altitude until it was ~500m high or so.

You can see a great deal of dark ash on the Vala cam but you need to expand it to full screen

Jon, I was fortunate enough to visit Iceland in May 2001. In KeflavÃk I found a good restaurant by watching for a while to see who entered. :) When I saw it was mostly local people I decided to eat there. LOL I had enought time to make the drive to ReykjavÃk also and of course visit the Blue Lagoon. I really hope to be able to visit again with my wife. She has seen my pictures and would love to visit. I consider myself one of the lucky few that have been able to experience your beautiful country and it's wonderful people.

Wow it does look like there is alot of ash now. On the Vala cam almsot the whole screen is covered by ash excpet for the far right where there is still blue skies. I guess the volcano was just taking a break.

Check out the Ãórólfsfelli cam on mila.is - there's a guy in front watching the eruption!

@66: the plume height from the Mulakot webcam hasn't changed much though (aside the fact that there it looks very white, steam-charged).

@44 mjkbk
The St. Helens story is actually a great example of how public/press attitudes shift and scientists and emergency management are blame for first doing too much and the doing too little.
Prior to the big May 18th eruption there was considerable pressure on officials to lift restrictions around the mountain coupled with popular sentiment that the scientists had overreacted and that the eruption would be trivial. Then after May 18th attitudes flipped.
Erik, this could be a possible angle to explore on the upcoming MSH anniversary.

EKoh is right about St. Helens. I live in Washington state, and followed the eruption very closely. The day before the eruption, as pressure mounted on government officials to life the restrictions, they did let a group of homeowners back into the area to check on their property. There was a caravan of of 20 property owners, with national gaurd helicopters posed to rescue them just in case (they would not have had time if it had blown then). They were accompanied by reporters and photographers. There was, in fact, another caravan planned for May 18th, but fortunately for them, the mountain erupted early in the morning before they would have been up there.

There's a distinct possibility both KeflavÃk airport and ReykjavÃk Airport will be closed tomorrow.

here's a good article about the flight cancellations and the different agencies involved: http://www.bloomberg.com/apps/news?pid=20601209&sid=axtzV9LXrRzQ

Hm, the guy in front didn't stick around very long - he left by the I got my last message posted. Heh.

Anyways, here's a timelapse of Eyjaf from yesterday: http://www.youtube.com/watch?v=GzuXj1tkvdQ

Seems winds will be mostly from the east for the next five days or so.

So the European airspace will probably be pristine before long.

According to RÃV the steam plume rose to 6 km today and the ash plume to almost 5 km.

Hey who said that all of Iceland is below the Arctic Circle!

I had forgotten about Akureyri and it's airport :-)

Regret never having gotten there. Sigh.

Erik, great blog entry, I think you are spot on. Everyone except the Icelandic people/authorities and the volcanologists appear to have been caught totally unprepared. Even with my very scant geological knowledge I was aware that eruptions like this have happened and will happen again in Europe. I'm just glad this has been a comparatively small eruption so far, giving people the chance of a wake up call to do some basic preparations for a larger event. I would go even further to say surely it is the airlines responsibility to have mitigation plans for their own operating risks. They are after all the ones standing to lose the money. Seriously airlines... don't bash the MET office model till you have one that's better or up-fit some of your own planes with monitoring equipment. As far as I have seen the actual scientific test flights, although limited by hardware availability, have all pretty much proved the model accurate. As for a "100% safe" concentration of this type of high silica content ash to fly through, is 10-16 ppm3? Any concentration will cause extra wear, especially newer turbine blades that have been CFD optimised to use as little cooling air as possible for fuel efficiency/profit. I'm thinking in flight particulate monitoring with flight time/service intervals auto-adjusted by an empirically derived factor could be used. I Just hope the boroscope inspections and turbine pyrometers are up to it for now. Time will tell.

Yes the behavior of the plume is definitely interesting. So the dark pall to the left in some of the webcam views seems to indicate we have this peculiar segregation of a dense ash plume trailing at low altitude, or even trailing on the ground, as a few days ago, and the lighter vapor rises higher up ...

I wholeheartedly agree with everything stated at the opening of this thread by Erik. I could not have said it better myself and I am so pleased I am not the only one thinking like that.

Well done. Endless Praise heading your way.

When it comes to the closed air space, I think some people are forgetting the weight of responsibility. It's esay to say that the wrong decisions were made, if no one ever will hold you responsible for your opinion. On the other hand, people who made the decision would be personally resposible if a plane went down, and they would have to live with that.

Thanks for a great blog, and thanks to all of you who contribute with valuable comments! I've been lurking here for some time.

The airlines are going to have to face some interesting economics if flying in these conditions results in increased wear out/maintenance/inspections. Already there have been cases where engines have had to be torn down for inspection. Not many, but it doesn't take many to make a route or a particular location unprofitable.

If they are going to fly in those conditions, expect fares to rise dramatically. Now whether or not they increase fares only in Europe or globally to compensate depends on the airline. Regional carriers that do not fly routes outside of the area are going to have the hardest time as they can not raise fares on flights elsewhere to subsidize the higher maintenance on the European routes.

Some carriers might also choose to abandon certain routes anyway if the costs are too high. A carrier flying only a few flights into the area might determine it isn't worth the added expense and drop the route.

In any case, it is going to be interesting to see how it plays out. I suspect we are all going to be paying higher fares to compensate for the additional maintenance.

Great blog, great soapbox.

Two thoughts: first, if the airspace had opened while the ash lingered over Europe, I suspect the airline executives who would have flown aircraft would almost certainly have prepared a variant of the memo Ike wrote on the eve of D-Day and kept in his pocket in case the invasion failed: we only flew because the EU let us, and we thought they wouldn't have let us fly if it wasn't safe. Their fault!

Second, in the future there should be a protocol for an extended test flight before opening airspace. It should require that the aircraft be filled with the airline executives who would authorize general passenger flights.

Just for the fun of it, I'm posting a link to a picture of mine from Iceland. This picture begs the question - "You decided to build your house there why?" :)
http://www.flickr.com/photos/8388935@N04/4523688422/sizes/o/

Looked like it was clearing, but now it's not. We're not going. What a shame.

We're going to try again next week when the weather improves again, so we'll see...

US this morning our non-profit public broadcasting radio had a story on the efficiency of the SPEED TRAINS in France. Apparently it is possible to get around Europe via train with these speed trains which some air passengers say they will do from now on. Apparently, less of a wait at train stations than airports and many found the experience most enjoyable.

It can be difficult to tell ash from steam, because of the light being blocked by the plume. If you just look at the Old Faithful web cam right now (http://www.nps.gov/archive/yell/OldFaithfulcam.htm) you will see how dark it looks. Definitly, not ash.

Two Georges :) Hmm.

@R. de Haan

I don't agree that the ban was too long, in my opinion, it was too short. Just because you're seeing clear skies doesn't mean there isn't ash. I'm a pilot and will not try and discuss specifics of the eruption as that is way beyond me; however, look at the Finnish F-16, they were in CLEAR skies when they encountered their ash cloud and engine damage. Flight TCX952P a Thomas Cook Boeing 757-28A being ferried to Italy ran into Ash and suffered two instances of plugged bleed air valves and returned to Manchester. This was also in CLEAR air. The airline is denying the incident and is stating it was an air conditioning malfunction. Listen to the ATC tapes at http://www.liveatc.net/forums/atcaviation-audio-clips/tcx952p-turns-bac… and make your own decision (you have to register to actually listen to the files, it's free.) The pilot clearly states problems with the bleed air valves (which are part of the engine system that helps pressurize the plane, among other issues.) The Bleed Air has a separate warning indicator light and wouldn't be confused multiple times by the pilot if it was actually an A/C issue. Finally, today's occurrence with the Tornado encountering ash and suffering damage. Prior tests on airplanes show that some of the damage is microscopic and may not result in failure now, but what about years down the road after dozens of cycles (cycle is takeoff, pressurization, depressurization and landing) as stress on these microscopic cracks and abrasions? People expect these planes to suffer a full, all engine failure like the British Airways plane did with Redoubt, but there is a LOT more happening that is not visible, effecting the many different system, valves, sensors that may not be immediately noticed. In my opinion, this establishes a priority to study in more depth the patterns and wind effects of ash. There has to be a better way to monitor and predict the movement of the ASH cloud in the atmosphere. So it cost the airlines billions, how much do you think lawsuits and negative PR will cost the airlines if a plane crashes from the ash now?

If your flight has been cancelled today because of high level volcanic ash from Iceland, read this. Ted Nield* describes the first time a pilot (just) survived an encounter with volcanic dust, 11km high.

Geoscientist Online 15 April 2010

âGood evening ladies and gentlemen. This is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress.â

Captain Eric Moody, flight announcement, 24 June 1982.

On the clear, moonless night of 24 June 1982, Scheduled BA flight 009 took off from sweltering Kuala Lumpur bound for Australia. There were 249 passengers on board the plane, which was laden with 91,000kg of fuel for the five-hour flight to Perth.

At the controls was Captain Eric Moody (pictured recently). As they levelled out at the 747âs cruising altitude of 11,300 metres, the crew ate their evening meal, just as the flight passed south of the city of Jakarta.

Everything was routine; though âroutineâ for a jumbo jet involves some fairly impressive figures. For example, through each of the aeroplane's four Rolls Royce engines, 150 tonnes of air was being sucked every minute. Think about what volume of air you need â even at sea level - to weigh a hundred and fifty tonnes.

This may be some help. A cubic metre of air at sea level weighs 1.204kg at 20 degrees Celsius, according to the International Standard Atmosphere. But at the cruising altitude of flight BA 009, one cubic metre of air only weighs about 360 grams; so the 600,000kg of air that Speedbird 9 needed every minute occupied a space of about 1.67 million cubic metres. This means that, up there, in a mere 10 hours, one thousand million cubic metres of the Earthâs atmosphere will pass through a 747's engines. On its round trip, the KL to Perth service would gobble up about a cubic kilometre of the Earth's atmosphere. These facts were to prove significant in the tense moments ahead.

The function of all this air entering the maw of the jetâs engines is to undergo compression and mix with some of the 91,000 kg of kerosene that is squirted into it from fine nozzles. These are surrounded by "swirl vanes" that break the fuel into a fine mist - rather like the spiral grooves inside the head of a domestic spray gun. The mixture is then immediately ignited. Oxygen in the air combines with the fuel, at over 700°C. The massively expanding exhaust gases exit the four engines and thrust the aeroplane forwards at 800km per hour.

The speed of the plane was also to be significant in the coming moments. The difference in speed between plane and air means that anything in the air will collide with it at about 222 metres per second. A rifle bullet, by comparison, can travel at anything between 180 and 1220 metres per second. So it is a good thing, then, that under normal conditions there are no rocks in the air, 11,300 metres up.

Unfortunately on that night, there were - but nobody could see them because their average diameter was only seventy five thousandths of a millimetre. Worse still, the temperature in the engines was high enough to melt finely powdered rock.

His dinner eaten, Captain Moody left the cabin and made his way down the spiral stairs to the first class section in search of an unoccupied toilet; but before he could find one he was called back. Moody remembers noticing as he turned some little puffs of what seemed to be smoke issuing from vents on the floor. There was also an odour that reminded him of the smell left behind after electrical sparks have flown.
When Moody reached the cockpit the crew had already switched on the seatbelt signs and the engine igniters, to support the combustion of the fuel, just in case. The windscreens were lit up with the most impressive displays of St Elmoâs fire the captain had ever seen. The weather radar, though, showed nothing unusual. Then the First Officer pointed out that all the engines appeared to be lit from within by electrical discharges. In moments, the St Elmoâs fire changed to something resembling tracer bullets. Almost immediately, Roger the Senior Engineer called: âEngine failure number fourâ.

There was a pause. Then he announced: âEngine failure number twoâ¦.threeâs goneâ¦. theyâve all gone.â

Moody said: âOK Roger, put out a Maydayâ.

13.44 âJakarta, Jakarta, Mayday, Mayday Speedbird 9. Weâve lost all four engines. Weâre leaving 370.â

Captain Moody struggled to understand what was happening, because it contradicted many of the assumptions that underlay the emergency training of every airline pilot. Four engines simply donât fail, for a start; but when rehearsing for that near-impossible scenario, simulators assume that there would also have been massive electrical failure too, leaving everyone in near darkness. Yet the instruments were all working and the lights all on. The auto-pilot was also in control. The displays, moreover, were contradictory. Airspeed was falling, yet some lights suggested the failed engines were overheating. The Jumbo had now become a glider, but Eric Moody put it into a shallow descent on autopilot and bought some time to think the situation through.
As the other crew members went through the manuals performing the necessary checks, Moody thought about what it could mean. Electrical failure was ruled out. He checked the fuel flow. He checked for icing. Nothing. Everyone on the flight desk remembered thinking one thing: âWhat have we cocked up?â

As they descended through 7900 metres the cockpit pressure warning horn blew and the crew put their oxygen masks on. Roger, the First Officer, found to his dismay that, for no apparent reason, the mask fell apart in his hands. This forced a decision on the Captain to begin an emergency descent to an altitude where the air was more breathable, rather than risk losing his first officer to anoxia.

They were now heading back to Jakarta, but the safe limit around that mountainous region is about 3200 metres. The crew decided they would turn the plane back to sea and ditch if they fell below 3600 metres. Moody also kept the landing gear up, just in case they had to land on water but found themselves unable to retract it again. At about 6100 metres, Eric slowed the descent; but by this time Roger had been able to put his mask back together.

All during this sudden steep descent, the crewâs continuing attempts to re-light the engines had been visible to the passengers sitting aft of the wings, who now thought that all four were on fire. While the crew wrestled with conflicting airspeed indicators and wondered if they had been trying to re-ignite the engines outside their re-light envelope, the pressure in the passenger cabin fell enough to deploy oxygen masks, which promptly dropped about the passengersâ ears from the overhead lockers. It was at this point that Captain Moody thought it prudent to deliver his reassuring message, quoted in the epigraph.

Moody was now faced with the possibility that he might have to attempt a touchdown on the sea with all engines failed â something discouragingly known in the trade as a âdeadstick landingâ. He remembers thinking about how with his father, he had watched from Hythe Pier as the flying boats landed in the channel, and reflected that flying boats never flew in darkness because of the near impossibility of judging a planeâs height above water at night. But at this moment engine number four, the first to fail, became the first to re-ignite. Another 90 very long seconds passed before the other three did likewise just as the flight hit 3600 metres â the point of no return.

13.57 âSpeedbird 9. Weâre back in business. All four running. Level 12,000.â

Fifteen minutes had passed since the Mayday, but the adventure was not quite over. The crew wanted to climb to a safer height to clear the mountains ahead and climbed to 4572 metres. But no sooner did they reach that height than the St Elmoâs fire started again. Moody was convinced that this phenomenon was somehow connected to the engine failure but decided to descend to a level where the fires went out. As they came in to land, the crew also found that they were unable to see the landing lights properly and asked for them to be turned fully up. Slowly it dawned on the crew that the front windscreen was almost opaque. They landed partly by squinting through of the outer edge of the left hand front window, the only area that was still transparent. The passengers loudly applauded the final smooth touchdown.

Dusty answer

Two days later, the crew had confirmation of what had caused the incident, but Barry the Flight Engineer already knew. As they had waited for the passenger steps to be rolled out, he had noticed that his hands and uniform were covered in fine, grey dust. In fact they had flown into a cloud of volcanic ash, emanating from Mt Galunggung, 110 miles east of Jakarta. The plume only became visible to the weather satellite photographs of the time some time later.

This was what had blasted the windscreen to opacity and taken the paint off the plane's leading edges, but it was the engines that were the worst affected part, as they each processed their 1.67 million cubic metres of air per minute. In that volume of air, dust clouds do not have to be very thick for tonnes of the stuff to lodge in the hot moving parts. What is more, apart from wearing them away, the silicate mineral particles melt and fuse as they come into contact with hot components.

If you have ever owned a domestic anthracite furnace, you will know that it is often necessary â perhaps after a period of particularly cold weather when the fire has been allowed to burn high - to rake out clinker, a solid rocky mass of coal-ash (the unburned silicate mineral portion of the coal) which has fused at high temperature into a lump that will not pass through into the cinderbox, clogging the fire. Steel and coke furnaces also have to be regularly cleared of such clinker.

The first effect that the dust had on the Rolls Royce engines of BA009 was to change the shape of the blades by abrasion and so impair the efficiency of compression. Because it had been the first to be shut down, engine no. 4 was the least damaged in this respect. Ash filtered into and blocked the aircraft's pitot tubes â forward-pointing instruments that use outside air pressure to work out the aircraft's speed â so explaining why the crew received conflicting airspeed readings. Environmental control system ducts were worn away from the inside by the abrasive dust, explaining why the floor vents had appeared to be smoking. And in the engines themselves, the swirl vanes surrounding the fuel nozzles, which turn the fuel into a mist before burning, were also clogged. This meant that although the nozzle was able to pass fuel at the design flow-rate, the clogged vanes inhibited its atomisation, making re-starting of the engines more difficult than usual.

Apart from the obvious reason why having the engines of a jet airliner cut out all at once is undesirable, and even assuming the pilots do the right thing and land the plane safely, the repair bill is also not a trivial consideration for airlines. Seven years later, on 14 December 1989, Redoubt Volcano in Alaska erupted. The next day, a KLM 747 with 231 people on board entered its ash plume at 7620 metres. After an experience very similar to that of BA009, involving a steep dive of over three kilometres, the crew landed the aircraft safely at Anchorage on two engines. But the repairs to the plane â including a paint job and replacing all four engines cost $80 million.

What to do

Obviously the best advice to any pilot about flying into ash plumes is "don't". Hence todayâs disruption.

This blog was busy for almost two months following events at Eyjafkajoll from the first major EQ swarms at the beginning of March 2010, onward to the lava eruptions at Fimmvörðuháls and all through the most recent aggressive eruptive phase. Even Spring Break on the Eruptions blog was far from quiet. We kept up enthusiastic information sharing, discussion, links posting, monitoring commentary and round-the-lock watch for signs of impending surface eruption elsewhere.

None of us were caught unawares here when the crater erupted in phase II - if anything, we were glued to the action beforehand because of the incredible EQ activity bust that preceded it. Many of us stayed up all night, and more than one of us felt strong twinges of mixed fear and satisfaction at seeing it.

We knew something big was up and were lucky to have Jon to provide a direct inside link in his active monitoring of events at Eyjaf with his geophones and James with his fly-on-the-wall reporting of what the experts were saying, at least in casual conversation. And we had Erik, Boris and Ekoh providing technical explanations and interpretive corrections that helped us keep pace with emerging data as events unfolded.

We know conclusively that the Institute/IMO meteorologists, geologists and civil emergency response managers weren't caught out either, even through both eruption phases started very close to midnight.

What did happen is this: we had unexpected wind patterns that spread ash over most of Western and central Europe. We had an unexpectedly vigorous fine-grained ash and steam eruption that was far more voluminous than expected.

And we had limited explicit experience within NW European congested airspace traffic in dealing with this type of eruption brought on unusually stable weather system.

We did warn that it would be slow moving and would not dissipate quickly. No surprises here.

The unthinkable is that the air traffic authority appears to be acting as though this isn't going to happen again soon. There is no talk of contingency planning or emergency proration to mitigate affected flight through rescheduling as the next major plume event emerges into European airspace.

There have been no posted warnings of future air space closure should eruption intensity suddenly pick up, or god forbid, a second volcanoes joins the party.

They have GOT to be kidding.

Flying = short-term â¬'s

So no, they're not kidding. Maybe a plane 'should' crash to make clear what they're dealing with, although I agree with Erik: whatever decision will be made at future eruptions, it'll never be good enough. Let's just hope politicians won't give in to commercial pressure beyond the point that it's really going to be dangerous. The Dutch minister of Transport, Public Works and Water Management (Camiel Eurlings) already gave a shot at it... o_ô

I just hope I can fly to Scotland on May 1st ;-)

The sky has cleared slightly over the glacier. The plume is visible, but the crater is still hidden under a far-too-thick cloud. Of the MÃla cams, Hvoll and Ãóra show only a white plume, but Vala appears to show a black plume as well.

Passerby, thank you from a lurker here. It still mystifies me that so few paid attention to the warnings. In addition to this blog, Accuweather predicted the unique weather conditions over Europe that would keep the ash cloud suspended there; NASA photographed the ash migration; Icelandic authorities did their best in warning people -- and still most, caught up in their holiday plans, didn't pay attention.

And now they are so obsessed with recriminations over revenue lost, and disasters that didn't occur (since air traffic was grounded) that it appears that little or nothing will be done to accurately assess the risks from the next volcanic ash cloud event -- until there is an actual disaster costing human lives.

Victimology at its finest...

I think the plum is ash and steam. With the sun at the angle it is right now some show a almsot all white plume but with the sun shininh right on the plume it overexposes it. Another view shows a more plume with alot more grey to it which I think is what color it really is. The fact that only the edges are white but the rest is grey proves my point.

Exactly. The plume looks so much darker on the SE side, out of sight to Hvoll (the cam at Hvolsvöllur) and Ãóra (the cam on Mt. Ãórólfsfell). So, out of habit I said 'black' instead of 'ashy-grey'. To quote those infamous words: "Shit Happens."

I'm happy to find this site where i can gathering informations about eyafjallajokull. I also learned couple things, so i would like to thank all of your great and constructive comments...but i have a question...do you think that is any link between eruption of eyafjallajokull, katla and laki erruption in 1821-1823. Or in eruption of Katla and Askja in 1918-1919 (i read that Earthquake Swarm was ocured near Askja few years ago)

There is for sure ash mixed in with the steam. It almost looks like ash is in the front and the steam from the rear of the crater.

Andrew slight correction the Finnish Air Force aircraft were F18 Hornets, not F16s. A second report of Nato F16s suffering engine damage is circulating. These will be either BAF Belgian Airforce (seen reference saying they were BAF) or KLU Royal Dutch Airforce. Also the RAF aircraft are Eurofighter Typhoons from the training Operational Conversion Unit at RAF Conningsby Lincolnshire.

I actually live in the UK close by one of the major upper airways Upper Bravo 4 that sees a lot of tramsiting high level transatlantic traffic from the Continent. Very quite at the moment, very little traffic yesterday and today. The airspace just above where I live is military controlled and sees quite a few of the Typhoon training sorties from Conningsby overhead, quite often climbing and turning with afterburner. There were a few Typhoon sorties heard overhead yesterday and also a Harrier up from RAF Wittering, but today nothing at all. Wondering if the RAF are keeping most of their aircraft grounded. Also normally see quite regular high level transits of USAF C17's and C5's heading from the US into Germany and then onto the Mid East. These have not resumed as yet either. Are the military just a little more cautious?

The lessons of the 2000 NASA DC8 that flew through dispersed ash from Hekla is the incident that to me flashes caution. The aircraft flew for 46 hours with no incident before engines were fully examined and it was concluded serious failure could have happened within another 100 hours of flying. From the few incidents that have been reported the next few weeks could be interesing for any aircraft that have flown through ash. Keep my feet on the ground for the time being.

Passable VFR there. Too bad the Coast Guard has already called off the geology flight planned for today.

The Ãórólfsfell webcam (eldgos.mila.is/eyjafjallajokull-fra-fimmvorduhalsi/) clearly shows ash being emitted in relatively low fountains, at the left base of the eruption column. It's not much ash compared to the first few days but it keeps going. And the eruption column is certainly more impressive than one, two days ago. Volcanic tremor, on the contrary, had calmed down a little bit (hraun.vedur.is/ja/Katla2009/gosplott.html).

For the moment.

Changing the subject - a good exercise for the future is to get acquainted with Katla right now when we know there is no eruption, weather & visibility are tricky and there's cloud seemingly coming up out of nowhere in the middle of the picture. http://www.ruv.is/katla

Looks almost picture-perfect on Hvoll.

Does anyone know if the original fimmvorduhalsi fissure has stopped erupting ? It seems like an age since i was watching that webcam.

Looking just to the right of the plume on Mulakot and Hvol cams I see what looks like it could be another, low plume. Could be clouds I suppose, but doesn't quite look right> Could be steam shadowed by the higher plume

Cut-and-pasted a grab from Hvoll a few minutes ago. Despite the plume being overexposed, it looks almost yummy enough to eat.

@Zander, That eruption did finish two days before the eruption in Eyjafjallajökull main crater started. They are in the same mounted, but there are local names there, like in most places in Iceland. So more or less has Eyjafjallajökull been erupting for one month now.

http://hraun.vedur.is/ja/Katla2009/gosplott.html

Also now a spike in the tremor charts. I'm curious how these will match-up eruptions/tremor charts.

Is it just me, or is the plume getting ashier?

The picture on the Vodafone cam is gorgeous ...

@ Jon Frimann, thanks i'd been watching the fissure eruption then missed a few days, when i came back the main eruption had started. Did you find out what was causing the noise on your helicorder earlier ?

Looking at the Thorolfsfelli cam for several hours, I have the distinct impression that there are two active vents. The southernmost continuously erepts large volumes of mostly white steam whereas the northernmost one (closest to the camera) intermittently emitts relatively speaking much smaller, ash-rich, dark grey plumes. Sometimes, this has been clearly visible in the Hvolsvelli cam too.

@Anna: I want to frame it on the wall.

Hi there!

I´ve been looking at the glacier on the Vodafone cam, there is a huge amount of ice that has melted. Look here at 17 of April http://picasaweb.google.com/102175391233488315229/EyjafjallajokullVolca… and today's picture http://picasaweb.google.com/102175391233488315229/EyjafjallajokullVolca…

Have you seen the large crack that follows the glacier tounge towards the top?

Eck-eck! Vodafone.is just got slashdotted to spam!

@Karl UK

:) Thanks Karl! I KNEW it was F18's not sure why I typed 16's. Probably cause I saw that story about the Nato F-16's and just didn't realize it as I typed. Also, I meant Typhoons, and not Tornado's :P. They're calling for some tornado's in the southern part of my state here tomorrow, so I was just done reading that... I think I need to take a break! Too many errors in my post! :) Though the Thomas Cook info is correct! 1 out of 3 accuracy, ouch!

Fortunately, only for no more than a minute... I think.

http://www2.norvol.hi.is/page/ies_Eyjafjallajokull_eruption

Agree with our observations!

The Met Office recons that there'll be a layer of ash at 20.000 feet over the Keflavik and ReykjavÃk airports and environs tomorrow. So they're not closing the Icelandic airspace; passing planes fly at a higher altitude.

Looking at the web cams it seems to me that the heavier components of the ash are falling down to the ground not far away from the volcano.

The finer and ligther components drift off in the wind and go far and wide -- perhaps they even ascend to slightly higher altitudes?

Am I right?

Boris?

The airlines pretend to object to the airport closures, but the closures really mostly benefit the airlines. Probably there would have been no crashes, but the engines would immediately need to be overhauled, at far greater expense than the canceled flights.

The airlines don't want such expenses, but don't want to be blamed for avoiding them, so they make the civil authorities the bad guys.

@ Henrik (112)
I agree.

This from the iceland met office;
http://en.vedur.is/weather/forecasts/atlantic/
North Atlantic weather forecast shows that, if the V picks up activity though friday, it's all going the way of newfoundland. If really big, new york...

i swear i just saw some lava go up from black steam at poro cam

Just witnessed lava bombs being ejected on Valahnúk cam.. I do hope the cloud stays away tonight.. lol

The weather was awful, the pilots gave up, we went home, and now look at it. Perfect weather! This is unbelievably annoying!

I can't even look at it... :(

Thats a shame James... do you have any idea when you get to try again?

The Ãórólfsfelli webcam starts to show a reddish glow at the bottom of the steam / ash column. Let's hope the clouds stay away tonight, it might get spectacular.

Sorry James, I feel for you...

Of course, the moment I post about the views on the Ãórólfsfelli webcam I get disconnected. Looks like the site is too busy again...

But the most recent picture from the Vodafone cam on the picasa site also has that promising reddish glow at the bottom of the steam / ash column...

The pilots thought Monday at the earliest because bad weather was moving in, but this gives me hope that it'll be ok tomorrow. If it is, then we'll try then! The journalists are all still here anyway, because Keflavik airport is being closed tomorrow due to the change in wind direction towards Reykjavik and the risk of ash.

A surprisingly well-crafted article from the Guardian UK, April 20

Why aviation industry has cloudy knowledge of risks from volcanic ash.
http://www.guardian.co.uk/world/2010/apr/20/ash-cloud-aviation-industry…

'"It is almost impossible to define a flight corridor," said Dr Grant Allen at Manchester University. "The models cannot give you enough information on where the cloud is going to be thick and where it will be thin." Weather balloons sent up earlier in the week revealed a 600m thick layer of ash at an altitude of 2.5 miles. The layer contained highly abrasive particles at concentrations of 300 micrograms per cubic metre.'

Also, contrary to post #6 above, 'On Sunday, British Airways flew a test flight from Heathrow over the Atlantic and back to Cardiff, but only after a research plane had flown the same path and declared it clear.'

And a artsy bit from The Economist, noteworthy only for citing the supposed new limit set on ash concentration (2000 ug/m^3 - that;s micrograms per cubic m of air) deemed to be dangerous to jet aircraft, published today:

Disasters are about people and planning, not natureâs pomp (http://www.economist.com/displayStory.cfm?Story_ID=15951696&fsrc=nlw|hi…

The Guardian article suggests that wind tunnel testing was suggested and declared to be of limited use by aircraft manufacturers. Doesn't say when that option was brought up.

It does make important mention of detection methods employed by met centers monitoring ash cloud dynamics by laser, but with a limit of 5-8 km resolution, far too little to be of use for accurately predicting the flight path clarity with any precision.

The technology will have to be on-board, using inflight warning systems.

Looks like both Vala and Ãóra are showing The Red Stuff.

I'm pretty sure that 2 vents must be active...but of course i'm no expert :)

She has been pumping out quite a bit of dark grey almost black ash for the last 20 mins or so and in the last 5-10 mins has produced a few explosions in the crater, launching out even more thick ash and lava bombs.

From my study of all the volcanoes here in Florida, I agree that there are two vents. ;>) Actually I thought I noticed that earlier but it was hard to see.

But i'm sure that i'll not go to bed anytime soon, and it's already over midnight in my country :)

Starting to see red, over the rim of the crater on the mila cams. Beautiful stuff.

And the VAAC's purpose is now WHAT? Its now been gutted by politically correct, references to models (sounds like glowball warming with no damned hockey sticks) and well, empirical evidence of ash. If its there the level hasnt been established for a killer amount, or hours between inspections. Indeed just the opposite. When it has come down to safety they just said to hell with it and lets see what happens.

So far I am aware now of 6 incidents, one of which has required an engine off the pylon and that in itself is enough to tip it over.

Oh-And the passengers are so oblivious that personal responsibility, the very thing that gets this ball rolling is totally ignored. Why? Because the powers that be said it was safe.

Is it?

You tell me.

Cite your sources, reasons, and I will be more than happy to eviscerate your argument with all of the knowns that are out there. Quite frankly in light of the knowns I would say that a charge of manslaughter would be in order if something happens.

Clouds are fast approaching :-(

I'd suggest now would be a grat time for our friend jim to take hisa chopper ride.

not clouds...please!!

P hope you´re watching the Mila cams, great show with lava eruptions

Vala cam just giving us amazing show

Definitely spitting fire now.

The Poro cam isn't disappointing either, and with the fast dimming light the explosions are starting to become visible on the Hvo cam too.

@M. Randolph Kruger, If I go to mainland Europe when this eruption is ongoing, I am going to take a boat. Not a air plain. The risk is currently too high. As sad before somewhere here, they are asking for a disaster to happen soon. It is just a question of time.

No political correctness is going to cover that up.

One for all the astronomers among us: On the Vanahnjuk mila cam,top left above the ash plume. Is that venus up there?

Although I still think there may be two vents, our observations could be explained by a single vent where water runs into it on the SSW side and the lava fountains occur on the NNE side.

I've been reading with interest peoples statements re 2 vents... Been trying to see a second vent but only see the one, can anyone explain why they think there is two, maybe point out the second.. thanks

Yeah... Eyji is definitely making like a TV evangelist - spitting fire and brimstone.

Slightly decreasing tremor charts during heavier dark grey to black ash and fire.

Activity at Vala is really impressive, very ash-rich Strombolian, almost Vulcanian..

M.R. Kruger (137)

I think the people with all the arguments have already left these quarters :)

@ Eddie (146) I'm not an astronomer, but don't have to be one for identifying Venus. If the camera looks west, that is sure to be Venus. Well, as for hraun.vedur.is weather map, there is an E wind blowing in the region of Eyjafjöll, so the plume also directs W, so I say BINGO, that's Venus. :-)

I am seeing in my formulas (that I keep in my head) that there is a risk of a explosion in the next 72 hour frame. But I must warn that this is the most difficult and most likely formula to get it wrong that I am currently running. So be prepared for that if nothing of interest happens at all.

Currently I am unsure why this might happen, but a new fissure opening is the most likely reason that shows up in my formulas. But that formula is also rather uncertain, as before.

So far the deflation in Eyjafjallajökull is now ~20mm movement to north, and there is a inflation to west. But that is quite interesting fact. I guess that there is plenty of magma down there given those facts.

@Eddie: The only object I can spot in the approximate direction is the moon. The sky here is clear, so I should definitely be able to spot Venus or Jupiter.

@ 148..
On Vala's cam, there's some visual evidence of 2 vents, one discharging black ash, in front of another which is fire-fountaining.

No way to know for sure except to look at it from above at close quarters, or to use high-resolution IR imaging to see through the steam..

M. R. K @137;

Oh-And the passengers are so oblivious that personal responsibility, the very thing that gets this ball rolling is totally ignored. Why? Because the powers that be said it was safe.

Is it?

That's why no libertarian platform is ever going to gain more than trace-level electoral support. You're not wrong. But generally, people are not prepared to take that level of personal responsibility. They welcome the opportunity to trust others' judgements when they don't have the expertise/training.

Shelly! See #112, I also have a screen capture showing two plumes - one white, one dark grey - side by side from Hvolsvelli (22.18 GMT)

Thankyou Volcanophile for explaining that to me, now you've said it it does make sense..

And in the middle of this Dana Milbank mocks concern about volcanoes:
http://www.washingtonpost.com/wp-dyn/content/article/2010/04/21/AR20100…
I'm a bit confused at his angle here. Is he confusing the fact that we can't stop volcanoes with the fact we can monitor them and be prepared for various scenarios? Is he just using it as an example to mock congress? Or did he envy the attention Bobbie Jindal received for doing the same thing?
You can ask him here:
http://projects.washingtonpost.com/staff/email/dana+milbank/

@ M.Randolph Kruger, personal responsibility is exactly right.If people choose not to fly they might lose money to the cost of a flight , a hire car and some hotel rooms. However if people choose to fly and something goes wrong then it's their ass, i know which i'd choose :)

Jon Frimann in Iceland
What are you evacation plans - you have that in your model?

@JB, I live ~200 km north of Eyjafjallajökull. So I currently have no worries. The closest volcano that I have nearby is at ~85 km distance from my location. So no plan needed for Eyjafjallajökull at any given time. But I might need to prepare for ash fall if the wind changes in my direction.

@Jon Frimann..

It's really impressive to be able to forecast 3 days in advance, what will go on at a volcano... I'm truly amazed that it may even be possible to do that, since 72 hours is an awful lot of time, and there is currently no activity on the IMO earthquake map at Eyjafjallajokull.

This brings me to a question I really don't know about, and I would be very happy if someone explained it to me (in not too deep a fashion, since I'm just a humble volcano-watcher, I'm no geoscientist at all ;)

Harmonic tremor is made by ascending magma through the magmatic plumbing of the volcano, and by associated phenomena (rock-fracturing, gas depressurization).

Is tremor proportional to the level of activity at the volcano at T-time (it only monitors the ongoing activity), or is it proportional to the strength of what will happen at the volcano in a short time?

Thanks a lot for the answer, and sorry for my broken English, as it's not my mother language..

Thankyou Henrik, I have been grabbing some screen shots myself this evening of the twin coloured plume, this one shows it very clearly, I like the way it has twisted together but not merged into one..

http://www.flickr.com/photos/39750392@N05/4543898997/sizes/l/

It did not occur to me that this could be two seperate plumes. lol

@Volcanophile, I am working according to a idea that I had. Currently I cannot say that is guaranteed to work. I have less then 5% success rate I would think in total. But as the time passes I should be able to make a better idea and formulas for the time when I can write the up as real theory for the science progress.

@ Reynir (155) Jupiter is only observable by early dawn at a very low altitude. I think Moon must be much brighter as it is a waxing Moon now, it is at a lot higher altitude than Venus. By the direction and the position it must have been Venus.

Eyjajallajökull erupted because of Top Gear :) http://transmission.blogs.topgear.com/2010/04/16/1990/
http://translate.google.com/translate?hl=en&sl=is&tl=en&u=http://mbl.is…

Top Gear was at the volcano http://transmission.blogs.topgear.com/2010/04/16/1990/

@Jon: Thanks a lot...

But this is a thing I don't really know what to think about it, or rather what to hope about it...

If your theory is exact, you will make science progress, but Eyjaf will enter another explosive phase, and it will be devastating to European air-travel, yet again..

On the other hand, if Eyjaf won't blow up, Europe will be spared, but it would mean your eruption-forecasting model needs some more tweaking...

This is where pure science and human/economic factors collide head to head...

Original story (http://translate.google.com/translate?hl=en&sl=is&tl=en&u=http://mbl.is…)

Dr. Erik,

Meteorologists responsible for public safety (e.g., warnings) are often in a no-win situation as well when it comes to severe weather warnings.

It's nice to see that while conventional weather radars (5 to 10 cm) may not be able to 'see' the suspended fine ash particles, specialized, upward pointing radars using much smaller wavelengths (infrared or ultraviolet laser light), _are_ able to detect it:

http://sirta.ipsl.polytechnique.fr/bdd/pub/basesirta/1a/lna/2010/04/17/…

Its the bright red line/returns from 3-km descending to 2-km later in the day on the 17th over Palaiseau, France (north of Paris).

The bright red patches at higher elevations ~9 to 10 km may be falling ice crystals from cirrus clouds -- virga or hairstreaks.

Numerical models like the UKMET and ECMWF are very good with upper-air trajectories. What is not so well known is the fallspeeds/removal processes of ash; and what is harmful to jet engines. Obviously, particles the size of sand is bad, but then you're too close to the volcano anyway if the engine is sucking in such large particles. How fine can the ash get? down to 1-2 microns? like cigarette smoke? Can jet engines handle that okay? Does anybody know?

So many unknowns. Better safe than sorry.

Thanks for the many informative blog/posts here.

To my best knowledge, the camera looks south-west.

Also, the moon would be more than a single point in that picture; a recognisable crescent. The point I saw could have been a bright star or a planet only. Gone below the plume now :-(

Let me repeat: many stranded European passengers were taking advantage of the holiday break to travel.

That's nonessential travel. Low rates of the past month and thrift fares were meant to encourage air travel after a prolonged industry downturn due to economic recession and tight credit controls.

Unfortunate timing, but it does raise the issue of reducing risk by reducing flight traffic in potentially affected air corridors when there are satellite indicators of increasing plume density and the Met folks are seeing weather patterns that may cause plume stalling over the North Atlantic and Western Europe.

At that point, airlines can choose to cancel or postpone immediately pending flights and send email alerts of potential cancellations in the upcoming days.

Their approach may include sending out immediate travel advisories to customers, offering incentives for future discounts or full refunds to nonessential travel ticket holders to willing cancel or postpone travel plans, if they cancel within hours of receiving notice (by email or automatic cell phone texting).

The travel industry -hotels and car rentals, for instance - will be asked to go along with these special conditional travel advisories to cancel bookings without penalty. They may choose to also offer incentives to customers for early notification, removing the confounding confusion of last minute changes.

It's another approach to just-in-time risk controls.

Essential travel, for medical procedures, government and corporate business will carry mandatory risk release and pilots and flight crews will need special insurance instruments (agreements) for work under higher, but acceptable, risk conditions.

To ensure 'acceptable risk' these planes could be retrofitted with blah-blah-blah FL-dual sensors (not going into technical details here) with on-board automatic warning systems.

That's how I see the airlines managing risk while continuing to fly under adverse conditions that are likely to occur in the immediate 12-36 month time-frame.

@165 Shelly: I caught that 2nd grey ploom as it when it first emerged

http://img135.imageshack.us/img135/5898/14flugv.jpg

Yep.. Top Gear is to blame for every evil in this world...

When Eyjaf saw J. May drive by with his gas-guzzling very eco-unfriendly CO2 factory, it said to itself... the h*ck with that, I can put out WAY more CO2 and toxic gases than you do with your trashcan on wheels, you amateur, and I'm gonna PROVE it... I'm gonna blow up straight into your face..

And that, Eddie is what bamboozled me. It had to be a star, but there was none of the magnitude I expected in the direction I was expecting to see it.

Thanks Volcanophile, that made my day! :)

Has today activity of Eyjaf increased against yesterday?

I haven't seen seen any lightning in the cloud tonight. Does anyone know if there is a relation between large amounts of ash in the plume and lightning?

It's really a spectacular show tonight!

Re: Matic @179;

Hard to tell. May just be that the volcano has run out of glacier to melt so is more fiery than steamy.

http://www.springerlink.com/content/buvw2tq081013210/

What are people's thoughts on the Solar cycles and earthquakes and volcanoes. Looks like it's gone a bit quiet on that topic. The sun has just come out of very quiet period and all of a sudden there has been a large increase in volcanism and earthquakes. Is there any link at all?

My problem at the moment, is that there is too much politicization of the MET at the moment so basically I don't trust them anymore. The AGW pressure to keep forecasting hot summer and then vice versa occurs, and then mild winters and they the whole country gets frozen over implies some sort of either bias, not enough computing power and it is just not possible to do this.

http://www.4ni.co.uk/northern_ireland_news.asp?id=107895

I mean these computer models with the weather have been shown wrong over and over. BBQ summer forecasts etc etc. If these computer programs are so good at modelling the future, why don't they pick a few stocks for me over the next year, I'm sure the computer model could tell me what the stock market would do, it's not different to what the weather would do or an ash cloud.

I mean they have the new computers http://www.itpro.co.uk/610965/met-office-gets-30-million-supercomputer but I think the problem is they are trying to get the answers that they want to get.

http://wattsupwiththat.com/2009/12/24/bbc-botches-grade-school-co2-scie…

If you look at this experiment, on live TV. Can you actually believe any science that comes out of the UK at the moment. I'm just skeptical of everything that comes out now. How can some of the leaders in science do such a silly experiment on live tv? Remember it's an election year in the UK, and unfortunately there has been a lot of politization of science in the climate field.

@182 Interesting topic, my only comment is that in 2006 when NASA scientists were calling for the largest peak in modern history, they said it would be happening in 2010... Today is the 7th day with out a Sunspot. Not exactly peak conditions if you ask me.

http://www.spaceweather.com/images2010/22apr10/midi512_blank.gif?PHPSES…

In fact, we have had spotless days every year now since 2004 It will be interesting to see if we still have spotless days in 2011.

Maybe the increased awareness of ash and aviation hazards will finally help KVERT.
KVERT (Kamchatka volcano monitors) sent out this notice today:
http://www.kscnet.ru/ivs/kvert/updates.shtml
They don't have funding after May 1, and anticipate that they will cease operations on that date, barring funding.

Re: SP @182;

I can't think of a physical mechanism to link the phenomena. Solar cycle affects the sun's surface temp, solar wind flux and magnetism, but it's mass doesn't change so no effect on tidal fores that do contribute to volcanism.

Of course an increased solar wind flux can add more heat to the upper atmosphere, and this is noted and taken into account in global climate models, but it's too diffuse to strongly affect techtonic movement and is shadowed by the CO2 increase due to fossil fuel consumption.

It seems that gas turbine blades operate above the melting temp of the metal partly because thin surface coatings act as a thermal barrier: eg http://www.ul.ie/elements/Issue6/Gas%20Turbine%20Blades.htm
So these coatings remaining intact after encounters with ash? And a borescope inspection is an adequate test?

Have blade coatings been lab' tested in conditions that replicate exposure to 'volcanic ash'?? Is that part of airwortiness testing? If not, the engine manufacurers that have OK'd flights in air laden with ash must be out on a legal limb.
BBC reported today max. ash levels that are acceptable is 2mg per cubic metre air. So in 1 hour 100m cubic metres of air is swallowed (thanks Bob Chesson #89) containing 200m mg of ash, or 200,000g or 200kg. Hmmm...that's shot blasting, those blades will be polished nicely. [Did Beeb get it wrong: was it 2 micrograms per cubic meter?]

@ Zeke (171) Some Icelandic measurement details about the ash (I don't remember exact date, yesterday or one day before, I only copy/pasted these number for myself):
"About 24% of the sample is smaller than 10 μm (i.e. in the size range of aerosols), ~33% between 10 and 50 μm; 20%
between 50 and 146 μm and ~23% in the fraction 146-294 μm. "

Yes of course normal weather radars can't detect it, that's why lidars are needed. I'm not sure how many lidars (that are proper for this job) are operated in Europe, but with a good cooperation between them it would be much easier to measure the ash content of the atmosphere above Europe in real time. I hope we'd soon hear about it from official scientific sources too.

Good to see they are actually testing the plume in detail now in the field http://news.bbc.co.uk/2/hi/science/nature/8634276.stm

I would also say, that military jets would be more prone to damage, as they fly faster and have higher air intakes with more pressure and smaller hotter areas in the engines. Helicopters also have different types of engines and have the large rotary blade above which forces a lot of air downwards.

@eddie - I like to keep an open mind, if you think that the earth has a magnetic field which originates from the core of the earth which is the molten magma. The earth magnetic field does get pushed around by solar winds and storms, two forces are interacting with each other. Could this change the shape of the magma inside the earth enough to cause some activity? Did you see the great images yesterday with the new Solar Observatory, I think a lot will be learnt over the next few years, NASA already says one theory has been already disproven (they didn't say which one). We know that moon quakes occur from the gravity on earth, and the moon's gravity can have some effects on the crust, due to tidal forces. Maybe the sun has some effect, the sun does not just release visible light, there are many forms of energy coming out of the sun, like electromagnetic, particle and neutrinos which hit the earth. It would be interesting to see if there is a link. In regard to CO2 how did we go into the Roman Period, Medieval Warming Period and Little Ice Age without a change in CO2? How did we go into previous Ice Ages with higher CO2 then currently. I was asking about the sun's effect on earthquakes/volcanoes not the weather LOL :P

@Scarlet (182)
Statistics is a kind of method to connect things even if they will never have any connection. :-)
Many great eruptions had happened when the Little Ice Age was ruling our planet mostly because of a long period of solar minimum.-> en.wikipedia.org/wiki/Little_Ice_Age
I don not know about any physical connection of solar cycle and inner activity (eq-s, volcanoes)of our planet. By the way there might be some, even if we don't know about it now. Scientists will reveal it if it exists. :-)

@183 I think the problem in the past, was that sunspots were concentrated. We now even know that the energy is not actually from the sunspots, but the area immediately around the sunspots. But the sun sends out many different forms of energy, if we look at the sun in UV for example, we see active times when we though nothing was really happening. There are many forms of energy emitted from the sun, sun spots are easy to see, but the new observatories are seeing different energies that change that we had no idea about in the past.

The earth's magnetism is being found to be more and more complex. And essentially it all originates from the core of the earth, which is the magma/iron core. Since this is what powers the earth's tectonic system and even maybe lava plumes maybe there are some connections? More studies are worth doing instead of completely dismissing it now that more solar observations are coming in. We don't really know what causes the sun to reverse it poles every 11 years or so, or even what causes the earth to reverse it's magnetic poles or why this even occurs. It has been found that the earth's magnetic field has reduced 10% over the last 150 years. Why has this happened, interesting to note that Volcanism has also reduced over this period and the "warming" has also occured over this time period. http://helios.gsfc.nasa.gov/heliosph.html The heliosphere also needs to be looked at as well. The earth is not an isolated system, it is part of a larger systems, and there may be powerful external forces which may have some effect. These forces may be not greatly detectable, but over a large area they may have a greater effect, a prime example is gravity, a weak force but powerful over a larger area.

We can answer that question quite nicely.

First, we'll start with the source of the lidar figure mentioned in the UMBC Air Quality blog on April 17

http://sirta.ipsl.polytechnique.fr/bdd/pub/basesirta/1a/lna/2010/04/17/…

With the caption: Over France, the Paliseau station shows a similar layer (to German and Hungarian images) but a higher cloud of ash which was seen in the backscatter and in the depolarization channel of the lidar (this shows that the ash is non-spherical in morphology).

That blog entry also tells us who is doing the lookin' with lidar:

The World Meteorological Organization's Global Atmosphere Watch has encouraged a large number of list communications on the position of the ash cloud. GAW's Aerosol Lidar Network (GALION) stations in Europe are part of the Earlinet network.

World Met Organization:
http://www.wmo.ch/pages/prog/arep/gaw/aerosol.html

Polar projection map of stations in the northern hemisphere. Pay particular attention to the Left Coast of the US.

The European lidar group watching aerosols is Earlinet.
http://www.earlinet.org/index.php?id=235

This is their brief daily update log following the progression of the ash cloud.

http://www.earlinet.org/typo3conf/ext/naw_securedl/secure.php?u=0&file=…

Answer for Monika, in the blog cue because I had 3 links embedded in my reply post.

@eddie [185] and SP [182]

Dunno if it's any use to you, but I have always heard of the wild theory that quakes were connected to the moon. Like most I sort of dismissed it. Then a UC Berkley article came out that said that there was some connection... but that was about it, no specifics. (they were referring to the San Andreas)

Curious, I grabbed about a truck load of quake data from the USGS site, everything over Mag 1.0, by year, whole globe. I managed to digest about 5 years of it before job tickets, yardwork and data burnout got the best of me.

Of the 5 years, I extracted the Sun R/A, Decl, and distance; the Moon R/A, Decl, distance and phase for the UTC timestamp for each quake. After factoring out the dwell time that the Sun and Moon spend at each point in their respective paths, I can say that there definately is a connection... but I can't tell you what the mechanism is.

Here is an example:

- At new moon, the incidents of quakes (world wide) goes up about 200% (give or take)
- At 81% full moon, the number of quakes goes up by 43%.
- At 37.9 % full, 51% increase in quakes worldwide.

There are a lot of spikes in the data, but when you smooth it out, the over all tendency is for less quakes to occur between new moon and half moon, then rising until near full moon, then a rather sharp drop off. It wasn't what I expected, and no, I can't explain it.

There isn't enough data there to make any firm judgments... I only did the period from 2004 to 2010. Even at that, you're talking in excess of 130,000 data points.

Is there something there? Yup. What is it? BTFOOM.

Does anyone else see something strange on the Val cam?

@Monikia like you mean, if you get a big bunch of tree rings, and then pick out the outlier which gives you the result you want ? :P http://joannenova.com.au/globalwarming/skeptics-handbook-ii/web-pics/mo…

http://it.tinypic.com/r/7oqt/5 You are right, Iceland was very busy between 1300-1850. Many of it's great eruptions occured then. Since then, it's been pretty quiet. Indonesia's bigger eruptions were around 1816 Toba we had Krakatoa but no other large ones really since then. Speaking about solar activity 1857 had the giant solar flare that roasted all the telegraph wires, does this energy not get into the earth somehow? The earth is a electrical system, we see lightning and lightning in volcanoes and high energy sprites in the upper atmosphere which are almost as powerful as particle accelerators.

@193 - Renee, there is something going on there. Visual artifacts? Something up with the camera or connection? Pranksters again? Not sure, but it looks odd.

@Lurking I think the mechanism with the moon would either be the moon's gravity effecting the tides (moving water), pressing the plates (we know large bodies of water can effect the earth, with large dams that humans have created, we have moved fresh water into all these dams all over the world and this has slightly changed the spin of the earth)(Also dams when loaded cause earthquakes, so moving the world's tides around should have some effect). The moons gravity could be effecting the lava reservoirs in the volcano. I know a lot of Volcano climbers don't like to climb volcanoes on full moons when they are active, as they seem to be more likely to do something crazy (the volcano not the climber)? But the moons gravity would pull the whole core inside the earth in that direction, every action has a reaction, it's more obvious on the moon because the earth is larger, but on the earth it may not be as obvious - moon quakes, it appears to be the earth's gravity?

http://www.physorg.com/news63645811.html

Then you have the plasma/electrical physicists and their thoughts in regard to earthquakes and the earth's field
http://spectrum.ieee.org/computing/hardware/earthquake-alarm

i'll say that i se maybe for couple second that there are 3 vents?
But that is just because of steam rising up

Lurking @192;

That's exactly it. The gravity from the sun and from the moon pulling th earth's material in sometimes the same direction, sometimes different direction. It's the major, dominant cause of techtonic movement and volcanism.

SP reported a good idea with the magnetic (specifically, not electromagnetic) force of the sun on the earth's dynamo. The question is how strong comparably this can be.

I joing you both in hoping for more research in these areas.

@Scarlet Pumpernickel [196]

Oh, I agree that there is tidal energy involved. I just can't figure out why the spikes in quake activity occur where they do. Full Moon - easy, Sun and Moon pulling opposite directions. New Moon - also easy, Sun and Moon pulling in the same direction. 81% full moon, 37.9% moon? What the...

I even went as far as trying to see if maybe there was some connection to the dimensions of the plates. Again, referring to a couple of the oddities that I noted:

81% full Moon equates to a Sun - Moon separation angle of 128.473 Degrees. In radians, 2.2423, yielding an arc length of 14285.6 km on the Earths surface. (using a Earth mean radius of 6371.0 km)

At 37.9% full Moon, 75.6574 degree separation angle (1.3205 radians), and an arc length of 8412.7 km.

At this point, when you go dig up the dimensions for the various plate structures, you see some correlation, and a lot of just ... "stuff" that makes no sense at all. Where on that randomly shaped plate do you choose for the other end of the measurement? Is it a pivot point? If so, what sort of motion are you looking for? Is Jim Beam a better fit? Not wanting the headache, I opt for a beer and call it a day. Maybe look at it later. *sigh...

And the bitter part of it... after this spaz of activity in Iceland, I've come to the realization that there is a HUGE quantity of quake data that is not in my data set. Getting at that was a pain, seeing as the interface to the quake list doesn't seem to want to work. I managed to take apart the non-functional KMZ Google Earth data file, extracted the internal KML file, tweaked it so that I could pipe it into Excel as an XML file, and was able to get some decent plots of the 2009 / 2010 quakes in x,y,z scatter form. The cool part is that you can see the streamers rising up under the other Volcanoes in Iceland. The bad part is that there are other streamers rising up under the other volcanoes in Iceland.

Personally, I'm glad that there are geophysicists who get paid to look at that sort of data. Spooky stuff when you consider that the consequences are.

Is anyone else besides Renee watching the Valahnúk cam? We're seeing something unusual. It's not the red sprays and glow from the last several days. The color is whiter with some green and the light forms are different. Camera problems or prankster? I can't tell. Of course now that I post, it seems to have gone still. Headed out for the night so have fun figuring it out.

@202 Yeah would be great if more research occurred in this area. Really we don't know much about the core, it's iron, it's radioactive. The spin of the earth would determine the convection currents. The gravity of the sun would effect it as well, our orbit changes over time so gravity effects would change over time. But the strangest thing is how/why do the poles reverse. And is the sun somehow involved in this or is it just a spontaneous mechanism inside the core. We know from Io, Jupiter's gravity causes the eruptions, but does Jupiter's field also effect it? Io is sitting very close to Jupiter which has a very strong field as well, though it doesn't throw out particles in the same way as the sun does.

The sun produces so much energy in so many forms, it doesn't have all effects on earthquakes, but there must be some link and some predictive effect that can occur. Just look at the effect of the solar wind - auroras, maybe this electrical energy gets stored in the earth?

http://www.springerlink.com/content/n736466804232504/ we know there are some changes in the ionsphere with earthquakes/volcanoes, but still we don't know much about it.

The sun was very very quiet last year, it just started getting active again and then Iceland and others woke up and we had the large Chile earthquake again, maybe it's just coincidence? Maybe it's like the 1960s again, we had the large Chile earthquake, then we had further cooling on the planet for some reason not totally explained into the 1970s. Probably just co-incidence, but it would be interesting to map activity cycles over 100 years or so of volcanoes and different types of solar activity (but we don't have data on all the aspects of the sun as a lot of it is just starting to come now, we only really have sun spots)

http://news.bbc.co.uk/2/hi/science/nature/8637578.stm

Nice article, UK and Iceland were much closer :P

What a shame no webcam here hey? (Vanuatu)

http://www.radioaustralianews.net.au/stories/201004/2880742.htm?desktop

Peter there are NO standards whatsoever because there is no way to sample the air even with lasers. LADAR is short ranged and might even have to be space based to get a big picture. Passerby is right that it would have to be plane mounted for it to be effective out over the oceans. Even then WHAT would be the mission of the VAAC? To let them know its going to abrade the Sermatel coatings on the engines (basically a special epoxy) to prevent abrasions? WTF they are just going to fly anyway. Whats the diff?

No, its not just the engines that make the airplane a no go. The Air Data system is hugely important and they cant open that up to more airflow as it induces drag. Hell, we have to clean bugs out of them now. Guess what happens when ash gets in it with all of its corrosive properties?

No its simply going to take one going in to get their attention and the public will demand that SOMETHING be done. I have it...Run Friman Run, the EU, China and Russia will nuke the Ejaf volcano tomorrow. Is say 10 o'clock good for you?

Kidding of course but who are these idiots making these calls? Please put their names out there by authority so that the indictments when it happens can get it exactly right. Models? Crap, we are ready to toss away good common sense about the climate with hockey sticks.... What was this one? We had micro and visible ash, we had a volcano erupting to the oooohs and aaaaahs of the world.

Hells Bells-get your helmet and I'll meet you down at the flight line and we will test what could happen. Think its not a problem? Drive a plane through a plume for 20 miles and tell me it safe on the radio. I'll be at the bar listening intently.

Now that activity in the crater has calmed down, seismic activity seems to be on the rise again, this seems to have been the pattern for the last 3 days i have been watching it.

http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layou…

Iceland's airport closed for ash fall, the wind's changed? Did the global warming current malfunction now?

@Scarlet Pumpernickel [205]

Well, if you want to play the home game... Here are the top 11 spikes from the five year data set that I mentioned.

The easiest way to read this, is as an increase in quake activity is over whatever the normal background quake risk is. That's about the only way I can quantify it. Sep angle is in degrees, Arc length can be found by converting to radians and multiplying by the Earths radius.

83.7% full moon - 77.2% increase ; 133.3 S-M separation angle
87.7% full moon - 77.2% increase ; 138.2 S-M separation angle
57.7% full moon - 71.6% increase ; 98.3 S-M separation angle
55.5% full moon - 64.9% increase ; 96.4 S-M separation angle
59.8% full moon - 64.9% increase ; 101.1 S-M separation angle
64.7% full moon - 61.5% increase ; 107.8 S-M separation angle
82.9% full moon - 61.5% increase ; 132.0 S-M separation angle
81.0% full moon - 59.3% increase ; 128.3 S-M separation angle
67.7% full moon - 56.1% increase ; 110.2 S-M separation angle
61.7% full moon - 53.4% increase ; 104.1 S-M separation angle
37.9% full moon - 51.4% increase ; 75.7 S-M separation angle

Best of luck. This is only the top 11 of 415 spikes in the occurrence of quakes over 2004 to 2010 [from the USGS data set].

Folks, I think most people in these discussions are well behaved, but please, try to avoid the unnecessary snark, especially when it comes to issues like climate. I know we have strong feelings about this issue, but again, this is supposed to be about civil discourse, not crude jabs at each side. No reasonable scientist is taking every movement of wind as signs for/against climate change - in fact, amongst the scientific community, the discussion is relatively civil. Please try to keep a level of decorum here.

@207 I think the problem with the MET is that people don't trust it anymore, it's become politicized. After making several warm summer forecasts which were opposite, then saying the winter would be mild and the whole country gets buried in ice people are looking at the MET and thinking what the heck is going on, either they are trying to produce the result they want for the government, or they just are not good at forecasting. The supercomputers are pretty much fantasy machines, since until you can actually predict what each individual cloud is going to do or how many will form, it's pretty useless, which is pretty much impossible, as your trying to predict the future with a chaos system. In the end in March this year, the MET has ceased to make long term weather forecasts. They might as well use the super computers to predict the stockmarket, if they were so good at modelling and so powerful I think that system would be less complex then modelling weather systems.

I mean when such figures go on national TV and do such silly experiments (see link below, I really almost fell off my seat laughing when I saw them do this), I think you'd have to be skeptical about every announcement that comes out of the MET office or the current UK government, and with the ash cloud people are just skeptical like myself because I've just seen what's been coming out of that area for the last few years and they are using the same methodology to determine their result, the computer program is heavily relied on which not much observational data is occuring, sure they flew around iceland a bit, but did they test the airspace over Germany?

http://wattsupwiththat.com/2009/12/24/bbc-botches-grade-school-co2-scie…

http://newsroom.ucla.edu/portal/ucla/scientists-discover-surprise-in-10…

Interesting study above on the new energy delivered to the magnetosphere. Does this change the core?

@Eric - Yesterday Global Warming "blamed" the traffic problem by changing the winds http://finchannel.com/news_flash/World/62436_Global_warming_blamed_for_… as the winds blow the other way and ash falls on Iceland's airport is it global warming or did the wind just change again as it does all the time :)

Hope this isn't a silly question - but the colour changes I'm seeing on both Val and Poro cams - are they being caused by atmospherics or does the eruption glow colour indicate something like mineral content etc?

And here is my time lapse from the Mulakot camera for today: http://www.youtube.com/watch?v=5YbV6BIpXxQ

http://www.earthweek.com/2010/ew100423/ew100423d.html

Go Gaua ! Are Volcanogists starting to fly to Vanuatu?

http://www.wimp.com/mexicaliearthquake/

Interesting footage from Mexican Earthquake April 4th

Helen (#214), Carla (#204), Renee (#197)

I think the webcams are suffering some sort of malfunction, most likely on the software or connectivity side. Maybe a reboot might cure this strange thing.

Over the last hour I have seen individual explosions go forward and backward (really strange looking, that one!), spectral shifts from blue to (beautiful) purple, large pixelation artifacts in various colors etc. Clearly, there is some kind of bug in the system...

@214 Helen I believe it's a trick of optics/digital pixels for the most part. These are long lens cameras in very low light. Notice how it can be quite colorful and then quickly go back to basically black and white. Also you see pixels periodically. The light coming from the eruption gets distorted sometimes, almost like a prism.

Weird colours coming from Eyjaf tonight!! Often the glow is changing in various shades like blue, green, white and even purple. Looks like we have a psychedelic volcano!

I was able to do screen caps of one of each cam:
http://img402.imageshack.us/img402/4691/thorosfelliweird01.jpg
http://img22.imageshack.us/img22/7277/valahnukweird01.jpg

The strange colours seem to show more so in the Ãórólfsfelli cam than the Valahnúk cam. The screen cap from the Ãórólfsfelli cam is especially striking - it's very purple!

I wonder if it's because of either very localized lightning or the glow of the lava being seen through weather and ash clouds? Or is it burning gases coming out of the volcano in unusually large quantities? Or technical problems, maybe (bit of a stretch if more than one cam's having the same problem at once though!)?

Benjamin, bless you for your helpful video daily volcano activity synopsis links. They're a treat to watch.

The land-sea breeze patterns and rapid weather front progressions are remarkable, as are the lenticular clouds we see briefly forming as the winds still at dusk.

After dusk, the eruption activity diminished rapidly perhaps attributed to the sudden loss of convective air flows as the wind stilled, and was preceded briefly with a very small bust of EQs to the north that also ceased at about sundown (#208). Perhaps coincidental in timing.

Stiff winds for much of the day kept the plume column mixing height contained locally.

Looks like my questions have been answered anyways. Sorry, I'm not that good nor that fast a typist anyways, not to mention that it can take forever for any of my comments to load!

@Dan @ Holger - as I suspected, prob with the cam/software. However... I too noticed the colours appearing both cams as per MK's post.. I guess it's a system-wide problem.

Lava flow or vent? Looking closely in on the Poro cam there is an area glowing to the SSW of the eruption..

Uh it might be the ash on the ground rolling around too. It would have a prismatic effect.
Anyone know what the winds are? The other day it did it and I caught it from a different angle and for a brief moment the sun was doing the same thing...different color though.

I think the problem with the cams is that they are pixiling out much like satillite TV does in bad weather. At least that is what it looks like to me. At least we can see something that is going on. I guess it just makes it more interesting.

I have been gone all day and I took a break, too. I have a hard time keeping up with everything!

Erik, are you going to mention anything else that is going on besides Eyjaf and Gaua in Vanuatu?

Boris, is there anything going on with Etna yet?

I appologize if I am asking too many questions right now. Just behind the 8 ball. :-}

@Lurking,

Here is the other data you need to know to figure out the relationship between tidal stress and earthquakes. There are three styles of faults, pull-apart faults, push-together faults, and sliding-past faults. The forces on a pull-apart are tensional, and oriented at right angles to the line of the fault. The forces on a push-toghether fault are compressional and oriented at right angles to the fault. The forces on a slide-past fault are parallel with the fault, pushing in opposite directions on each side.

Now faults can be oriented in any direction, so you have to consider the orientation of the force on the fault with the orientation of the tidal forces.
THe San Andreas fault is a slide-past fault, with the coast side sliding north-northwest and the continent side more or less holding still. A tidal force directly overhead doesn't favor one side or another. But a strong tidal force oriented either east or west would reduce the amount of squeezing a tiny bit at dawn or dusk. So this fault would be most affected by a full moon at dawn/dusk.
The Sierra Madre fault is a push-together fault. The main force is north-south compression with a little left twist. Historically it tends to fail in the morning when the tidal force is normal to the main compressive force axis.

You have to account for both the orientation in 3-d of the 'static' geologic forces and add them to the the 'dynamic' tidal forces to work out what angle the tidal force needs to be at to push the fault to failure.

So I think a lot of the scatter you see is a function of the combination of the geologic force vector (actually tensor) with the tidal tensor. Also just randomness.

I'm with Diane. Been, literally , out of it all day. also have Diane's question.

227: ah, so Lurking needs to sort his EQ data by type fault motion and generate new stats, sort, then plot the relationship (percent change (over average) vs separation angle.

Mother nature strikes back i guess

Twilight on the cams now. :)

A good caricature of the eruption (Tuesday, April 20, 2010). The link brings you to today's cartoon, then you have to click on April 20, 2010:

http://www.montrealgazette.com/opinion/editorial-cartoons/index.html,

At least one engine manufacturer, to my knowledge, has finally released information on what they believe to be an absolute maximum mass loading which their engines may tolerate for the typical duration of a flight (whether or not the engines can operate all flights in this condition is not clear to me yet). Congratulations to the New Zealanders for obtaining information which the rest of us have been demanding for almost 30 years. However, given what the manufacturer declared and what happened in Europe, the London VAAC made the right call - don't fly. Anyone who says otherwise and spouts their pseudoscientific 'test flight' should be ridiculed in public. There is absolutely no doubt that the particulate mass loading in Europe was well in excess of what the manufacturer believes is tolerable. Even in milder conditions which would meet the manufacturer's declared limits, aircraft still need to be able to (1) measure the amount of sand in the air and (2) determine how the amount varies along the immediate flight path.

I wouldn't blame everything on the cams re colours, it could be explained by fractionation or a new source of magma. Bowens reaction series is the place to begin looking.
Think you will need a real vulcanologist with access to real data to explain it though.
Confuses me though as it looks like Na, K and Mg were coming up before and I would have thought they would have been some of the first to go.
Again usual disclaimer, just throwing ideas out there and have no real idea what I am talking about ;)

@ems #12: I doubt you'll get any data from the fools who ordered flights so they can claim that it is safe to fly. First of all, the inspection tools you will need for a thorough assessment are not likely to be available at an airport's maintenance facilities - you need to remove an engine and send it back to the manufacturer. On top of that, do you think they will release information that makes them look the fools that they are?

Isn't the fundamental problem with ash that it is assumed it will be nice and homogenous, that is mixed evenly across the sky. Where as in reality I would imagine that there will be varying degrees of density across the whole of Europe at the moment.
And as others have mentioned that is hardly going to be static.
So some flights will be fine, some won't be. To get highly scientific and use the latest research and technical jargon, I think it is referred to as...On a wing and a prayer...

Mad...All well and good but that is not an approved limitation. We would need one that all could fly in. Then how to detect the particles and determine size uniformly. No Passer has this one down cold. On board detection and 180 the hell outta there which like hail isnt generally possible.

So the manufacturer came up with a limitation? Anyone seen my P3 valve? Or the air data computer? All of which would and will have to come up with some sort of limit and it can tell you that is much more sensitive than the engines. As said, they run the throttles and trimmers, wrong info and you could zip through the sound barrier in about 15 seconds. It takes about that time to spool it up and the same to spool it down. For an aircraft cranking along at altitude at .83 to .87 Mach its like hitting the accelerator for a second in your car. Sudden burst and then the wings or tail come off. Or my fave... the T-top conversion as the airflow through the center section top crumples and pulls away.

If you have figured out that I am pissed off then good,else this is the official notification.

But the real deal is this. They think they are flying along safely. They arent. They will cite every occurrence of a safe landing, and minimize every one of them that isnt. Its not scientific, nor is the manufacturers report. It only notes that anything beyond the size noted "may have a detrimental effect on the operation of the engine and result in a loss of power"

If you have a bit of time to read and then note the distance at which the B747 was almost downed a few years ago you can see why I am so royally stinking pissed off. This may not be the volcano that does it, but sure as I see the sunrise each day this is going to get someone killed later, or at the least so scared that they could watch every episode of Lost and still not feel any better.

http://www.caem.wmo.int/moodle/file.php?file=/1/AFH_VA_26May20081.pdf

What will confuse the public is this: the skies appeared to be clear, thanks to the high pressure center that revolved and spread slowly. Adiabatic heating dropped humidity and caused rapid subsidence, pulling large ash particles down, but allowing small particles with highly charged surfaces to rise with the fair weather current flux increase. You also have turbulence and terrain effected currents that complicate air dispersal patterns, and where there are interactions with polar flows, there is also clouding, and rain.

Two other complications in observing and modeling ash plume mixing, dispersal and deposition: pollution aerosols that can form and concentrate over the Europe that can co-mingle with ash. It tends to be worst in low lying that collect vehicle and industrial emissions, filling bowl-like coastal areas (where our unfortunate Frankill resides) that are prone to inversions.

The second complication is Saharan dust carriage and deposition, which has become a near year-round source of light scattering over Europe, with strong winds driving it as far north as Scandinavia.

Throw into the mix the idiot farmers who are busily burning large swaths of fields for summer planting, and you have a very complex, messy situation in terms of figuring out which aerosol type is present at critical density within a particular vertical and horizontal location grid.

Agricultural fires are presently causing considerable smoke haze in the eastern and plains states of the US and Canada.

Looking at the Poro cam lost alot of the glacier tongue last night. There also seems that some big pieces of ice have slid in the forefront of the pic on the Vala cam

Tremors seem to be picking up a bit too.

Looks like the dragon is in an angry mood this morning.

@Diane #226, Etna is currently apparently quiet. There's a lot of evidence that it's not far from erupting but no activity at the surface, probably a flank eruption will occur within weeks to max a few months.

Re the triggering of eruptions and earthquakes by moon phases and planetary constellations. There has been research on this since many many decades. Never ever has a clear correlation been found. That's mostly due to the fact that, let's not forget this, volcanic eruptions and earthquakes are capable of happening all by themselves. The amounts of energy involved in magma movement and eruption (like magmatic pressure) are millions of times superior to gravitational forces exerted by the moon and planetary constellations. So, maybe such gravitational forces can accelerate things by a very short time - only that this makes no difference to us, because the volcano would have erupted anyway. If you look at our volcano here, Eyjafjallajökull, a lot of people have wondered if this was related to the Haiti, Chile, and Tibet earthquakes this year. But in reality the volcano has been preparing this eruption since at least 1994 when the first seismic unrest was recorded.

Re the colors on the webcams, be assured they've been artifacts. Incandescent magma is always ranging from yellow over orange to red, no exceptions. If the colors on the webcams took on more "psychedelic" hues, that was due to digital problems; when coming back to watch the webcams after a deep sleep this night, I saw that there were problems with a number of pixels, creating square- and rectangle-like features in the images, often right in the location where the glow was visible.

I don't think she's angry yet..she is just giving us a little taste of her temper a pre-show if you will she seems to have something in store for us...

Fissure to the forefront of the main crater eruption site is active as of a few minutes ago, which may be the 'twin' plume effect mentioned yesterday (I did not see it as I had trouble dialing into all 3 MILA webcams at their height of user demand).

Major uptick in plume emissions visible at daybreak. Not much of tremor signature yet, zero EQ activity.

Mild image breakup, possibly from high user demand, vala webcam.

Valahnuk cam's gone pitch black - maybe it crashed due to too many ppl trying to see it or a tech glitch? There was a lot pixelation in the Valahnuk cam at times in the sky above the volcano, not just the lava glow.

Renee maybe she just got up on the wrong side of the caldera;)

What do the green lines mean on Jon's helicorders?

Renee could you please give me the address for Jon's helicorders?

For those of you with Google Earth, I created a file containing locations of the various webcams around Eyjafjallajökull. I also added links to overlay 2 GeoEye satellite images and 7 NASA MODIS images.

You can grab a copy of the kmz file here:
http://panojoe.urmos.net/files/Eyjafjallajokull%202010%20Eruption.kmz

In the Google Earth window, click on any camera icon for an info bubble containing links that will take you to the web page of the camera at that location. You can also double-click on the camera icon to go to a Google Earth view that approximates the webcam scene.

The GeoEye image from the 17th is well worth a look. It is at 1m resolution, so you can see a lot of detail; well, at least for the areas not hidden by the eruption column. For example, you can see a small airplane directly over the meltwater river channel where it exits through the Gigjökull terminal moraine.

Please let me know if I need to better position any of the camera locations or adjust the view to better agree with the webcam. I think my Mýrdalsjökull view is a bit off because I have not seen a clear view from there.

Ideally, it would be nice to incude each of the webcams directly as properly oriented and sized overlays within Google Earth.

For me, the geographic context makes the webcam views much more understandable.

Nicely said I see you have a similar sense of humor...that could be dangerous

Here is the link for the helicordershttp://www.simnet.is/jonfr500/earthquake/tremoren.htm

@Passerby [229]

"...ah, so Lurking needs to sort his EQ data by type fault motion and generate new stats, sort, then plot the relationship (percent change (over average) vs separation angle."

That's actually not a bad idea. You mind pointing out where that info is located in this data field?

PDE 2004 12 26 005853.45 3.30 95.98 30 9.0 MwHRV 9CM STS...M

Short of 'assuming' that the quakes at each fault location are the same, looking them up at each site becomes problematic. I'm already to the point that to look at this semi-lunatic theory any further is going to require that I dump all the data into a database server. I did that a few years ago with the Hurricane data so it's not an impossible task... just a pain in the arse for a hobby sort of activity. Excel has the ability to connect to the server, and doing anything more than 5 or 6 open spreadsheets in order to combine the data is taxing for the machine. One sequence alone took 20 minutes to look up.

Remember, this is a wild arsed theory that is probably a dead end anyway. Why? It can't really be tested. If you predict that there could be a quake on so and so date... and there is one, it still doesn't mean the idea is sound since in all likelihood, there would have been a quake somewhere on the Earth anyway.

What I take from it is that this connection seems to exist, and is just plain odd.

Besides... there are people out there with better access to data who get paid to look at odd stuff like this anyway.

Daniel Thanks!

Renee which green lines the ones at the bottom of Hekla?

@renee and others, A long time ago I put a explanation on top of the web page with the helicorders what the lines means. I am getting a little bit annoyed of people not reading what it says on my web page, since I put it in a plain sight on the web page. I am all good with helping people to understand. But I need to draw a line somewhere in the sand.

Here it is the explanation of my helicorder plot, as it on my web page.

Explanation of the tremor plot

Green line = no data recorded / coming in
Black line = normal data recored
Red line = local earthquake recoreded. Noise sometimes creates red spikes.
Orange line = Telesismic event has been detected.

/ Annoyed mode off.

Green line = no data recorded / coming in

Jon the human mind is a funny thing....we often don't see what is actually in plain sight;)

Looks like there is a posting delay with the Vodafone pics on Picasa? It does look like the glacier has slumped down in places, but that may be only the difference in the angle of view and light source between the Mila cam and the Vodafone shots from yesterday.

Jon I am sorry to have upset you... and thank-you Randall I think I shall stop posting for a bit until I learn the ropes a little better.

@Scarlet Regarding Weather models. These are excellent in accuracy in the short and towards medium term but of no use in the long term. You should never look at just the one model though, but take the average to some extent of all the various models - UKMet, ECM, MRF etc. Short term forecasting is really pretty good. Ash forecasts after all are short term.

Adding your own personal experiences is always helpful too and knowing that some models exagerate the rarer events, such as northerly cold flows etc is key to gaining an accurate forecast.

I think some forecasters depend too much on the models and sometimes dismiss their own experience. One has to strike a balance here, but it is very difficult.

Of course when it comes down to safety , it should ALWAYS come first, and any organisation that takes risks on lives should be up for manslaughter, especially when we know the consequences of small amounts of ash. The arrogance of the airlines is dire.

On a weather point. The plume should move more northward gradually away from UK airspace and flow westward in short term. Gradually being fed back on westerlies. In fact smaller particles could ascend in the low pressure systems that will dominate, unless washed out by rain. Depends on the amount and height/ type of ash. In the medium term towards end of the month and beginning of next , there is a tendency for north westerlies to develop again over Europe , just like recently.

If a volcano in Iceland erupts big time on the 27th, then the weather patterns (65-70% chance of this, becomes higher as time progresses but quite consistent at the moment) should be ideal for disrupting Air space again. ARE THEY PLANNING FOR THIS! Or continuing operation cover up and risk strategy where finance comes before lives?

Jonathan Witty - Life long Amateur Meteorologist
Used to run theweathernews.com, IRC channel and Metnet BBS 1986 to 1995 (those were the days! (LONG GONE)Anyone remember?

Man, I just don't understand what that red line thing-a-ma-bob is on the Helicorder page. I've looked all over and can't find any info on what it means. Any body have an idea?

(/kidding) It's a great page.

Jonathan Witty....planning....no. Money before lives....yes.

"For it tis' the doom of men that they forget" ;)

@Randall Nix, I don't blame people. I blame the education system (really!). But that is a discussion for a different place and time.

Another rant. Maybe there is just too much air travel and too many airlines. It becomes irresponsible, Most if it is for leisure and the individual countries maybe should promote the tourism in their own countries. Every country has a lot to offer and encouraging walking, cycling etc etc would benefit local sectors of the economy and many other benefits. Anyway just to note I do not have much sympathy on the many thousands that were stranded. It was their choice to go to those exotic places as it would be my choice to cycle round Scandinavia as I once did. My bicycle axle broke, I would not expect to be paid to be returned back, nice if someone did! But WHY? I would also not expect my safety to be compromised in any way by people in business - eg: airlines, ferries , buses etc..

252. The info you need for the *fault* is not in the fields you downloaded for the *earthquake*. The easiest thing to do is to look for the historic moment tensors for earthquakes along a fault...
http://www.data.scec.org/MomentTensor/solutions/web_10629477/ci10629477… for a random example. The beachball diagram shows the exact orientation of the stress on the fault. Then you do that for every fault you are interested in, which is a monumental job. Then sort the moment tensors into groups of similar orientation, and work out the tidal triggering direction.

Then go back through the historic record and see how often the groups actually are triggered by the tidal force.

I have no doubt that what you are observing is a real factor in when an earthquake triggers, but that it's only the final event in a long process of getting the fault to the breaking point.

Another approach, the one I use, is just to enjoy the show: I check the USGS California-Nevada page every day. I watch the time and moon phase, and I have observed that there are definite patterns in the small quakes by moon phase, time of day and phase angle , with strike-slip faults ( which mostly trend north-northwest) occurring on different combinations of time and moon phases than on compressional faults (mostly east-west). The recent quake in Baja was interesting because it happened in midafternoon on a pull-apart fault, which puts the tidal pull 45 deg off the horizon. I think time of day is important, because the tidal pull on the horizon is acting in a different direction from the same tidal pull overhead.

So my question is, what is the principal force direction for volcanic eruptions? Is it upwards directed? Is there a relationship between where fissures happen and moon angle/phase? Do volcanoes erupt more strongly at night, noon, or daybreak? Does a full moon overhead trigger eruptions?

re: Lurking

What is your statistical significance of your data peaks? (ie, is p less than .05?)

wetDirt Boris can tell you but I would think the force direction of a volcano is generally up;)

@ Scarlet Pumpernickel The Met office is no longer doing those long term forecasts on the web site. They always did say there was a very high degree of uncertainty. Unfortnately but predictably the media states a risk as certainty and overplayed it. I agree that long term forecasting is not really possible as there are just too many variables. The overall general pressure pattern can be done to some extent though, but even here so many difficulties.

http://www.leif.org/research/IAGA2008LS-final.pdf Some more info on Solar energy. It does look like more research should be done since if the solar activity can effect the magnetosphere and the ionosphere and these are both originating inside the earth could these events be stimulating things, maybe there is even a delayed reaction?

Watch the video, it's hard to think these events would have no effect on the core or magma under the ground?

http://www.suntrek.org/images/movies/SOHO5_CME_ANIM_EARTH.mpg

FYI Claude Debussy "La chute de la maison Usher" sounds pretty good with the volcano;)

@lifeblack [265]

"What is your statistical significance of your data peaks? (ie, is p less than .05?)"

Thats the part that has me weirded out. I'm getting p values of 1 for the spikes (such as the ones above). I figured that as I added more years into the set the vagaries would eventually work their way out of the system, but each time I add a set the spikes get tighter and more apparent. I was hoping to get to a ten year set, but then I ran into the clumsiness of doing it via linked spreadsheets. I'm not stats guy, so I'm at the point of wondering if I'm just barking at the moon. (pun intended)

Ave - 1.53%
SD - 0.198879425
Skew - 0.468707403

Scarlet - I have little knowledge on solar,lunar, planetary, universe! effects on quakes and volcanoes - and weather, but I suspect there could well be a substantial link. Even if small , it could be enough to tip the balance. Sounds plausible anyway and I am sure there are many theories being researched.

The changes in the lunar and solar gravitational pull has a big impact on the planet as a whole, as shown by the ocean tides or the tidal flexing of the crust as a whole. But these effects cannot be felt locally, as the difference in gravitational pull between two points a few dozen kilometers apart is negligable. I believe wind and rain are stronger local forces than tides (as can easily be seen on Jon's helicorders). Volcanic eruptions are pretty much local events (from a gelogical point of view, their meteorological, hydraulic and climatic results can of course be quite far-reaching).

In short: Even though the tidal forces are huge, the differential in this force across the dimensions of a volcanic system are negligable.

btw: yesterday's timelapse is in the process of being uploaded. It is a 12 frames per minute instead of 1 frame per minute animation, so much higher temporal resolution.

Good morning!

A tidbit I just saw on mbl.is:

North Korea, Svalbard, Somalia and West Sahara: These are the only countries/areas in the world where noone has been watching the eruption via the Mila web cams!

On the subject of soundtracks, Angela posted a video link awhile ago that paired Iceland's Sigur Rós with some shaky aerial volcano footage. Doesn't that sound like a cliché? But no, it was just perfect. I thought it was worth reposting even though it's on Facebook:

http://www.facebook.com/video/video.php?v=1395588323904

I am in heaven. This site has produced more sensible discussion threads then any news article I have read so far.

In one way its very complex when allot of information is shared but also shows an interest to:

1. Get a clear and reaslitic overview of this event
2. Get an assumption of the aftermaths (scientific: eruption related and its effects on public (people, land and economics)

I have written a few comments in other blog's mentioning perhaps the same story again and again (how we actually handle nature versa global econonomics, governance dealing with this particualr matter etc)although the key questions are:

1. How should we handle this matter in future similar cases
2. Who would dare to put science as a clear decision maker in front of a very sensitive economic setup ( e.g. halt of aviation)

I suppose the matter of taking risks is covering the subject:

How much calculated risk will be taken to keep the economy alive in such circumstances

I have to admit that I am happy to see nature rule. To see the fascination of its beauty and destruction if taken place. How small we actually are. This again proves my point that if we ever move this discussion to Global climate handling, how do we relate to ease the use of CO2 etc if we cannot handle a strong and sensible dealing of a situation where nature is effecting our climate (eruptions) and directly our economy. How do we move this to a positive pro-active workforce between scientists and business?

I hope this all ends up (even though I see the airlines being less cooperative in a next eruption) that scientists like many of you will get a strong funding for your work. That a new governance is created between facts and data by the work of scientists and logically advised and put in perspective to the commercial end.

The biggest crime would be not to take you guys seriously and let the commercial entities overrule in the future. Its a political game per country perhaps, but also a great opportunity to start working internationally.

We actually need a UN for climate and disasters management. It would then, if anything like that occurs, be interesting who the main players in such establishment would be.

My 10 min of thoughts. Again thanks for this Erik.

Cheers
Eric

@271 Jonathan Check out http://www.geo.mtu.edu/volcanoes/fuego/tide.html

Was this a coincidence? http://www.eso.org/public/news/eso0123/

@ Scarlet Pumpernickel / 271

Io is a very different scenario, there tidal flexing is THE source of heat driving the volcanism. The tidal bulge is about 100m high on Io's crust. Jupiter is muuuuch bigger than our moon and Io is much smaller than earth but the distance is quite similar to the one between Earth and the moon. Also the forced orbital eccentricity introduced by the orbital resonance with Europe and Ganymede is missing from the Earth-Moon system.

See http://en.wikipedia.org/wiki/Io_(moon)#Tidal_heating for a little more information.

276 Scarlet - Think I will keep an open mind on this. To me it makes sense but then 272 makes sense as well. Let's face it, the whole world and universe is interactive. Some to a lesser or greater degree and dependent on other events working multi laterally.

@Phillip What about orbital resonance are other bodies such as Venus/Mars too far to line up with the moon and the sun ;)

http://www.youtube.com/watch?v=9mvBiCxLN8Y

The moon's gravity does make the earth bulge out a bit. The sun on the other hand has 40% less effect then the moon, so over day and night there is a bit of pressure on the earth/magma? Is this why sometimes night eruptions are bigger/different?

On the side facing the Moon, you are as much as 1/60th closer to the Moon than if you were in the middle of the Earth, producing a force which is 1/30th larger than average. On the side away from the Moon, you are as much as 1/60th further away from the Moon than if you were in the middle of the Earth, producing a force which is 1/30th smaller than average.
SO, on the near side, you are pulled by a force which is 1/300,000th of your weight, which moves you around the barycenter every month, AND by an additional force equal to 1/30th of this, or 1/10,000,000th of your weight, which tends to pull you away from the rest of the Earth. And on the far side, you are pulled on this much less than the rest of the Earth, which tends to pull the rest of the Earth away from you.
KEEP IN MIND that at the Equator, where things seem to weigh 1/3% less than at the Poles because of the Coriolis effect of the Earth's rotation, the Earth bulges out by about 1/3%. In other words, it bulges out by a fraction of its radius approximately equal to the apparent reduction in weight. IF THE SAME THING happened with the differential force = tidal force of the Moon, the 1/10,000,000th difference in force on different parts of the Earth would make various parts of the Earth deviate from their normal position by 1/10,000,000th of the radius of the Earth, which is about half a meter, or 1 1/2 feet.

http://vulcan.wr.usgs.gov/Outreach/AboutVolcanoes/do_tides_affect_volca…

At 0903 UTC very definitely two plumes in the Múlakot webcam pic.

Oooops! Can't do 'rithmetic any more... 0803 UTC.

@R. de Haan

I'm afraid you're incorrect about the ash sampling in the UK. NERC have run several flights to sample ash:

Thurs 15th
Sun 18th
Mon 19th
Wed 21st and onwards

www.nerc.ac.uk/press/releases/2010/17-icelandvolcano.asp
news.bbc.co.uk/1/hi/england/wiltshire/8628028.stm
www.nerc.ac.uk/press/releases/2010/18-volcanicplume.asp

Blue skies over Europe has nothing to do with ash levels.

The commercial "test flights" were more PR stunts than useful scientific endeavours as unless they had instrumentation on board to see whether they actually flew through ash and how much they flew through, they cannot actually tell us much. I've seen no hard data come out of them, so they really don't see what point they had other than propaganda.

@scarlet

I can tell you don't trust the Met Office, and that's your prerogative of course. But if you're doing to try to rubbish them, please do some with some facts regarding their ash forecast, instead of attacking long-range forecasts which pretty much everyone knows are difficult and inaccurate.

Blanket skepticism is as daft as blanket belief. Please try to look beyond the propaganda (such as the nonsense spouted by many Telegraph 'journalists') and judge the situation on the facts.

Another point worth considering is that the climate is not the same as weather. Even if models for climate have problems, that doesn't mean that models for weather are similarly afflicted - they are different models, are easier to test (if the weather in 3 days isn't what you thought it was going to be, you can go back and look at your parameters).

For anyone interested, these two pieces from the Guardian on how the ash cloud is being monitored and the end of the flight ban are interesting:

www.guardian.co.uk/world/2010/apr/20/ash-cloud-aviation-industry-flying…
www.guardian.co.uk/uk/2010/apr/21/airlines-battle-skies

As well as the NERC flights, monitoring is being done by satellite (Meteosat-9), weather balloons, and 30 laser monitors usually used to monitor cloud cover. All that data feeds back into the Met Office model.

I wish that the Met Office were more open with the data they are collecting, but it's their prerogative to keep their info to themselves. But we can't pretend that the Met Office is just pulling their forecasts out of thin air (no pun intended).

@ Scarlet Pumpernickel

I don't think there are orbital resonances between Venus, Earth and Mars. Jupiter would be a far bigger influence but I never read about an Earth-Jupiter resonance. (Been reading astronomy books and magazines for about 25 years now)

from your link: "Although this is a fascinating correlation, there are just too many tidal maximums and too many volcanoes to base predictions on tidal cycle alone. In the Hawai'i example of 52 eruptions since January 1832, there have been nearly 3,900 tidal maximums, of which roughly 3,850 of them went by without causing an eruption. Statistically, this is about a one percent chance that any tidal maximum will affect the start of an eruption."

And I think you mean centrifugal force instead of coriolis force when writing about the apparent weight reduction at the equator.

And yes the Earth's crust has a tidal bulge, but it is very small compared to e.g. Io.

And there might be statistics that link volcanoes and tides, but tidal forces are not what creates volcanoes, they doesn't cause eruptions and you cannot use tides to predict the behaviour of a volcano.

And finally, it is Philipp not Phillip. :-)

@Suw we shouldn't keep talking about the weather, my problem is that when it's warm then it's climate, when it's cold it's weather. An uptrend on a chart can't always be just trended upwards, that mistake was made in the 1970s when they thought one dip suddenly produce an ice age. The weather/climate changes all the time. There is nothing really strange about current weather, if we look at the last 1000 years alone we've seen wilder things happen over and over, even in the last 50-60 years in the UK. Also the strange ads like this http://www.youtube.com/watch?v=0dOfBEm5DZU&feature=related feature prominently in UK public information are quiet odd. I'd be more concerned if the planet was cooling, 1350-1800 was not a very nice place to be, especially europe, the plaque, constant famine, terrible swinging weather from freezing raining times to sudden heat waves in summer swinging from one direction to other.

This was an interesting find in Alaska http://www.blm.gov/pgdata/etc/medialib/blm/ak/aktest/frontiers.Par.8329…

I hope more funding is given to Volcanologists and MET for monitoring ash in the region, so we know where the ash is, since really at present it is hard to tell where it is and it's thickness. It could be good if they take it from the climate budget, as too much money is being concentrated in climatology and it should be given back to the earth scientists as they are scientists I respect highly.

@Philipp Maybe it correlates not with individual volcanoes then but periods of overall increases in global activity?

Though in that example they are talking about not a stratovolcano (where pressure builds up), but the Hawaii shield volcano which is almost in constant eruption from the mantle plume? Maybe things are different for bottled up volcanoes rather then the big shield ones?

http://it.tinypic.com/r/34xnds8/5

yesterday's timelapse is ready: http://www.youtube.com/watch?v=9-4CkL-csLI

the HD version is still in processing, but should also become available in a few minutes.

http://www.youtube.com/watch?v=xC5KOBMKwnQ

Has anyone seen this doco "Drain the Ocean" From National Geographic. Was on the other day pretty amazing, especially the section on the ocean ridges.

http://www.youtube.com/watch?v=7HdO6kavL2k&feature=related

Sorry this is the trailer for the "Drain the Ocean"

It is all so complex that it is impossible for us to understand everything; ergo we understand nothing.

http://pale.nsdl.org/cac/global_warming/Arrhenius_1896.pdf

@scarlet

I'm unsure what point you're trying to make. Climate has nothing to do with this volcano or its ash cloud at the moment, although if a much more serious eruption occurs, it might be affected. It's weather that we're currently interested in.

Whilst some people may misuse the terms climate and weather in other discussions, in this discussion it's very clear that weather, i.e. what the wind is doing, whether it's going to rain, is what is important rather than long-term averages and patterns.

How terms are used in the broader climate change debate is irrelevant.

Philipp -- fantastic video!

I know the MÃla-people have received countless emails, many from teachers in the US who have been using the streaming videos of Eyjafjallajökull in the classroom, for various teaching purposes. Lets hope teachers will find your videos on You Tube, I'm sure even students with ADD would quiet down and watch!

An earlier video of yours (20th or 21st?) was actually quite comical. The white clouds were flying from left to right and the dark ash plume, at higher altitude, was going in the opposite direction. It looked like a dark little demon, angrily fighting all those white missives from the north that just kept coming and coming and coming!

How to know from tremor that something new is going to happen? Are there any signs?
Anything new from Katla?

Re planetary influence - At their closest, Jupiter exerts 1/84th, Mars 1/1250th, Venus 1/125th the gravitational pull of the Moon on Earth.

Re Solar Wind - If it had a direct effect on volcanism, Arctic and Antarctic volcanoes would erupt more frequently than equatorial ones. Do they? Cf areas where Aurora Borealis/Australis is visble! (That's where the Solar Wind, ionised hydrogen and helium nuclei + electrons, gets through the Van Allen belts and interacts with the Earth's atmosphere.) Indirect effect - There should be an observable correlation between the number of sunspots and frequencies of eruptions. No such correlation has been noted.

@Matic: Correct me if Im wrong here anyone!!

But as far as i understand the tremors are an indication that something is moving. I.e for example magma moving through conduits underground and so on.

Stronger or increasing harmonic tremors could indicate magma rising up to the surface. But one thing that I have heard is that harmonic tremors within a volcanic system is a sure sign of impending eruption in some way.

No signs of unrest at Katla as far as i can see. Some inflation but i guess that is only normal throughout the dormant periods of a volcano.

I presume that is ash being whipped up by the wind on the right hand flank of the glacier on the Ãórólfsfelli cam. Looks a bit like steam but can't be surely.

@Henrik The solar wind causes aurora, but this is at via the back part of the earth, the solar wind also changes the shape of the field where it first hits it. Does this make it like a magnet, and you push another magnet near it and you move it? Does this cause anything to happen inside the core? A Danish study recently showed that space weather could effect the tropical rainfall, this is nowhere near the poles. http://dsc.discovery.com/news/2009/01/13/magnetic-field-climate.html

http://www.space.com/scienceastronomy/earth_magnetic_031212.html

There has also been a loss in the earth's magnetic field over the last 150 years, suggesting that something is changing below our feet...

On the Poro cam a little steamplume was coming out of the ice tongue on the right hand side.
it has stopped now.
anybody else saw this?

Scarlet! Look up Faraday's cage! ;) As for the (apparent) loss in strength of the Earth's magnetic field, it does fluctuate and even reverses in polarity occasionally (on a geologic, not human timescale). I'm sure there are several professionals here who can give you, not only a proper run-down, but also far more accurate answers!

Some great pics of Iceland Volcano and the Aurora out

http://www.dailymail.co.uk/news/worldnews/article-1268225/Iceland-volca…

@Scarlet Pumpernickel:

"There has also been a loss in the earth's magnetic field over the last 150 years, suggesting that something is changing below our feet..."

Couldnt that be part of the ever changing pole switch? I mean the earth switches poles every now and then and an effect of that would be the weakening of the field. And as far as i know the poles are switching as we speak just that it takes hundreds or thousands of years to complete a pole reversal.

Frankill, I saw that too. It looked as if it may have been caused by hot water running down the established channels on that side of the glacier.

However, look at the left-hand side! There are a couple of dark spots that eject white steam. It looks as if a volcanic bomb or suchlike had landed there and was busily melting a hole in the otherwise white hillside. One of them has even left a dark streak across the snow.

http://www.dailymail.co.uk/debate/columnists/article-1267904/Iceland-vo… Pretty funny article :P

@Daniel well according to the article at @296 if they draw a straight line on the chart for pole reversal it's going to happen in 1500-2000 years lol. But I don't think so. I think its controversial when it will happen since it doesn't happen very often. Also I think I've read that some say it can happen pretty quickly, while others say it happens over a very long time period. Does this mean that the whole core is slowly rotating?

@Henrik, Yeah I know about the cage, that's where you put your harddrive to protect it from the next big solar flare :P

Re planetary influence(earth) - As well as tidal shifts is there evidence of links between the changing water mass of the sea on oceanic plates effecting volcanism, esp on the mid atlantic ridge (squeezing the toothpaste style). Im thinking a few degrees shift in localised sea temperatures alters the density of the water and the mass loadings on the sea floor quite a bit. Allowing the plates to either spring up and apart or press down and increase pressure.

With magentic pole break down and reversal cycles(http://www.physorg.com/news159704651.html) we know about it because of paleomagnetic records in volcanic rock, and the main changes are inner core related but just wondering if there is any link in the record of how this effects volcanic activity levels, directly or possibly by effects on the magnetic compounds in the crust and mantle?

http://earth-of-fire.over-blog.com/ext/http://www.csiro.au/files/mediaR…

Maybe this will start selling now? I?s it being used already

@Frankill and Henrik. I think these steam plumes are what i was refering to in #295. I assumed that it was ash that had fallen overnight being whipped up by the wind. I does look alot like steam though. Has anyone found temperature monitoring data for the Markarfljót river? That could tell us if the water flowing down is hot enough to produce steam.

@Henrik I saw that dark streak also. But i have a slow
refresh rate and that streak appeared in a flash second.
ps. i did not see anything "landing"

@Matt P I would be interesting if earthquakes/volcanism increased or decreased just before or during a pole shift. Not that I'm saying it's happening now.

Also whats weird is the pole up at the north or south pole moves all the time, does this mean that the core is spinning a bit causing the pole to shift, how does the whole thing flip over completely, it really does not make sense. I think working this out will really give us some understanding of core. We still don't know that much as we've only been down to 6km, where we found Hydogen gas and mud?? http://en.wikipedia.org/wiki/Kola_Superdeep_Borehole

Hendrik take a look at the top black spot on the tongue!!

multiple steam plumes to the left an right of the tongue.
The middel black spot however is a grey-ish plume....

Henrik, Frankill:

Which web cam are you looking at?

@Jamie Z It steam coming up. We will just have to wait and see. ;)
The middle plume looks like it was a ash plume. But could be like you said.

Thorolfsfelli, Anna!

I'm looking at the Vodafone picture.

Seems to me it's mist you are talking about (Frankill), from the splash when meltwater falls from the opening of the crevice.

Henrik, is the Vodofone cam still unavailable to people outside Iceland?

The effect I am refering to is very evident on these vodafone cam shots 38 (around 9.40), 41 and 42. Near the top of the mountain, right side of the glacier.

http://picasaweb.google.com/102175391233488315229/EyjafjallajokullVolca…

It appears that a French reporter (presently in Iceland for TF1) has mastered the pronunciation of "Eyjafjallajökull". I'm sure a lot of people are going to be buying him drinks at the bar tonight.

http://www.mbl.is/mm/frettir/innlent/2010/04/23/kann_ad_segja_eyjafjall…

Anna! On the Thorolfsfelli cam the two points I refer to are located as follows:

* On the ridge just to the left of the crater is what looks like a dark knob or boulder that has smoke/steam coming from it.
* To the extreme left, at the bottom of the snow-covered glacier, is a dark depression. Just above it to the right is a dark spot. From that spot a steam curtain extends to the right and also a dark streak that runs uphill from it.

The position Frankill describes, I believe, is one of the areas where the glacier has caved in and warm water running below is emitting steam. To confuse matters, ash from the plume lands on the snow so there are small emissions of steam from many places.

Hope this description is sufficiently clear!

Looks like a lot of ash has been dumped on the volcano flank facing the Vodafone webcam, look how it changes from white to dark grey over the morning here:

http://picasaweb.google.com/102175391233488315229/EyjafjallajokullVolca…

It looks like it's already being stirred up by the wind.

Thanks Hendrik! you just saved me a lot of typing;)
also

I will try to describe the other location also.
starting from the ice tongue, to the right there is a piece (rock or ice) in a 45 degree angele.
More to the right is a big "ridge"? follow that ridge to the top. there it originated from.
It is at thesame hight as the first circular black spot on the ice tongue (half way up) you would see ,climbing up the tongue.
sorry for the typo's. now it seems mist that is blowing but if you see longer then once and a while
a clear vissible white steam plumes comes out.

@ JamieZ: is this the photo you meant? There's lots of small streaks of steam crossing the mountain just under where the plume starts.
http://extras.vodafone.is/trailers/fimmvorduhals/mx10-4-235-80/2010/04/…

Check also this photo:
http://extras.vodafone.is/trailers/fimmvorduhals/mx10-4-235-80/2010/04/…

@Scarlet I think they have a pretty good model of the mechanisms of mag pole shift/wander http://www.psc.edu/science/glatzmaier.html and they seem to align with theories on the innerards of the planet.
I was wondering what the restrictions are currently before, like we have progressively complex models for the weather we experience on the surface. If we could get to a forecast model for the inside of the planet - with global and regional 'climates' and localised anomolies, being able to predict magma movements/temps/composition before it breaks the surface.

That isn't steam - it's snow being blown along the ridges and off rocky outcrops.. you can clearly see the same happening from time to time on far left slopes.

Anna, Henrik - my take on the steaming you see is that hot ash falling from the plume is landing on snow and causing it to steam as it vapourises it. The ambient temperature on that glacier and the surrounding hills must be around or below freezing which would cause a lot of steam/vapour to be visible (like your breath on a cold day!). There are also some interesting cloud effects, possibly caused by the updraft created by the plume which could be sucking warmer, moist air from the valley up to lower temperatures above the glacier and snow-covered slopes, again causing vapour/cloud. This was quite visible in Phillip's movie of yesterday's Vodafone shots
http://www.youtube.com/watch?v=9-4CkL-csLI

Jamie Z #315:

Thanks for the pix. Seems to me (like Henrik said) that this is a deep and narrow crevice and there's hot meltwater running down there.

Frankill #319, I see what you mean.

@Scott #236: A prayer is about it. Since scientists (and some airlines) have been pestering airlines for reports on volcanic ash encounters (close to 30 years now), there have been about 200 incidents reported (and we know for a fact there are also many incidents not reported). Anyone who thinks they can look out the window and decide where it's safe to fly has never encountered volcanic ash before - do people really think that more than 200 pilots are so stupid they flew through an obvious hazard? In all cases the pilots did not believe there was anything unusual until it was too late; it is extremely fortunate that there has been no catastrophic loss of aircraft yet (though a number of aircraft have had to be scrapped in the worst cases and in other cases an expensive overhaul and engine replacement). Humans simply cannot judge the hazard by sight; we need to rely on instruments. Since these encounters are a very rare event (compared with total flights per year), there has been no great demand to do research and development of such instruments.

@Matt P Thanks pretty interesting article especially the animation http://www.psc.edu/research/graphics/gallery/CORRECTno_earth.mpg

That's why we can't predict volcanoes, we are totally blind. If we knew what was happening down below, we could tell everyone exactly what was happening. We can only see the pipes after the fact once the magma has left. And we will only know if a new volcano is coming from earth tremours, VLF is still not advanced yet.

http://www.vlf.it/mognaschi/TERREM3.html

Lava weather would be great :P

Henrik, 317

Thanks, your description is very clear.

Is there some kind of hot debris descending the slope to the left of the main plume on Thorolsf cam?

I wonder if there has been a lava flow down behind the slope we're seeing to the immediate left lip of the crater. There appears to be a separate plume coming from that area, often whiter (steam) than the main plume.

Is this ash falling? http://www.vedur.is/vedur/athuganir/vefmyndavelar/reykjavik/

Anne 324

Anne, the volcano has occasionally spewed out huge red-hot boulders, 100s of metres in the air, and they leave really big holes in the glacier where they land.

But the ash is quite cold when it lands on the glacier. So it's not ash that explains the tufts of steam (or snowdrift).

http://www.cosmosmagazine.com/news/1967/earths-poles-long-overdue-rever… More on pole reversal, coming soon 400,000 years late?

Ok. It seems I already got the answer: melting snow through the crevice, thank you.

Sorry. I realized it was just dirt on the camera.

The main plume gets darker and darker. And another dark strip of cloud to the left. Fascinating!

I dropped by the local grocer's this morning. There's a special on 'eruption and lava'. Gos (eruption) is slang for carbonated bevvies (coke, pepsi et al.) and Hraun (lava) is a crunchy biscuit bar covered with puffed rice and chocolate.

Sorry, again: but it looks like dark ash is being pushed towards the crevice. Like a small piroclastic. Just keep watching!

@SP: Please read this.

http://scienceblogs.com/highlyallochthonous/2009/02/is_the_earths_magne…

More disruption: http://news.bbc.co.uk/2/hi/uk_news/scotland/highlands_and_islands/86390…

@Scarlet - maybe in a few years we can use the earths magnetic field as a MRI scanner to get all the info (http://thefutureofthings.com/news/1067/first-low-intensity-mri-scan-of-…) Google earth with the inside filled in would be super cool :)

http://www.antya.com/wikisearch.php?article=y&s=Geomagnetism

Interesting article on Geomagnetism

Also magnetic storms can cause erosion and arcing in metal pipes http://www.astrosurf.com/luxorion/qsl-perturbation4.htm so why can't it effect a giant metallic core?

Or maybe these are just shadows playing tricks on me?

@M Randolph Kruger #237: The subject of instrumentation on passenger aircraft was brought up maybe 15 years ago in relation to the "no fly" zones. Due to various limitations, the location of the plume is estimated and then a fairly large area is drawn around it; the diversions can be very expensive due to the amount of fuel which may need to be put on board. The idea of the instrumentation was originally to allow pilots to identify the edge of the plume and perhaps take less of a diversion based on instrument readings rather than strictly following the (conservative) declared limits. Although you still have to load all that extra fuel on, you may at least be able to save some of it (though you might then have the problem of the wings icing up after you land - you just can't win). The instrumentation will also allow a pilot to detect a volcanic hazard even if no alerts have been posted yet, which is vital because there are many volcanoes around the Pacific which are a hazard to air traffic but are not monitored.

The attitude has always been "if we can detect ash there, just don't fly there"; what some airline officials in Europe are whining about now is being allowed to actually fly through the ash, not merely cut down on the diversion. Given the latest information from manufacturers, the original "don't fly where you can detect ash" still holds for all practical purposes - the figures quoted are really very very low.

At the moment the instruction to pilots is to use their own judgement to get out of a volcanic plume as quick as they can - which is pretty much turn around 180 and head back to a general area which you know was clear just a few moments ago and decide if you should divert to another airport. Yes, you cannot instantaneously get out, but there is no sense in holding your course. Unfortunately without instrumentation how do you really know you're clear of the hazard? So the instructions may not seem very sensible, but for lack of knowledge we can't offer anything better. If you happen to hit a very thin plume, you're lucky - if like Captain Moody you hit a moderately dense plume that's just tough luck - hoping for clearer skies at lower altitudes is the best you can do; attempting to turn around is not recommended.

@Gordys check out the link from the same article interesting picture with the field getting muddled up inside the conection area, the model also depends on the energy of the sun to keep it going. All of this powers the earth's tectonic plates which in turn power the volcanoes thru subduction zones and mantle plumes

http://scienceblogs.com/highlyallochthonous/2008/03/where_the_earths_ma…

#332 @Mattias: If you're thinking of the north-(norður-)pointing camera, I only recall seeing it with a yellowish tinge.

Jon #341

It seem Scotland wants to play it safe, they're clearly distrustful of the new criteria re. the danger of ash.

It's interesting to notice that GOLA gps station is reporting a very slight [upward] ground inflation for the fourth consecutive day:

http://hraun.vedur.is/ja/gps/predorb/golapred.html

This might be a new trend pointing to a new eruption phase as Jón FrÃmann hinted.

@ Renato and others, could be that a hot flow of material is falling into the top right depression. Making its way
through already made watertunnels. that would explain the steamplumes coming out in differant places.
I could be completely wrong also. :)

@348 ... smart move :)

Something is definitely coming downslope on Thoeorlf. Look at Hvlosvelli cam as well: two plumes?

frankill:
:) I understand. But I hadn't seen that before. Awesome!

people on the poro cam!

Some Trolls on the Ãórólfsfelli cam :)

Mask ball at Porosvelli. Are they partying?

@ Gordys # 340 and Chris (who sometimes appears here)

Brilliant article, just what I was looking for. In fact I was about to post a comment to this effect on his blog but had to burst out laughing at Chris's last post so I'll just say thanks here.

@ everyone else discussing tidal movements and (a few days ago) the impact of distant earthquakes:

I am trying to get a handle on this discussion and I am afraid the subtlety of it is beyond my grasp. Let me start with basics:
1.Eruptions occur when melt reaches the Earth's surface.
2.Melt occurs when rocks pass their P/T curves, or in plain English, they get hot enough at low enough pressure.
3.Melt rises due to buoyancy and in some cases, squeeze (top pressure for instance)
4.Fault systems facilitate the rise of melt and fault systems have a habit of jiggling about a bit.

Right, now where does this talk of tidal movement and distant seismic activity come in?
1. Are you saying this extra bit of squeeze is what forces melt to the surface or
2. are you saying the tidal motion of the crust translates into heat which generates more melt in the crust or
3. are you saying that these motions cause movement along faults allowing melt to rise along established channels? or
4. something entirely different?

A masquerade? Well, mefinks they're close to or within the fallout zone.

there are been slightly increase in activity on tremor in last hour or so..or i'm wrong?

Just whished I were there to witness the show. :)

@Scarlet Pumpernickel #304: Well spotted - but I just have to laugh at that page. I'll explain it.

The nice colored satellite image on the upper right is the New Zealand volcano Ruapehu. I can't remember which instrument was used to create that image, but it is a genuine image of volcanic ash and you can see how the analysis technique discriminates between the ash and the normal clouds (which are shown in white in the image).

That box you see on the bottom was an instrument built around 1988 to demonstrate that volcanic ash can be distinguished from normal ice and water clouds; in fact the satellite analysis techniques came after the original demonstrations of that instrument. That box only indicates ash/no ash in a certain volume - it is not an imaging instrument.

In 2003 another prototype instrument was built (not in that web page saved from 2001, but perhaps try using google and looking for 'g-bird + volcanic ash'). Anyway, this prototype instrument produced images and could detect volcanic ash as well as sulfur dioxide. It served its purpose to demonstrate that the scientific predictions were reliable and also that the existing technology was sufficient to build such devices. Unfortunately no further work was done; the instrument was never developed for routine operational use. It was interesting that the instrument was developed in Australia - a continent with no currently active volcanoes. If you have access to the right journals you can see a later analysis of a data set from that prototype:

Retrieval of Volcanic Ash Particle Size, Mass and Optical Depth from a Ground-Based Thermal Infrared Camera, J. Volc. and Geothermal Research, published some time in 2009.

There simply is no interest in developing the instrument though. Although a ground-based instrument has its uses, the theoretical predictions indicate that an airborne instrument is the best option and in fact the original papers on the detection technique (using the ancient prototype with no images) detail the technique for the airborne situation.

#249: I think the webcams' Google Earth positions are very close to their Real Earth positions.

@bruce stout just looking if these may be triggers for events or time periods when there is more activity. I guess it would extra force of squeeze and also gravity could pull the magma, it pulls the water doesn't it so shouldn't it do the same to the magma, as it does deform the earth slightly when the moon is on that side of it.

I think Henrik and Anna are spot on with the hot meltwater
thing going on.

It seems to me, therefore, that the essential flaw is that the ICAO contingency plan puts too much emphasis on modelling, and does not insist on confirmation from physical measurement. I have my suspicions that this omission is due to a reluctance to commit member states to additional monitoring costs".

de Haan, if you want to make a case that the grounding of flights over northern Europe was a mistake, that's fine. But the insult you offer here -- the insinuation that the authorities didn't give a shit about anything beyond "monitoring costs" -- is totally inappropriate to an adult discussion of the issue; and in my mind at least, it immediately sinks your credibility. If you really think they had no concern for actual loss of life, and major liability arising from same, then you're just a self-righteous moron who has no respect for other people and nothing worthwhile to say. Get off your damn hobby-horse and quit pretending everyone who disagrees with you is scum.

Slope activity seems to have ceased for now, and our friends are gone. Back to a barren landscape and I fear my personal life will soon be barren as well: my wife and friends can't stand my hours spent staring at this volcano. I guess I should apply for a Geology degree after all I learned through your precious information. Thank for you, folks.

http://news.nationalgeographic.com/news/2002/02/0215_020215_volcanohunt…

Are Volcanic Eruptions Tied to Lunar Cycle?

By the way Next phaseFull MoonWednesday, 28 April 2010 at 12:19 PM for Iceland, will it start up again :P?

In what I hope isn't going to become a habit, I must remind people to keep some level of decorum. Disagreement is fine, just don't use it as an excuse for trash talk.

I like the conjecture but somehow the only analogy I can think of is holding an aerosol can over an open fire and then trying to explain the resulting explosion by pointing at the moon.

It just sounds kind of unnecessary when there are already so many other obvious explanations for an eruption.

Regarding all the lunar/solar cycle discussion - although it is interesting, again, we must be very careful not to confuse correlation with causation. I don't think we have nearly enough data to connect these events directly, and even so, we also don't have an effective mechanism to why they would change activity beyond vague notions of gravitation changes. Not to say that they might not be real, just to take it with a health grain of salt.

lol err.. I hope it is clear that my comment #369 was adressed to Scarlet Pumpernickel #363 and # 367.

@bruce stout that's like watching the sea move and pointing at the moon? :P?

And when standing on the moon and feeling an earthquake (when it has no core it is thought because it has no magnetic field --> so it's earthquakes are tidal?) and pointing at the earth?

Here are at least four different kinds of moonquakes: (1) deep moonquakes about 700 km below the surface, probably caused by tides; (2) vibrations from the impact of meteorites; (3) thermal quakes caused by the expansion of the frigid crust when first illuminated by the morning sun after two weeks of deep-freeze lunar night; and (4) shallow moonquakes only 20 or 30 kilometers below the surface.

The first three were generally mild and harmless. Shallow moonquakes on the other hand were doozies. Between 1972 and 1977, the Apollo seismic network saw twenty-eight of them; a few "registered up to 5.5 on the Richter scale," says Neal. A magnitude 5 quake on Earth is energetic enough to move heavy furniture and crack plaster.

And what about when the sun/moon line up, the Amazon River Flows backwards

http://hubpages.com/hub/The-Tidal-Bore--An-Awesome-Ocean-Phenomenon

#346, Scarlet Pumpernickel,
Where do you get the idea that the Sun is powering the Earth's magnetic field, convection and volcanism from that article? There is not even a mention of the Sun in it or the need for an external source.

It is quite well demonstrated that the Earth does not need external energy to power its magnetic field. The article explains it quite well.

An other observation that demonstrates the insignificance of the Sun in generating our magnetic field is the lack of a strong magnetic field around Venus, which is the same size as Earth but closer to the Sun. If the Sun powers Earth's magnetic field wouldn't Venus' be stronger?

Io's core is heated by tidal heating effects http://adsabs.harvard.edu/abs/1979Natur.279..767Y

Io is in a 2:1 mean-motion orbital resonance with Europa and a 4:1 mean-motion orbital resonance with Ganymede, completing two orbits of Jupiter for every one orbit completed by Europa, and four orbits for every one completed by Ganymede. This resonance helps maintain Io's orbital eccentricity (0.0041), which in turn provides the primary heating source for its geologic activity (see the "Tidal heating" section for a more detailed explanation of the process).[33] Without this forced eccentricity, Io's orbit would circularize through tidal dissipation, leading to a geologically less active world.

@Koen I think you are right about that, the core must be self sustaining, powered by the convention heat which is powered by the radioactive decay.

Venus does not have a global magnetic field are that it spins very slowly (about once every 243 Earth days) and the absence of convection in the liquid core (probably because of the lack of plate tectonics for the past half billion years).

And Mercury causes problems in the model

"Mercury is a bit surprising because it has a weak magnetic field. Mercury is the smallest of the terrestrial planets, so its interior should have cooled off long ago. Also, Mercury spins slowly---once every 58.8 days. Mercury's high density tells us that it has a proportionally large iron-nickel core. Its magnetic field implies that Mercury's interior is probably partially molten. In mid-2007 astronomers announced independent evidence in favor of a molten core for Mercury. Using very careful observations of Mercury's rotation, they found that Mercury's core could not be solid.

Mercury's situation was a major challenge to the magnetic dynamo theory. In true scientific fashion, the theory made a testable prediction: Mercury should have no magnetic field or one even less than Mars' one because its core should be solid. Observation, the final judge of scientific truth, contradicted the prediction. Should we have thrown out the magnetic dynamo theory then? Astronomers were reluctant to totally disregard the theory because of its success in explaining the situation on the other planets and the lack of any other plausible theory.

So most take a more conservative route: either modifying the magnetic dynamo theory or investigating Mercury more closely to find out what is so unusual about its interior to produce a magnetic field despite our expectations. Is their reluctance a violation of the objectivity required in science? Perhaps, but past experience has taught that when confronted with such a contradiction, nature is telling you that you forgot to take something into account or you overlooked a crucial process. Mercury's magnetic field is just one of the puzzles of Mercury the Messenger mission will be exploring when it finally begins orbiting Mercury in March 2011. The careful observations of Mercury's spin may have solved part of the problem (the core is at least partially molten), but how has the core remained molten and convecting (even partially) despite Mercury's small size? "

#375: Post #277 already explains why Io is not comparable to Earth.

The supercomputers are pretty much fantasy machines, since until you can actually predict what each individual cloud is going to do or how many will form, it's pretty useless...

This is a typical denialist talking-point: taking even the smallest uncertainty in a predictive model and using it to "prove" the whole thing is useless. And of course, the denialist offers no better alternative predictive model; he just nitpicks over the work of others to find excuses to ignore all of it.

Here, let me try: "Particle physics can't predict the movement of every cloud in the sky next Tuesday, therefore particle physics is useless. Nyah Nyah." See how easy that is? See how TOTALLY FUCKING BOGUS it is?

An uptrend on a chart can't always be just trended upwards, that mistake was made in the 1970s when they thought one dip suddenly produce an ice age.

The assertion that the scientific community were agreed in predicting an ice age in the '70s is yet another flat-out lie made up by today's AGW denialists, and already discredited by people who were actually conscious in that decade. Fact is, Rubbernickel, the actual scientists were starting to predict warming back then, not cooling. Yeah, there was an article about cooling in Time magazine, but that's not a scientific publication. Neither is that movie that showed Paris covered in ice.

That's why we can't predict volcanoes, we are totally blind.

This statement shows the denialist mindset in a "nut" "shell:" the total, reflexive refusal to even admit the possibility of knowing what the denialist doesn't want us to know. This is a classic case of an idiot thinking that what he himself doesn't understand, can't possibly be understood by anyone else either.

This is a life-and-death issue we're talking about here, and the denialists are going out of their way to trash the scientists who are trying to answer important questions, offering nothing better themselves, and showing an almost depraved indifference toward the welfare of the people actually affected by the issues. The fact that AGW denialists would hijack a thread about volcanoes and air safety, just to keep on bashing the scientific process itself, speaks volumes about their values and their credibility.

According to news there has been small to no ash fall from last 24 hours of the eruption.

The deflation appears to continue as it has over the past days. But also according to news there is more melt water coming from the GÃgjujökull at the moment. There also appears to be some subsiding of the ground there, but I am not sure what the news mean by that.

http://www.mbl.is/mm/frettir/innlent/2010/04/23/ekki_tilkynningar_um_os…

Bruce @ 369/371

Ummm...I think that you might require a sharper [Occam's] razor to give some customers a sufficiently clean shave?

;o)

[/snark] Sorry Erik!

@Raging Bee

(a) Computers don't work in their current models
http://news.bbc.co.uk/2/hi/8462890.stm

(b)1970s cooling blast from the past, notice the same techniques are used, floods, storms, famines. Check out the chart they used, skewed to make it look like falling off a cliff. Now they have just skewed it the other way. http://www.time.com/time/magazine/article/0,9171,944914,00.html

(c)Why is it necessary to call people that question science which is not proven "Denier". That's the same technique that the eugenics movement used. They also had a consensus, it was not questionable, and they had world wide conferences every few years to discuss their knowledge with lots of political figures turning up. The fact that everyone is getting upset about it means it's a religion rather then science, since nobody gets fired up about other scientific areas.

Remember the Son of Darwin had a worldwide consensus in 1932 (Extract of NY Times 1932)

"Major Darwin Predicts Civilization's Doom Unless Century Brings Wide Eugenic Reforms

August 23, 1932, Tuesday

Page 16, 383 words

Eugenic reforms must be adopted within the next hundred years if civilization is to go on, was the message of Major Leonard Darwin, son of Charles Darwin, founder of the modern theory of evolution, read last night at the Third International Congress of Eugenics, which opened yesterday at the American Museum of Natural History."

@ Hasis ha! high-five ... precisely.

#376, 377

Plate tectonics is powered by convection, not the other way around. And if the Sun powers magnetic fields, Venus' rotation would not matter, or would it? Please, get your basics right before posting new theories.

Mercury is the least studied planet in this Solar System (well, since Pluto got demoted, anyway). Whatever the Messenger mission will teach us, I'm pretty sure that it will not teach us that the Sun powers our magnetic field, convection and plate tectonics.

Just a little something from a particularly well known 'religious' group that I thought was interesting:

http://www.geosociety.org/positions/pos10_climate.pdf

The Met. Office predicts easterly surface winds for the next few days. As for the plume, I suspect you'll need to delve into the aeronautical weather forecasts to get an idea of where it'll be going.

#382

(a) You forgot to add "to make seasonal predictions". Short and medium term predictions work pretty well, which were used for the ash predictions. You take the failure of a model for long term predictions to denounce the success of multiple models for short and medium range predictions. They have their short comings and uncertainties, but they are very usable.

@Koen I corrected myself earlier above that the sun doesn't power it.

@Pumpernickel #382: You're conflating long-term predictions with the short-term predictions. Weather modeling for 24 hours is excellent and very good results can be obtained even for the 5-day forecast. None of that has anything to do with the forecasts for months in advance, which no one can reasonably claim to get right. One of the primary models used in predicting the location of the volcanic ash isn't even a weather model, it is a wind forecasting model. The wind model is very good for 24 hour forecasts and even for 3-day forecasts it is remarkably good. people who say the Met Office can't get the volcanic ash prediction right because they can't get climate predictions right have no idea what they're talking about.

Scarlet Pumpernickel has a lot of areas of interest -- climate change, solar spots, computer models, tides, changing magnetic fields and other planets to name but few. Personally I find it tiresome when the discussion goes into these swirls but if others here find it educational/entertaining I'm not complaining.

@Hasis http://www.populartechnology.net/2009/10/peer-reviewed-papers-supportin…

Seems like not all the physicists agreed? http://physicsworld.com/cws/article/news/40916

@Posted by: Andrew | April 22, 2010 3:13 PM

Andrew, you are a pilot, me too.

We are dealing with volcanic emissions risks all over the world with very little incidents.

The same way of operation could have been applied here in Europe but the responsibilities shifted from the operators to the politicians.

Now this has been corrected and we will be flying according to the same parameters as the we fly in any other place of the world.

I have been the air over Europe on Saturday and Sunday with a twin engine aircraft (not a jet). We took out the air filters after each flight and did not find any dust.

There are People really who think the airlines simply take the risk flying through volcanic emissions. Well, they don't and they won't risk anything.
They manage risks and avoid.

This way of flight operation would have been possible on Saturday and Sunday.

I surrender, I don't want to be held responsible for clogging this fantastic blog's [lava] tubes.

Best wishes

@Hasis
http://www.geosociety.org/news/pr/09-60.htm
AGS still looking for hurricanes in the past because none are happening at the moment?

ASC at least has debate science is not dead there
http://pubs.acs.org/cen/letters/87/8730letters.html

Why is it necessary to call people that question science which is not proven "Denier".

Because you act like a dishonest denialist, not like an honest and informed critic. There's a difference. I've heard the same (already discredited) BS from evolution-deniers, Holocaust-deniers, and AGW deniers that I'm now hearing from you. If it quacks like a duck and all that (with apologies to ducks for comparing them to human scum).

That's the same technique that the eugenics movement used.

So now you're comparing today's scientists to EUGENICS? I notice you're not backing that bald assertion with even a specific allegation, let alone a citation.

And why are you dragging Darwin's SON into all this? Are you also a creationist desperately trying to trash Darwin's name any way you can?

AIUI, the Scientific Method is to make up a model (or theory), then test it, test it, test it until it breaks. Then you make an improved model and test it, test it, test it until it breaks. Then you make an improved model and ...

This is really OT, but I have a question about volcanoes. ;-)

re magma chambers and repose times.. how long does it take for a magma chamber to cool off by losing heat to the surrounding rocks? Obviously this a function of the volume and temperature of the magma body, but I guess depth also plays a role as the deeper you get the hotter things are and the lower the temperature differential.

Is it a fair assumption then to state that more evolved magmas are going to develop at deeper levels because at shallower levels the magma chambers will cool below the melting point faster? Or is crystal fractionation actually encouraged at cooler temperatures?
(exposing my ignorance of the chemistry here, but just curious).

@Raging Bee - You need to look at the history of Eugenics, http://en.wikipedia.org/wiki/Eugenics. No I'm not a creationist and I don't believe in Eugenics. A lot of scientists in the early 20th century did though. When science get highly politicized it loses it's credibility. I have my opinions on AGW and you have yours.

Anyway, check out the new volcano footage and lets get off this topic

http://videos.tf1.fr/jt-20h/survol-du-volcan-d-islande-les-images-58244…

Anna@390 --
I find it tiresome, also. Too much to skip over to find some current info.

Andrew, you are a pilot, me too.

Which means you have a vested interest in avoiding any interruption of your work, and trying to deny or disparage any information that interferes with the performance of your job. We understand and respect this interest of yours, but compromising passenger safety is still wrong, as is ignoring some VERY SCARY -- and yes, very RELEVANT -- previous experiences with ash vs. jet engines. Trust me, if there had been no flight restrictions and even 1% of all those affected flights crashed from ash-fouled engines or whatever, that would be worse than 9/11 (that's 11/9 to you Old Europe types), and you would NOT be thanking the ATC authorities for keeping things convenient for you.

Have the Mila cams gone down or are they being blocked outside of Iceland again?

http://www.msnbc.msn.com/id/21134540/vp/36708057#36627492

More flyovers in Iceland

When science get highly politicized it loses it's credibility.

No; when YOU hijack a thread about volcanoes, and use a totally unrelated issue from the past to try and discredit today's science (rather than find real fault with today's scientific work), YOU lose YOUR credibility.

...lets get off this topic...

I'll take that as an admission that you know you've lost the argument. Also, I'll close by pointing out that since you've ruined your own credibility, you have nothing trustworthy to say about ANY topic.

Oh, get a room!

@Dan here also "cannot find server" message.

Thanks Reynir (#386),

I was wondering about this type of weather forecast (aeronautical). Any special links you recommend?

Regarding extra planetary influences on volcanos...

Here is a very rough ad hoc example, which may or may not make sense.

Picture a sheet of glass raised on blocks on two edges. So you start placing weights in the middle. Engineers can use tables to calculate how much weight the glass can take before it breaks, lets say it reads 10kg for the type of glass your using. So you gently place 10kg in the middle, the glass hasn't broken, you can measure all sorts of things tension, compression, polarisation etc as you do it.

You start to add more weight, gently now, it still doesnt break, you can even hear the groans and creaks as you do it. Suddenly someone drops a pencil on 20 meters away and it shatters. No big deal. Try again maybe it was an odd sheet of glass.

You try again and this time it shatters at first attempt. The next you get it up to 15kg, and on and on...different sheet sizes, temperatures etc

It will never shatter at exactly 10kg, you cannot predict when it will shatter only give a probability. That is because the fracture planes are dictated by quantum physics. Perhaps a neutrino coming through anihilated, with neutron absorbtion into a lattice atom, it could be anything. But fundamentally you cannot predict exactly when the glass will shatter.

That doesnt mean you cannot make good estimates, engineers have been doing it very well for 200+ years. Meteorologists also, since that seems a hot topic.

But it does mean you will never get the certainty that so many people want. The universe is simply not like that.

To make it a more relevant argument, now imagine that the glass is instead a huge block of rock, inside a volcano...now is it possible a microscopic influence can cause the huge block to fall? Of course. Predicting excactly when...impossible. Estimating when....maybe. Of course that huge block - might then block a magma channel and bang you have your volcano.

So to the earlier calculations I saw, you would have to use things like Wigner stats and so on. I imagine only a small group worldwide are even comfortable with that. Still there are valid physical arguments for outside influences. Physicists have speculated for years about cosmic ray flux influencing volcanic activity throughout earths history.

Proving it though due to the above reasons has never been done though. It would probably be easier to build a quantum computer first.

In some ways it also applies to the argument - hey we just flew through Europe - no problem. That is like saying I just swam in the ocean so there is no risk from sharks. In fact it is worse, since it is almost asking to prove a negative. Which seems to be what is happening - now we are at the point of - prove it is NOT safe to fly. Prove Santa Claus does NOT exist...

Afterall the theoretical sheet of glass, would still apply to the turbine blades the next time you fly.

Which in my opinion seems a nutty thought process. Anyway hope that adds something to the ongoing debate, even if it is roughly put, hopefully the gist is there.

from CNN

Iceland will close two airports on Friday for the first time, a week after ash from an Icelandic volcano forced the shutdown of airspace over much of Europe and stranded thousands of passengers around the world, the Icelandic aviation authority announced Thursday.

The Keflavik International Airport and ReykjavÃk International Airport will be closed beginning early Friday morning, the aviation authority said, according to a statement on the Keflavik airport's website.

@Raging Bee

"This is a life-and-death issue we're talking about here, and the denialists are going out of their way to trash the scientists who are trying to answer important questions"

Sort of difficult to trash someone who sticks to sound amd verifiable scientific principle and leaves the political agenda to the crooked politicians.

'Notwithstanding the considered opinion of Baillie and Wilson that oaks are âvirtually useless as a temperature proxyâ and âdangerousâ to use in a temperature reconstruction, no fewer than 119 oak chronologies were used in Mann et al 2008.

Among Mannâs oak chronologies were three Baillie chronologies: brit008 â Lockwood; brit042 â Shanes Castle, Northern Ireland; brit044 â Castle Coole, Northern Ireland.'

'Rob Wilson agreed with Baillie on this point, telling the Times that âoaks were virtually useless as a temperature proxyâ'

Yet Mann used them anyway despite the warnings that Oak Death Syndrome and other growth affecting issues would severely taint the data... warnings from the guy that actually collected the data. And, after Mann used them anyway, remained strangely silent about it, despite his previously vociferous stance.

wattsupwiththat.com/2010/04/22/mann-2008-a-victim-of-sudden-oak-death/

Could those of you dedicated to arguing incessantly about climate change and/or attempting to belittle and bad-mouth science please (PLEASE) find a different place to carry-on?

It's boring and most everyone here is for the volcanics.

: P

@ 397 Bruce,
a complex question! The size and depth of the magma body do indeed affect cooling time and rates. A small dike a few meters wide can cool over several thousand years, a km thick sill can take 100s of thousands or more to cool.
The difference in temperature between an intruding magma and the surrounding rock will be greater at shallow depths. This greater undercooling can promote more crystalization along the walls of the magma body. This can work to some degree to fractionate the crystals out of the system, but many will still be in contact with the remaining magma and reacting with it.
The simple model of crystal fractionation involves removing the crystallizing minerals from the magma by floating or sinking. This assumes a nice stable, undisturbed magma body. A bit more complex way is to make enough mineral grains to form a crystal mush and the mechanically squeeze out the remaining magma - filter pressing.
These simple mechanisms of course are just parts of the overall fractionation going on in any magma body. The proportions and rates of each mechanism in any real magma will vary. Then you have to consider mixing, assimilation etc.
Which is why we spend many hours looking at the compositions and crystallization histories of what erupts.

@ Scott #407

I don't think anyone is denying the possibility of cosmic butterflies triggering a volcanic paroxysm, it's just that in the general scheme of things people are trying to come up with workable theories that explain how and why magma ascends or stalls, why it is accompanied with an enormous eq swarm in some cases and just gives us half an hour's warning in other cases etc. Possibly some random neutrino tipped the scales at Eyjafjallajökull that finally led to this eruption but as a causative factor to use in basic models it can't possibly carry much weight (pardon the rather apt metaphor).

FYI, new post for today:

http://scienceblogs.com/eruptions/2010/04/taking_stock_in_the_eyjafjall…

@EKoh cheers! you guys are cool!

Please Do Not Feed the Trolls! They're not going to change your mind or the reality of the natural world and you're not going to change theirs

Now by all means, throw out a speculation and ask why it could or could not be considered. There is no such thing as a stupid question ;) Hey, not all people are experts in the field and genuinely want to know. These people should not be considered trolls.

But if you start out by asserting that your speculation is correct and can only support it by misused scientific terms, a misunderstanding of basic physics and chemistry (on a science blog) and ad hominen attacks and conspiracy theories, well sorry you're not worth the effort needed to respond.

Erik runs a civil and respectful blog and most old timers and newcomers here respect that.

@ 411 EKoh

I have nothing really to add to your comment, except that the variety and magnitude of the basalt columns that are created by that crystalization really leave you in awe of the processes that shaped the landscape:

http://picasaweb.google.com/philipp.salzgeber/Island2009#53565484909153…

This is a view to the east facing Entujökull, a outflow glacier of Myrdalsjökull. To the right you see a cut through a layer of lava consisting of giant basalt columns, for size comparison check the person to the lower left.

and now let's switch to the new blog post.

I just want to say that coming here has been SUCH A RELIEF from the news sites (like the Huffington Post, for instance) where I try to get information. Reading the mindless screaming that goes on constantly is so depressing. It's really encouraging to find people who just want to know what the facts are. (Of course this is a science blog, not a political blog, but then again some people can make anything a screaming match).

Anyway, thanks to everyone who seeks civil discourse. It's our only hope.

Amen to that EKoh.

@renee, You didn't upset me. But I do get annoyed when I see people asking questions about things that are in plain sight. I often do make the same mistake my self, but over time I have learned to take my time to read what is the web page, not just glide over it fast.

I also learned how to use google for my questions, that also helps in learning how to study and to do research on your own.

Please to keep posting here. It was not my plan to make you stop posting here, not at all.

@Raging Bee | April 23, 2010 10:41 AM

If you live your life according to the precautionary principle currently in place in the EU you would not dare to come out of your chair because it is too risky!

We are all sane people and nobody of us is willing to take any risk
with a few hundred passengers and a multi million dollar plane!
NOBODY

But as stated, Flight Ops is capable enough to judge any risk and handle it accordingly, including volcanic ash as it is done all over the world every day.
We don't need no politicians to shut down any airspace!
That's my point.

@Bruce, just to finish off here. If you read through the previous posts you would see the general questions I was answering.
You would also recognise the inherent problems of modeling such systems. Which was the point of my post. Not saying it can't be done, but the limitations should be understood.

new blog people

We are all sane people and nobody of us is willing to take any risk with a few hundred passengers and a multi-million dollar plane! NOBODY

"Nobody" is a sweeping statement, and it's false. Every once in awhile, pilots do indeed take risky decisions and get people killed -- and multi-million-dollar planes destroyed. Just because someone doesn't want to crash, doesn't mean he won't make any mistakes or misjudge any risk. Do you think we only get into bad accidents when we want to? That BA pilot we mentioned earlier didn't want to deal with all four engines failing at once and dropping from 30000 feet to 12000 before restarting; but guess what -- he did anyway.

As for "politicians shutting down your airspace," I thought you'd said earlier that the decision had been made by bureaucrats who couldn't get in touch with their superiors over the weekend. Then again, you also had two different reasons in two different posts for why the restrictions were lifted.

Passerby at 91.... You got that DEAD on.

Maddy at 361. Descending to lower would put you generally into a denser cloud...Lift bubba lift. The 747 was in a plume in the altitude stratum and it was dark outside. He didnt have a clue of what to do about the problem cause he couldnt see it.

He didnt descend to restart the engines, he was falling like a rock with an airplane that had some sort of control to it. Not on the fly by wires folks. You are on an airbus then you likely have minutes to live because when the power goes out, you go out. Then there are the critical phases of flight. If this happened on a descent, or a climb and the air data system quit functioning it would be all over but the shouting.Thats what I am saying, the computers wouldnt be able to work and likely would kill you because they are dumb. You would take over and then be getting the same info that a dumb computer was working with. How about a diving restart if the APU is cooked? Gotta know when to light the motor off but the airspeed system is screwed so its not just the engines and lookit... the bleed air valves were stuck on the 747 too. HMMmmmmmmmmmmmmm..............

Everyone is right though... this is about as dumb as a box of rocks.

RBee... in todays real world and the upgrades in the systems to more and more high tech, that same 747 with all the gizmo's I would say IMO wouldnt have come back. Too many interdependent systems and no way to lock them out so the thing can figure out basic height, Airspeed, engine speeds, EGT, EPR and AOA. I knew a pilot that carried a cross in an MU-2 once. I knew he was an atheist. I asked what THAT was for. He said it was artsy for starts but he knew that if he lost the indicator system (well known for it) that the cross would hang from a screw in the top of the airplane and it would tell him whether he was straight and level or upside down if the cross was on the ceiling. I can tell you that a rosary wouldnt help if an Airbus lost both engines from the causes all seen here. Someone posted that it will take an incident or accident to get their attention...

I fully agree.

After reading through the throng of comments posted here throughout the day, I should leave a couple of notes after a day out on Etna (with a lot of rain and gale-force wind but no new volcanic events at our volcano).

@Raging Bee (raging indeed :-)) - the famous BA flight that ended up in an ash cloud leading to the failure of all four engines one after the other (not all at once for the record) was in 1982 in the middle of the night and the pilot had not even the faintest idea that there was a volcanic eruption somewhere in the area, and no one had informed him. That was not the practice at the time. So certainly he did not, I say NOT decide to fly consciously through a volcanic ash plume. He and his crew did act heroically and brought the plane and everybody on board safely back on Earth, and here's the story in the detail:

en.wikipedia.org/wiki/British_Airways_Flight_9
www.ericmoody.com/

Re: the influence of lunar phases, planetary constellations and solar activity on volcanism and earthquakes.
There may be some minuscule influence of these factors on volcanism and seismicity. If this is so or not, we don't know, and we won't really know for some time I fear. But for someone who tries to understand when, how and where a volcano will erupt, this is not a matter of major importance. We look for the signs a volcano gives before it erupts (there have been plenty prior to Eyjafjallajökull's current eruption, and also Etna has given us some subtle messages in the past 3 weeks, which have put us on some sort of alert). These usually allow us to make statements of the kind "an eruption is likely to occur within the next few days to few weeks" or similar. Now if a lunar phase or heightened solar activity can accelerate the process leading to a volcanic eruption by a couple of minutes, a few hours or even one or two days, it really doesn't change much for us. The eruption will occur anyway. So that's why none of us - after a series of studies launched in the 1950s to 1970s and then essentially abandoned - is wasting much time reflecting about influences coming from space because they do not change the overall way of things. They may change a tiny little bit in the timing, but nothing more. And in the case of an imminent earthquake, where prediction is for the moment virtually impossible, such influences matter little as well, because the only thing we can do to defend ourselves against earthquakes is constructing safe buildings. Whether the moon pulls the earth or not.

Still @Raging Bee, I perfectly understand that you are aware that Eric Moody, pilot of the BA flight in 1982 did not know about the danger from the ash plume. I perfectly understand what you want to say, but I had to make this clear to anybody who might not have understood. The problem in 1982 (and still in 1989 when another 747 had a similar incident at Redoubt in Alaska) was that there was not the knowledge we have today. Today, someone who decides to fly (or order to fly) while there's maybe ash in the air is much less innocent than Eric Moody and the other pilots that ended up in near-tragic incidents in the 1980s.

I think in the end, Ash clouds, AGW anything, UK long weather forceast, the most important thing is science is to take Observations and not rely on computer models. Since if you rely on computer models, you must know every single tiny variable, and we don't know every single little variable. Science gets problems when it thinks everything in nature follows perfect mathematics every time, and it doesn't.

All we need to look is the current temperature and IPCC's forcecast for the future for a great example of modeling and it's pitfalls.

http://paulmacrae.com/links/wp-content/uploads/2009/04/ipcc-vs-real-tem…

I do agree with the previous posters that the decision to fly is all about money in disregard of the risks involved. It was proved to me today after I spoke with Airfrance representatives. I tried to change the date of a Toronto-Budapest flight (via Paris) on 24 of April 2010 for my underaged niece but they refused. We, the family, considered it to be still unsafe for her to travel alone because her final destination is not Paris and the way the airline handled the crisis with people sleeping like cattles on the airports floor for days, doesn't give us peace of mind. I told them that I would like to change the date of her ticket so I can go with her(she's seventeen). They refused, telling me that "the passenger doesn't show to be a minor because she holds an ADULT ticket"- yet they have her DOB on records... this is blindness caused by stupid greed.
It is all about money

@R. de Haan #420: Yes, your 'flight ops' do such a wonderful job that an average of several aircraft per year are scrapped and a few more receive complete engine replacements, for a total of roughly 10 aircraft per year reported to encounter volcanic ash. Did you ever bother to look for facts gathered by people studying the problem? Even using google and 'reporting of volcanic ash encounters' gives you a lot of information. There are no globally accepted procedures; all VAACs issue their warnings but as far as I know no one is required by law to follow the warnings (but if there is an incident, the courts will have absolutely no sympathy for operators who ignore the warnings). Since engine manufacturers would not provide information requested, VAACs will exclude all areas where satellites or pilot reports confirm there is ash or where the satellite information is lacking due to atmospheric conditions, they will rely more on the models. Now that engine manufacturers are beginning to provide information, the conclusion we come to is still that any detectable level of ash is to be avoided (since the figures the manufacturers are providing really are very low). So, flying just because you tell yourself it will be safe is not sensible; neither the engineers nor the scientists agree with you. If you're lucky you will never encounter enough of the material to do substantial damage.

@kruger #424: I know all 4 engines were out; I said you'd better hope for clearer skies at lower altitudes because there's no way you're gaining altitude in that condition - similar reason why an attempt to turn 180 isn't recommended.

@kruger: Here are a few quotes from Marianne Guffanti at an aircraft safety conference a few years ago:

"An important lesson learned by experience is not to try to climb out of an ash cloud because doing so increases engine-operating temperatures and thus can cause more buildup of molten debris on engine parts, resulting in rapid flame out of all engines."

So, climbing out is not recommended even if none of the engines have flamed out.

For the self-proclaimed 'experts' who believe they know it is safe to fly because they didn't crash and couldn't see clogged filters (though I doubt they know what they are looking for):

"... the crew noticed nothing unusual on their instruments or by direct observation. Upon arrival in Sweden, the engines were visually inspected, but no damage was noticed, and the aircraft flew another 68 hours before its return to California. Subsequent borescope analysis indicated clogged turbine blade cooling passages and blade coating erosion; the cost for disassembling and repairing all four engines was US $3.2 million."

In that particular instance it took a long time to convince scientists that the aircraft actually passed through a volcanic plume because none of the usual signs were noted by the pilot.

I'm also confusing the number of reports with the number of encounters; about 5 aircraft per year are damaged by volcanic ash, not 10. This is despite the ongoing efforts to detect the hazards as early as possible.

Oops .. at #361 I got the timelines screwed. Stupid memory, why is it so defective? The original ash imaging was done with the satellite instrument AVHRR (which produced that pretty image of Ruapehu); the non-imaging flying box depicted was built and flown in the early 1990s.

http://dsc.discovery.com/videos/stephen-hawking-aliens/

Back on the topic of orbital movements. It would also be interesting to see if volcanism on earth was greater or less during periods when the earth's orbit around the sun was more circular compared to more elliptical? Maybe this is why venus is quiet at the moment and was more active in the past?

Solar connection related to magnetism is whether solar wind affects the Earth's magnetic field.

One throwaway idea, the reduced magnetic suppression of the nuclear reaction could increase the heat produced by the core causing greater liquidity of the surrounding material. That would make it easier for the core to respond to tidal forces and the greater movement permitted could have tectonic consequences from the changes in the gravity influence of the core?

Maddy at 431. Its night, you cant see and you know the way you came was safe until a few moments before. You dont know if its below you above you, in front of you. The one place you know you werent seeing St. Elmo's was 3 miles back. Not a big decision for me. There simply isnt another one unless you have had an advisory that it was clear below... But, if they got it wrong you are now giving up time for an advisory that could be hours old.

Case in point. Gaua might go. The amount of airspace that isnt covered by the VAAC accurately is incredible. In fact its a guess at best and now we have knuckleheads who want to parse safety.

As for the engines and their erosion? Hey if they are running even in a crappy condition its better than nothing at all. Read that PDF and it describes the whole banana. You do make some very good points though.. 5 a year? Okay, I'll buy that. Anyone want to be on one when the fireball erupts out the tailpiece and takes the aft fan with it? How about a compressor stall? It IS one of my favorites and good for bending blades or shucking them muthers right out the back. But the all time for me is a broken fuel nozzle. Saw one break after an engine overhaul once and the others just kept right on chugging as they tried to get away from it. The fireball out the tail looked like an F4 in a full burner climbout...

Shortly thereafter when the emergency egress and fuel cutoffs were engaged came my favorite word ....POIT !

Stratified ash... You saw it this week with surface to FL 350. You descend and you flame out you arent going to have a chance in hell to restart it. Altitude is time. Even if it were just an altitude stratum that it was in, you were safe a few minutes before maybe... But a 180 is going to carry you out of it on a reciprocal heading in all likelyhood.

http://volcanoes.usgs.gov/ash/trans/aviation_threat.html

Verbatim that was copied to the aircraft operating manual for MD-11, DC-10, B747-200/400... Havent checked the others. Note the 180 turn directly noted by Ms. Guffanti who also used to be

# Exit the ash cloud as quickly as possible (e.g., a 180-degree turn). DO NOT ATTEMPT TO CLIMB OUT OF THE ASH CLOUD.
# Disconnect autothrottle.
# Throttles at minimum, terrain permitting.
# Ignition on.
# Bleed air systems full on (air-conditioning, engine and wing anti-ice, etc.)
# Start auxiliary power unit when clear of ash cloud.
# Monitor engine exhaust gas temperature (if hung start occurs, EGT will increase rapidly).
# Restart engine(s) if required. If an engine fails to start, try again immediately.
# Monitor airspeed and pitch attitude.
# Crew oxygen masks on 100%, if ash enters flight deck.
# Declare an Emergency to ATC, if warranted.
# Transmit Volcanic Activity Report.
# Land at the nearest suitable airport.

I would assume you wouldnt want to descend in one,....common sense.
Disconnect autothrottle-Remember what I said about it cutting the power or surging it right into the sound barrier?
Ignition on-keeps the ignitors clear of ash as the arc will burn it off or electrovibrate it off.
Throttles at minimum..Dont suck as much in. So a quick 180 and exit stage right.
Bleed air systems on. Helps clear the engine, screw the cabin. They can have a headache and sue afterwards.

APU on when clear.. If the engines shut down you have two options. Forced air from the APU to bring the engine up to speed and then hit the fuel again, but you have power for the control surfaces that way too. (Gliding). Or you can force the air into the ducts and help blow it out of there as it hits the compressor section. Mind if this mother is out and it doesnt start then you just about have to have a compressor wash to get a restart. If there was a non volcanic rainshower I would take my chances by running through it. One is dead, then likely number two is suffering at the very least kind of thought. All the while heading for land of course.

Monitor the EGT (exhaust gas temperature). It will go up? Hell yeah it will, the fuel is burning in the tail section of the aircraft. But you get the drift... Dont go into it, get out of it as soon as possible.

This one isnt in there on that ash encounter checklist but it should be...

Dont worry, there is always the bus.

@Scarlet Pumpernickel [433]

...Back on the topic of orbital movements. It would also be interesting to see if volcanism on earth was greater or less during periods when the earth's orbit around the sun was more circular compared to more elliptical? Maybe this is why venus is quiet at the moment and was more active in the past?

With a variation in the eccentricity ranging from about 0.005 (nearly circular) 0.058, and a variation stretching over about 413,000 years... it's gonna be a bit hard to come up with anything half arsed plausible with only about 37 years of decent quake data. In other words, only about 0.009% of the data can be compared.

However, there are peaks that also show up in the Sun's position on the ecliptic, correlating with the seasons of the year. The problem is, how much of this is related to the huge number of aftershocks that occur during significant events, such as the Bandar Ace quake or the Mexico 7.2, or the Chilean or Haiti quakes. These events tend to load the year at those points and until I can get off my arse and pipe this stuff into a database server... I only have 5 years to go off of. Meanwhile, it's just a pet project sitting on the back burner.

If you want to see a really interesting plot, grab all the data for the Pacific plate / North American plate boundary from the Mendocino Triple junction down to the Rivera, getting all quakes within 100 miles at 100 mile intervals, weeding out the duplicates.

Then, take that set and plot it verses time (x - axis) and Latitude.

You get the weirdest idea that you are watching stress waves running up and down the boundary. A lot of them seem to track as clusters of activity.

Logically, I can see it since it is essentially two blocks grinding against each other. It's mostly chaotic, but there stuff in there that makes you go "hmmm..."

We also could be heading into a Dalton Minimum, Last year we had some very low sunspot counts, and this year the same thing appears to be happening again. Maybe the pressure of less wind on the earth could be having some effect, it is hard to measure though...

http://www.landscheidt.info/?q=node/50

The previous Dalton Minimum had a lot of volcanic activity, which reinforced the sun's activity and plunged us into the little ice age. It obviously wasn't a reduction in CO2 at the time...

http://www.volcano.si.edu/world/largeeruptions.cfm

Here is a list of eruptions in the last 10,000 years...

http://www.utdallas.edu/physics/pdf/Tin_rev.pdf

And an interesting article on how solar wind effect the global electrical system, this would not stop in the cloud layer, it would also be effecting the internal part of the earth as well...

Still trying to flog the same dead horse you said you wanted to get away from, Rubbernickel?

I think in the end, Ash clouds, AGW anything, UK long weather forceast, the most important thing is science is to take Observations and not rely on computer models.

What about computer models that are based on observations? Your false dichotomy is typical of creationists and other science-denialists. So is your insistence that "Observations" (note the capital "O") are somehow Sacred and Not To Be Interpreted.

Since if you rely on computer models, you must know every single tiny variable, and we don't know every single little variable.

Wrong again. As long as you're aware of the limits of a computer model, and update your model as new information comes to light, you're not likely to go too far wrong. (And yes, most reputable scientists routinely do both.) More to the point, a decent computer model will at least give us a general picture -- especially when there's no alternative means of making the predictions we need to make in the time we have to decide. (Remind us again what your alternative to computer modeling is, Rubbernickel? Oh that's right, you don't have one, because you don't really care enough to think that deeply about the problem.)

Science gets problems when it thinks everything in nature follows perfect mathematics every time, and it doesn't.

And how many established scientists actually make this mistake? Oh, and since when was "science" a monolithic "it?"

All in all, given the "Observations" of what happens when planes fly through volcanic ash-clouds, I'd say the risks of relying on computer models are more acceptable than those of ignoring them. ("Observations" are Sacrosanct, remember?)

Can someone go up to Porolfsfelli and turn on the lights? :)

I think we're going to see the collapse of the top of the meltwater tunnel soon. Bits are crumbling away and there are two huge cracks above the roof of the tunnel.

There has also been a small landslide from the slope to the righthand side of the meltwater pool.

Assuming the airlines actually did lose 1.7 billion dollars, that gets me to wondering about what sort of cost calculus they might apply -- as well as what calculus should be applied. It is unlikely that we would want to do away with cars altogether absent the guarantee that by driving them no one will ever get injured or killed in an automobile accident after all.

But the price of a single 747 is in the neighborhood of $(USD) 200,000,000. Assuming a payout of $1,000,000 per passenger and and 400 passengers the airline industry could afford to lose two 747s -- and it would still be cheaper than the 1.7 billion they lost. However, if one assumes a payout of $10,000 to the immediate family (which seems more realistic) they could stand to have lost 8 fully loaded 747s. Then again, if they had lost a single 747 perhaps they could have sued the EU for allowing flights when the EU officials knew that conditions weren't entirely safe.

As I have indicated, I wouldn't argue that the only actions that should ever be taken are those that do not involve any risk. But I don't think that, given the likely incentives the cost calculus that airlines would apply would be entirely optimal, either. Yet it wouldn't seem entirely unreasonable to think that it is this sort of calculus which motivates the voices we are hearing from their industry.

What factors are they including in their calculations of the losses that they would deem acceptable? And how reasonable are their calculations involving the risks that would have been involved?

Footnote http://i45.tinypic.com/smzlzs.jpg

I came to this blog on a humid Autumn afternoon when I had sod all to do. What a fascinating set of arguments it contains.
What nobody has said, however, was how blissfully quiet it was with no planes flying. How no vapour tails spoiled the sky. Hoe much CO2 pollution was avoided. All of which support the "keep the planes out of the sky when there is a volcanic ask plume around" arguments.
Oh for that silence when I could hear birds cheeping (or was that birds coughing due to volcanic ash!!