Eyjafjallajökull chugs along as Europe begins to recover

Over the past few hours there have been more steam and ash coming from Eyjafjallajökull then yesterday, and early morning today. There is a chance that new craters have been opening up. We did see that happen in Fimmvörðuháls eruption. But that needs to be confirmed, currently it has not been done.

OT sort of-Erik in running through some of the links yesterday I picked up a page from USGS that was showing quakes under Katla.

http://earthquake.usgs.gov/earthquakes/world/iceland/seismicity.php

If I go to the USGS main page for worldwide quakes I get zip. De nada, nothing showing and not even a list.

Are there quakes happening at Katla or not, or is this old stuff? I pulled the IMet page and they showed nothing but as you can see someone is registering quakes there.

@ r.kruger the map shows seismic activity from 1990-2006.

@M. Randolph Kruger, There is not anything happening under Katla at the moment. It is quiet. However I must point out that normally we do get earthquakes in Katla on regular basis. This happens all the time and has been doing it for many years now.

The earthquake sequence that is going to happen before an eruption is going to be a lot bigger then normal earthquake level in Katla, it is going to stand out.

Currently there nothing happening. I expect that to be like that for some time to come at this moment.

@ M.Randolph Kruger, here's an excellent place for information
http://hraun.vedur.is/ja/index.html although i'd advise using google chrome which translates the webpages automatically.

Jón (#1)

The 920 AD Eyjafjallajökull eruption was in Skerin. The magma (?) that came up then is identical to the magma in the present crater.

You can see Skerin ("The skerries") on the road atlas map I linked to earlier:

http://www.icelandroadatlas.com/index.php5?cmsszp=icelandroadatlas&cmss…

Kind of semi-circular (crater rim?) the Skerries are in the NW part of the glacier, jutting up through the ice.

Well, with air travel resuming, I thought this would be an interesting note to add to your udpates Erik. A Thomas Cook 757 out of Manchester had to turn back to the airport yesterday after a heavy smell of ash in the cockpit/cabin and subsequent failure of one of the engines bleed air valves. The pilot immediately turned back and was able to land safely with both engines functional; however, it shows the danger still present in the skies. They encountered the smell around 16000 and up to 30000. The plugging of the valve showed there was enough contamination to begin affecting the airplanes engines. Thankfully the pilot decided to begin his return back to Manchester immediately. I haven't seen a single mention on the news yet, but you can see more details and the ATC audio at (you have to be registered on the forum to actually listen to the audio): http://www.liveatc.net/forums/atcaviation-audio-clips/tcx952p-turns-bac…

Is it my imagination or is the plume looking more vigorous than yesterday? It also seems to be rising higher into the sky and Jon's recorder seems to show more activity.

Wahoo! Sky News put my photo on their website.

http://yourphotos.sky.com/

Its picture 39 out of 57 on the Volcanic Ash photos. Have a look!

:)

Just a short summary of (maybe stupid???) speculations about our Iceland-Volcano, which I have read in several "serious" german newspapers:

1.) "The tremors of Katla could be overheard by the tremors of Eyjafjallajökull???"

I don´t think this is possible and it was not discussed so far by the experts here!

2.) "The volcano "shrinks" according to the GPS datas, that means the eruption would end soon, because the magma chamber is going to be empty soon???"

I don´t think, that this is a clear proof of what will happen next. We had this down movement during the first eruption too and we all saw of what happened.

3.) "There will be soon lava flowing down the mountain."

Then a huge amount of magma has to come to the surface to fill the old crater which is unlikely. But there is still a lot of ice, so we would have massive explosions again and floods....

@Anna, the type of magma in a eruption only tells half the story. It is not clearly known what type the eruption in 920 and 550 was. But Eyjafjallajökull appears to start with a fissure eruption in many cases. This appears to have happened at least in 1821-1823 and now in 2010.

This fact and other warrant a bigger and better study on Eyjafjallajökull and other Icelandic volcanoes.

My sensor is just going oddly high, it does not appear to be related to wind (5.4m/s currently). Something is going on it seems.

@ Jón 4:

Really? I'm sure I saw a post by someone in the last few days which suggested Katla had the potential for aseismic eruption, like Hekla?

Yup, tremor activity increasing again.
http://hraun.vedur.is/ja/Katla2009/gosplott.html

Maybe more meltwater release.

Gorgeous view on the Valahnúk right now, with the sun at that angle. Other than EJ looking like a radiator that's overheated, of course :)

Good morning.

Gosh, I'm sorry I went to bed just as a juicy discussion started about science, communication, misunderstanding;-( (previous thread starting at 273 (kicked off by George, then discussed with Henrick, Holger, Boris, Frito Lay, Scott, John,Bruce, et al)

Re paradigm shifts: Einstein said something to the effect that you can't solve a theory with the same thinking you used to create it. That is, we need a paradigm shift to test the the next great problem of science.

My hobby horse: My opinion is that the general lay public (including the media and politicians) thinks that "theory" equals "opinion". Perhaps general understanding could be advanced if every scientist opened their public discourse (when in the lay environment) with a description of the scientific method: theory, test, observe, conclusions (both positive and negative), replicaition, re-theorize. I think both Boris and Jon are involved in this process in it's purest sense: What are the data?

Re sloppy science: As a lowly lab tech, I remember listening to some post-docs discuss how they fudge the data. (Not to mention stories of fisticuffs at conventions between scientists with rival theories) Even scientists have to be right in their theory! Which makes it opinion, not science. I now look for replicated experiments before I trust my science information. And, at least in the US, scientists are under great pressure to have a 'correct theory'. The funding agencies don't seem to realize a negative finding is important to advance knowledge.

Finally, George calls scientists prima donnas. Clearly, he's not had to work with engineers lol ;-D

Sorry to be off-topic, but this is a favorite discussion of mine.

Thanks to everyone who stayed focussed on the volcano and pointed out the Vodaphone picasa as showing the new river bed. Great views today!

Thank you everyone for being so civil. It's such a joy!

Clear sky and low or no wind around the volcano. An occasional explosive event. My best wild-ass guess is that there is only one active crater.

Is that a lava flow to the left on the Hvolsvelli cam?

http://hraun.vedur.is/ja/Katla2009/Myrdalsjokull.jpg

On the above map can anyone tell me where the hau tremor sensor is located.
http://hraun.vedur.is/ja/Katla2009/gosplott.html

I believe black traingles or tremor sensors?? Are these correct assumptions?
god is godabunga
mid is midmork
esk is Eystri-Skogar
hvo is Lagu-Hvolar

When people say nothing is happening at Katla - aren't these sensors connected more to Katla distance wise??

Mmm... Nahh... I think it's a shadow cast by the column.

@17 ... I think it's just shadows giving the illusion of steam ... sorry.

@Fireman, Katla is still quiet.

@JB, Sensor named hau is in Haukadalur, close to Hekla. In fact it is just ~3.6km away from my sensor that is ~15 km away from Hekla. I haven't had many earthquake to figure out the distance yet.

The wind appears to be increasing according to wind measurements in the area.

parclair,

I work with engineers every day and yeah, same goes there as well, particularly with those who are in more of a design role vs. those in a sustaining role.

But I have never seen it in engineering to the level I have seen it in academic labs. It can be quite funny, actually. I recall hearing of one lab (Berkeley Livermore) where a particular scientists insisted that people address him as "Doctor", even people who had never met him before and weren't aware of his title. So a certain maintenance director insisted that his people address EVERYONE in the lab as "Doctor". So from that point on, everyone those technicians talked to was "Doctor".

It can get quite comical.

Since it is not snowing anywhere, you can see all the ash being blown around on this cam. It looks like a blizzard.
http://www.ruv.is/katla

Eh.. Dan snow is white ash is grey/black therefore as the ground is turning white i would say its snow... snow doubt.

@18 JB: I just made a more accurate and clear location map for those seismic stations:

http://img402.imageshack.us/img402/588/icel.jpg

Is it just me, or did the amount of steam on Valahnúk just ramp up big time?

#Jón (11)

Someone did a lot of research on the 920 eruption for his MSc dissertation (2009) so they must know a thing or two!

I mentioned Skerin in my post because someone (Passerby?) was wondering if a new crater was opening up in GÃgjökull at this very moment. You yourself are talking about the possibility of new craters opening up.

All this is pure speculation of course. But everyone here enjoys speculating and idly wondering what happens next.

Question is: If (a big if) a new crater or fissure opens up where exactly would that take place? Presumably there have been eruptions at the summit (or Goðasteinn) before. The 920 eruption was in Skerin. I think the second phase of the 1821 eruption took place in the south facing flanks of the volcano.

Could a new crater/fissure open up just anywhere in Eyjafjallajökull?

On this blog you can find an interesting geological map of Eyjafjallajökull and environs, and the dissertation I mentioned (pdf):

http://vulkan.blog.is/blog/vulkan/entry/1044277/

Looks to me there's a cloud bank sneaking in from the south.

@Kaboom: *groan* You're waffle!

All the news is talking of Katla's history and its potential.

What are the first signs that the scientist will look for to Katla re-awakening? The only thing that I've read is the the tremors should be more significant than the current tremors.

I lived in Oregon USA during Mt. St. Helens eruption - the daily life with ash fall I understand very well.

http://www.fs.fed.us/gpnf/mshnvm/ coming up to 30 years ago.

@ Reynir Heiðberg Stefánsson what an intellegent comment thanks. Oh look at the http://www.ruv.is/katla cam the white ash has magicaly vanished, maybe it was snow after all.

I wish that cloud on the Hvolsvelli cam would make like a bee and buzz off ! Anyway could someone please explain to me the difference between low and high frequency tremor in terms of what they indicate, thx.

Most likely. As far as I know, the ash fall is nowhere close to Mt. Háfell where the Katla-cam is.

@Austin, Your right, the plume has not risen that high in a couple of days...

@ Kaboom Shows what I know, but what do you expect, I'm from Florida. Ask me about hurricanes though... :) (actually when I first said that, it looked grey to me and I didn't see any snow in the area on weather sites) mea culpa

@30 JB, the CVO (Cascades Volcano Observatory) has a wondeful online presentation on MSH 30th Anniversary:
http://vulcan.wr.usgs.gov/Volcanoes/MSH/30Years/framework.html

@Dan: You just learned exactly why you have to overexpose by a stop or two in snow. If you don't, you get a grey mess.

@Dan i was just trying to point out that it was snow, i'm naturally sarcastic so sorry if i was a bit abrupt. Huge jumps in tremors at the moment i don't know what that means all i know is that snow is white.. :)

@Anna, One study is good. But more is better. But there is no surprise in the fact that the volcano is making more of the same volcano material as before.

As for where the snow came from, I rather suspect that sneaky-looking cloud bank on the MÃla cams.

For those of you looking for a more light-hearted report on the eruption, this is great (especially the last minute or so):

http://www.thedailyshow.com/watch/mon-april-19-2010/volcanolypse-2010

@Reynir Now that I can understand from taking pictures from our beaches, which are extremely white. http://piercam.net/
@Kabloom I actually took it as sarcastic humor, which does not always come across in type, and thought it was rather funny. Snow what I mean?

Jon some pretty sizeable activity on your helis the past 4hours, is it all down to that slight wind increase you mentioned?
It looks like the seismos are heading for three day highs apart from esk and hvo btw.

Erik I posted this in the last thread but it looks like you guys have moved on so I am posting it here for Erik or Boris;)

25 Boris speaking of Gaua....Do you really think it could end in a possible Krakatau type event?

"But this time, it looks like the situation at Gaua is getting more serious. If not a cataclysmic (like, Krakatau-type) event"

Are we talking about a possibility of the whole caldera erupting or just Mt Garet? If we are talking about a 6 x 9 km caldera eruption then I am going to change the channel from EJ to Gaua. Please correct me if I am wrong but....the eruption of a 6 x 9 km caldera would be roughly the equivalent of any Katla eruption?

Posted by: Randall Nix | April 21, 2010 11:26 AM

Bless the BBC for balanced reporting that avoids shrill sensationalism and strident alarmism.

If I read the article correctly, and with respects to those impacted more directly, this eruption is primarily a show for the likes of us here at Eruptions.

I'm grateful for all the webcams, photos and insightful commentary.

BWAHAHAHA! That was deliciously nutty!

@27: nope, not me. Did not speculate on any new crater opening up on GÃgjökull. Geologists specializing in study of Eyjaf have suggested that a southern flank failure could occur above an active hydrothermal field, an area that has been associated with previous seismic swarms in the recent past.

IR imaging by the Institute focused on the crater. It is not the only major heat source. I'm interested in the geometry of the Fimm fissures because the NASA EO heat detection satellite images linked here yesterday show what looks to be a near circular thermal footprint.

It's rather large feature. And we've had recent seismic activity reported near that location.

For the last three or four hours, the eruption plume has been a pristine white, whiter than the regular cloud drifting in and out of view. To me, this is as beautiful as anything produced by the first, Fimvörduhals episode. She really is a delicate, dainty Lady, most pleasant to the eye!

Quare: Is it possible that the surface in one crater has solidified to the point where melting water is instantly turned to steam without shattering said surface?

@41 LOL. My understanding is that the volcano has no name. It's the volcano UNDER Eyjafjallajokull. Kevan it is.

There is now a news about the sudden increase on the plume on mbl.is. They are not sure what is going on at the moment.

@ Passerby - That large near circular thermal footprint in Fimmvorduhals is likely cooling lava from the two fissures there.

Did anyone else notice the meltwater release between 12:10 and 12:20 photos on Vodaphone picasa?

Looking at the most recent vodafone pics (70-86), it really looks like some large cracks are forming. It looks like a large piece is ready to fall off? Am I mistaken?

@ Jón - yes, Katla is quiet, quiet as a mouse. But then so is Hekla (typically) until 90 minutes before eruption. Or so I've read. Could Katla be the same? That was my question...

@53 The area is a definite watch. Fimmvorduhalsi is the most interesting view today.

New crack (or run-off channel?) in the glacier throat (Pforosfelli view), just to the right of the centre dark channel. It wasn't there at 12:30 pm EST, but is there now.

@18 JB: I just made a more accurate and clear location map for those seismic stations:
http://img402.imageshack.us/img402/588/icel.jpg

@25 Mr. Moho Thank You I appreciate this. During the Mt. St. Helens WA USA eruption 30 years ago, the US lost several scientist. You are all in our thoughts.

@Fireman, It is hard to know. Because we never had a full scale eruption since recording started on earthquakes.

SAMOA ISLANDS REGION just had a Magnitude 6.2 earthquake according to the USGS

@ beedragon (65): I think it's a run-off channel, not a crack. See here:
http://extras.vodafone.is/trailers/fimmvorduhals/mx10-4-235-80/2010/04/…

Here's something for your amusement - Iceland or Mordor?

buzzfeed.com/mathieus/iceland-or-mordor-8q4/

Enjoy!

@Pika (60) I think you're right. Thanks for the vodafone link.

#56: I think it's a mud flow. It appeared after ca. 16:20, the last snap I have from the Vodafone cams on Ãórólfsfell.

@JB 57: Great map! Thanks. It would be nice if you could label Katla on the map.

Yes...the new pics just posted and it does look like a mud flow. Big one too. Thanks

@beedraagon, you've got good eyes.;-) Now, has the glacier slid down to the left of where the voldaphone 840 crack appeared?

Now, turning our attention to valahnjuk, is there a non-volcanic fissure in the glacier developing horizontally, dead center? Or, is it just the contour of the landscape highlighted by the snow?

Did anybody notice who one of the supervisors was on that 2009 master's thesis mentioned above?

Magnús Tumi Guðmundsson.....

@Randall (#44), I don't think a Krakatau-like event is likely at Gaua. Like all worst-case scenarios (remember Yellowstone, you do? :-)) it's possible but chances are extremely remote. I did refer to "Krakatau-like" after seeing the video that one post referred to, where there was a lot of talk about tsunamis and the risk of Australia being impacted by tsunami generated at Gaua. Now, to have such an effect you'd need a Krakatau-like eruption, with tens of cubic kilometers of pyroclastic flows plunging into the ocean. Gaua's morphology does not look like it's prone to sector collapse (like Mount St. Helens), which means huge landsliding due to the failure of one of its flanks. A sector collapse would be a good reason for a tsunami, but there I think the risk is low.

I'd rather imagine an explosive eruption generating a lot of ash and lapilli (tephra, is what it's called in our technical language, a term introduced by the grand Icelandic volcanologist Sigurður Ãórarinsson in the 1940s), enough to be a hazard for villages on the volcano's flanks. Maybe pyroclastic flows. Difficult to say - that volcano is even less known than Eyjafjallajökull and much less intensely monitored. So here we are deeply within the realm of speculation ...

@64: there you go:

http://img717.imageshack.us/img717/347/icelw.jpg

@70 Thank you for that. I now have a much better idea of where everything is located.

Yahoo news has a link to 740 photos taken of the eruption and its impacts. The captions are minimal in the extreme, but the photos render very quickly.

http://news.yahoo.com/nphotos/Iceland-volcano-erupts/ss/events/sc/04151…

very interesting discussions here. and thanks for that.

but in order to get some sense of the what the real issue is in the dialog, is a classical one: to distinguish between signal and noise.

here on the western flank of reykjavÃk city (130 km westward from Eyjafjallajökull) there is neither signal nor noise.

einar

strong increase in tremor, increase in water discharge and very high clouds on the hekla cam in the far distance.... another eruption highlight.

@Hanns: remember that there is a 9m/s wind also which creates alot of noice. Have been quite windy all day.

However the plume itself seems to be most steam or something similar. The colour is quite light..

But I cant avoid wondering if the cloud rolling in on katla webcam (which is directed towards eyaf) is a normal cloud or an ash cloud?

The base of the cloud seems to have its origin ontop of Eyaf..

Can someone explain why, in the Picasa album, there is more runoff in slides 84-90? Thanks.Picasa

@ emmie i'm no geologist or volcanologist but i'd say its because more water is melting than in slides 1-84.

"Strombolian" explosions? The thing is spewing pasta over Europe? Does this mean the FSM is angry at someone?

Oh well, if you don't like airline food, you can just stick your head out the window and catch bits of stroboli on your tongue as the plane flies through them (hopefully without getting its engines fouled)...

#76: Despite the titling, the Katla cam is back to watching Katla and thus looking roughly NNW towards Mýrdalsjökull. I'd say it's a normal cloud. The play between shadows and highlights in the ground looks right interesting, though.

A Pinatubo sized event is not involved in long term climate change. It's influence is transient and rapid. Yet Mike Burton of INVS made mention of it in the context of 'climate change' science.

"That's a lot in five days; but Pinatubo ejected 10 cubic kilometres - that's 100 times as much.

"So this is not the big climate changing eruption that some people seem to think it is."

http://news.bbc.co.uk/2/hi/science/nature/8631396.stm

There must be a great temptation to cast grant applications so as to gain successful funding. The eagerness can taint the objectivity of the reported result.

I admire the restraint of the INVS by NOT rising to the bait in a blatantly opportunistic manner and preferring instead to assert strong objective neutrality.

@Raving ... it's INGV not INVS (that's Istituto Nazionale di Geofisica e Vulcanologia, or National Institute of Geophysics and Volcanology) :-)
And I can tell you that our institute (that is, the INGV) is in dire need of funding, like most scientific institutions worldwide in this moment.

#79: You could try, Bee, but likely you would wind up with a lava bomb sitting proudly like a centurion's helmet on your head.

Re: 67 parclair

Indeed the question is, Why is there no snow? Has it been swept away by the wind or is there an unseen heat source that has recently made its presence known. Stay tuned we will find out eventually.

As a British citizen living in western Canada, I just want to say thank you so much for this website!

Since Eyjafjallajökull erupted, I've found it increasingly hard to know what to believe about the eruption, given the wildly conflicting stories reported in the Media.

Yesterday I happened upon this site, and am amazed at the depth of the information about the eruption, and also about other Volcanoes. While I admit that many of the scientific terms go right over my head, I've spent a good couple of hours reading through some of the past postings made, and found it just fascinating!

Thank you for providing so much information! I am one new reader that will definitely be returning!

Boris, just like KVERT, I think all the geological/
volcanological institutions need funding. It seems everything of real importance doesn't get the funding that is needed. It is like an intersection that has stop signs, but really need signal lights. The county involved doesn't do anything about it until several people get killed. THEN maybe they will put up the lights. It seems that no amount of warning gets anything done until something happens. Then, as you have said before, the people get mad at the autorities because no warning was given! Fiddle sticks! We just have to do the best we can to get the message out, which I think you do very well, adn hop for the best. Then, keep studying the volcanoes and learning more about them.

#67, 84: The dark bit in the centre is a sheer cliff above a ravine, the kind where it takes at least an hour and a lot of huffing and puffing to get you out and on to the ICU were you to fall over the edge.

@Dawn #85, welcome aboard! This is one of the best sites I have found to learn about volcanoes. There are some very knowledgable people who post here and it takes me about two to three hours every morning to catch up with what has happened while I get some sleep. LOL Anyway, it is a good place to learn so keep coming and I can tell you, you will probably get addicted. ;-D

#87 LOL ... thank you Reynir. I am familiar with that type of terrain here in western Canada. I appreciate your knowledge of the area and sense of humor. Thanks for clearing that up.

I know little of that particular area but for what I've seen on maps and pictures, but I have been to very similar places.

@Diane #88. Thank you for the welcome. No need to tell me I'll probably get addicted. I think it already happened lol.

Hans and Reynir, I can relate. We have a road that goes on the edge of a canyon and it is curvey! I wouldn't want to drive it at night!

Boris thanks for clearing that up for me. I have been busy the last few days recovering and searching through 47,000+ deleted emails trying to catch a thief. I've only been able to quickly scan the last two days posts.....I always make sure to read yours and Erik's.....that one set off my disaster radar;) Now I can relax and go back to the emails.

@Diane: There are several places here in Iceland with that kind of road. For some, it's even a daily commute.

Y'know, guys... I think there's been a slight increase in water runoff from GÃgjökull in the last hour.

Harmonic tremors continue to do there strange thing, increasing while the eruption appears to be quite low at the same time.

@Reynir, there are cars in the area that say: "Pray for me. I drive Hwy 49!" That is not the road I was speaking about, but it is a very curvey road that trucks don't take it because some of the curves are so sharp and the road is so narrow. Where I live, the fire escape routes are rough, dirt roads (except for one and that one is very narrow) and I have seen some drive down them in Corvettes. Not the best place for them I must say.

I laugh sometimes when I see a road sign on a paved road warning of a rough area and it is just a tiny bump in the road that I hardly feel. LOL Just recently, they have "fixed" a part of the main road and made the curve less of a probblem. This is the second time they have worked on that curve and it is much better. Before there was any work on it, a number of logging trucks would flip over on that curve. I think it will be even better now that they have taken more of the curve out.

I don't envy anyone who has to drive a less than ideal road. :-{}

Tremors are at the third highest level since the eruption began. Any ideas what is causing this. Is it a bad sign.

Aye, and here's the rub: Are they caused by expansion, contraction, dwarf miners or a hard rock garage band?

The NASA Earth Observatory has kindly placed the 13 images that they have published thus far regarding this eruption, in one collection.

http://earthobservatory.nasa.gov/NaturalHazards/event.php?id=43253

The NASA Earth Observatory is a wonderful place to visit.

http://earthobservatory.nasa.gov/

Its Tommy Knockers.

Does anyone see what I see on the Gigjokull? I am seeing a dark spot that wasn't there about an hour ago on an icy ledge.

I coach a football team of dwarf miners so i know they don't produce harmonics like that. Could it be a yeti with Diahorrea??

@Diane, can you be more specific, there are alot of icy ledges out there.. lol

None too sure, Diane, but I think the tongue is flushing more water than it was twenty minutes ago.

@87 LOL! I've had to make the climb around cliffs like that because i'm very clumsy!;-)

Diane-- there are parts of Hwy 50 that scare me-- steep drops with everyone driving at 80-90 mph on wet or ice!

Dawn--welcome from fellow addicts.

@Me 100: NEO has 14 images there now. They are adding them as we speak.

OT @Parclair @Diane: E.D. County?

Parclair, I know all about HWY 50! My folks used to drive that when they went to Tahoe before they put in the new route. When the snow gets really bad, they will open the old grade because it is easier to keep the snow off. Go figure.

Ok, Shelly. I was looking at the Poro cam (not Vodafone) and it is near the middle of the ravine where the water is coming down. It looks like the ice is about to slide off the ledge, but I am sure it isn't. There is a black area on the right side of it. It wasn't there before.

Diane, cams focussed on the lip of the glacier have been the most interesting all day. It certainly looks to me like the dark spot dead center of the mila cam has expanded in the last couple of hours

I think it's Loki yanking his gut chains;-)

Refer to this image:

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

There is now water rushing down the surface of the glacier and forming a waterfall just to the right of the outlet hole from the previous outbursts. It has been growing quite a bit in the last few hours.

Parclair, could it be a big Yeti cowpie? LOL

Yeah, it has been growing, I think. It also seems something else came down that was on the right of the ravine above that shelf. Not sure on that, though.

Last few snaps on Picassa certainly show an increase in meltwater!

I find Jing to be useful for annotating screen shots. Here's an example from the Ãórólfsfelli cam: twitpic.com/1hcxq1

Carla, I used to live in Sacratomato. Now I am in the foothills of the Sierras, but not El Dorado Co. Placer.

@107 No, not El Dorado. I'm in the great central flat of North CA

#113: Looked more like a steinbock to me.

Parclair, Diane... ah, just curious. Got most of the family down there. I'm in the PNW.

@Carla, Very useful reference, lol.

@Diane 114: Hey, I'm in Placer county too! (Rocklin)

If you're close by, you might be interested in my weather website with data from my back yard sensors:

http://www.ipconsulting.org/weather/Current_Vantage_Pro_Plus.htm

Vertical tremor station activity continues to rise smartly. Presumably meltwater movement and glacier stress-related, over the outlet path.

Outlet glacier weakening maybe accompanied by a sudden burst of local EQ activity (icequakes).

Glad we have good viewing conditions today to assess plume activity and runoff rate changes.

I was just looking at the tremor readings and noticed that they are on the rise again, I was wondering why this was as the wind is dropping,, seems you answered my question Passerby without me asking it.. lol

From Jón's helicorder page it appears that wind has slowly decreased to average values (about 5 m/s), but tremors have not varied much, they're pretty much as strong as they were several hours ago. Seismic activity recorded by Vedur.is at GOD station instead, is slowly trending up. It's true, though, that from webcams the weather appears to be very cloudy, probably it's snowing in many places. Bad weather increases seismic noise.

Also, the THEY-REYK gps ground deformation chart has been updated with a recent data point. There's a hole in the data from the past days. Even so, by mentally interpolating the missing values, we can definitely see that there has been marked ground deflation, as reported by GOLA station.

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

However, the strong tremors still remain unexplained.

I'm reading Boris' recommendation about the "tale of two volcanos". i recommend it to all -

http://books.google.it/books?id=2j4rAAAAYAAJ&pg=PA170&lpg=PA170&dq=expl…

Boris, thank you for the timely article.

http://www.telegraph.co.uk/travel/travelnews/7607481/Iceland-volcano-Br…

BA not happy about flight now

http://www.guardian.co.uk/technology/2008/jun/05/greentech.transport

We need to build more of these, for when Iceland is active. They use less energy and are more graceful anyway, whats the rush when travelling, the view from these would be amazing!

Better then a cruise ship.

Agree with parclair there, Thanks a mil Boris, I read the two volcanoes chapter, and its great. I'm finding myself skipping to other chapters now, just reading the Yellowstone one.

Good stuff!

#116 Reynir, that's a much better match, heh.

Tremor is "ringing" again. This beast is full of surprises.

http://www.npr.org/templates/story/story.php?storyId=126172227

Nice pics of the top of the volcano

Now that we have had a fantastic information gather around this volcano, what lessons or information would be useful regarding glacier clad volcano's in more populated areas such as mount ranier in usa?

I choose ranier as an example due to its possibly weakened structure.

Just a thought, although I think a valid one.

Erik, I think you should thank Eyaf' with a raised glass for making your blog ever more popular.

Hey, Tennyson, it's a small world. I checked your site and I wish I had instruments like that. All we have right now is an inexpensive rain gauge. I want something better, but that will have to wait.

It is cold here and tried to snow yesterday, but it didn't get very far. It did snow in town and it may have today. Not sure. It was cold enough to snow today, but it rained instead. Sometimes it can be 34deg out there and it will still rain. Weird.

Parclair, sounds like you live out of Stockton in the peat flats. I know there are other flats north of Sac up out of Chico where they grow a lot of rice. From Stockton on it is flat territory until you get to Red Bluff or Redding. Flat and HOT in the summer.

http://news.discovery.com/earth/dallol-hot-springs.html

Really nice quality pics of one of my favorite volcanes - Dallol

Man... It took me *half an hour* to figure out how to separate and recombine colours in NetPBM. Bet you can all tell how utterly crap I am at the game.

Those shock waves emanating from the root of eruption do not appear to be reported on the EQ trace. Yet a mag1 EQ is equivalent in energy to just 30lbs TNT. How much TNT would be needed to make a shock waves like we see? - rather more than 30 pounds I suspect( ' Henrik? ). 'Action and reaction' means some seismic activity would be detected.
Do tremor recordings report shock waves?

According to a news here in Iceland, this eruption in Eyjafjallajökull is now about 4 times larger then the eruption in GrÃmsfjalli (GrÃmsvötnum) in the year 2004. That was a VEI=3 event.

@Peter Cobbold, That answer would be yes. Shock waves would be reported. Most likely like a spike in a tremor plot. But not as a volcanic tremor like the one we see. The signal would be monolithic (single spike) in nature. It might only be seen on the sensors closest to the eruption. I doubt that my sensor would detect them. Also, the only lower band (Hz) would be recorded, as seismometer cannot record events that happen over 40Hz or 60Hz depending of the type of seismometers.

As the news will talk of grounding flights vs risk management and the Icelandic President cautioning world preparedness, the following link appears to be an internal document about 1981 analysis of the emergency response and citizens reactions to USA Mt. St. Helens 1980 eruption. I believe their was a book written that is more detailed. Google the author.

Thomas F. Saarinen
http://www.eird.org/esp/cdcapra/pdf/eng/doc13413/doc13413-contenido.pdf

@Jon Frimann 134. Aha, so volcanic tremors are oscillatory not a single spike, I had not realised. If such a thing as single tremor were seen in isolation would it have a defined shape; eg frequency,duration,damping etc?? or are tremors too variable to generalise? I am still pondering how to get triangulation information from tremor traces...

Most of the energy of the shockwaves ends up in the air and very little in the ground. Momentum is mass * velocity, energy is 1/2 mass * velocity ^ 2. Lets say 1kg of air reaches nearly the speed of sound lets say 300meters per second, and in return pushes 1000kg of rock the other way at 0.3meters per second (conservation of momentum).

We end up with:

Air energy =
1/2 * 1kg * (300m/s) ^ 2 = 45000kg*m^2/s^2

Rock energy =
1/2 * 1000kg * (0.3m/2) ^2 = 45kg*m^2/s^

The faster the air moves the less energy proportionally is transfered to the earth.

If I was a bored geologist I'd be setting up sensors nearby to record the wave forms resulting from the impulses. Given enough sensors you could likely take the records from the impulses and build a decent model of the inside of the volcano.

@jb 135 Wonderful read. Back in 1980 not all that much was known about pyroclastic flows, tephra and the nature of explosive volcanos. We learn from the past, at least for a generation or two ;-{

@Peter Cobbold, Please read up on earthquakes. Most of your answers are there. Volcanic tremors are different then earthquakes, they cannot be located properly today. Might be in the future, but not at the moment.

In salute to all the great pictures that have been taken, there is this priceless news item. :)

http://baggalutur.is/frettir.php?id=4959

Is it possible that the tremors are caused by a general movement of the glacier? The glacier must always be moving and I would have thought that even a small increase in its speed would result in increased tremor activity. I understand that we don't know what is happening to the magma underneath the volcano but if it has spread to new channels then it might have heated the rock above it causing a small melt in the bottom of the glacier and consequently a reduction in friction and greater speed.

Just a thought from someone who knows nothing about the subject. But posts here are few and far between tonight.

Very opportune the article posted by Boris about he two Soufrière volcanoes. Thank you very much. It shows how much press interference and non-accurate, dubious, information may lead to erroneous evaluation of hazard posed by such events with disastrous consequences. Iâm far from being an expert on the matter, and therefore very interested in your opinion about what may have happened here, or could happen, should further development of this event take place (I mean Katla, etc). How about the evacuation of thousands near Mayon volcano in the Philippines, widely talked about in the press â could that also be the case of misinterpretation of the signs given by the volcano?

This eruption in Eyjafjallajökull has now lasted for one month, with the exception the break that lasted for ~2 days before the eruption in the main crater started.

Yet after all this time, there are no signs of the eruption stopping. It slows down a bit from once in a while. But so far it continues.

#141 Could an icelandic speaker translate the f-word in this google translation? Does it mean what I think it does? ;-D
"Baggalútur possession several photographs taken of the eruption in Eyjafjallajökull morning.

Is damaged it must be told that the images are frámunalega poor."

Frámunalega = exceedingly, extraordinarily, according to my Ice-Eng dictionary. Well, I may be better than many when it comes to the English language, but it is still my third language.

Manual translation: "Baggalútur has in its possession some photos taken of the eruption in Eyj. this morning. / The short of it is that the pix were exceedingly poor. / Baggalútur's photographer shot the pix on a recyclable camera out the window of a small 'plane. The focus is crap, the pictures overexposed and the viewing angle just plain silly - over a passenger sitting beside the photographer. / The worst thing is that the eruption isn't visible at all on the pictures."

I am wondering if one of your knowledgeable people out there can help me?

I have been looking at, and following, the plots from here:
http://hraun.vedur.is/ja/Katla2009/stodvaplott.html

What I would like to know is to what do the three components relate? I see at present that the 1-2Hz at Godabunga has crept up to just under 1400, whereas it as 1000 earlier today. Is this of significance? What is the red 0.5-1.0Hz? (This is normally an earthquake frequency I believe.)

Are these plots showing HTs or quakes? Or both?

Many thanks in anticipation.

Reynir, thank you for the translation. Snort ;-D

Have been checking back for the past few days. Thanks for the updates. A lot of the talk going on here is obvious not for beginners. So I wonder if anyone can recommend one or more good books on volcanism and the chemistry and physics behind it.

World Airways operating CF-6-80 (older engines) also had a problem. Aircraft had to land and at least one engine is off the pylon right now.

http://www.airlineindustryreview.com/latest-volcanic-ash-related-aircra…

CF-6's are work horses but they have the wider clearances. It would seem that both aircraft were in an altitude stratum in a climb or descending as it happened. High exhaust gas temps or cold as the case might be. No middle ground.

The P3 valve on the 757 is what likely malfunctioned. It does it anyway from engine coking (unburned fuel) kind of smoldering. Thats where you get the smoke smell when you first start the airplane its opening and closing and pulling the smell in from the front of the engine. I am assuming that the Thomas Cook 757 had the RB211's on it (Rolls) and not the Pratt 2040 's being a UK operation. But all of the engines work pretty much the same.

The end result though is the same no matter who works on it or whose valve it is. The valve was stuck open, or shut as it kind of flutters open and closed in a cycle to keep the pressurization up. Not unsafe for one to go, but the idea is that the first stage air just behind the first wheel is uncontaminated by fuel (or ash) and its hot so it can keep you warm at altitude, or you can use it to cool if you are on the ground. There is an an airpack on the thing for ground airconditioning using a turbo compressor thats geared to the engine to run it like an air conditioner too.

But the air comes from the outside to the in via the valve which shuts instantly if there is a cabin depressurization. Normal op is that it hits a filter which in turn runs it into the cabin. So you have likely been on the ground and smelt jet fuel before, its only because the engine just got started, there is a lotta smoke on the first start of the day and it just gets sucked in to the clean side. Same idea is that it would be left open by the coking or ash and it could really increase the fuel consumption as its robbing the highly compressed air from inside the turbine section. About 2%.

Ah-But this time they lost the valve and the others were having to keep up with it. Ears popping, sudden head pains. Think of it ramming air into the cabin and then having too much or too little...Or that its fluctuating in great long cycles or short ones. Can you say migraines?

It was enough for an inflight turn back and it was a good decision. Why? Because if one went bad, they all could because the ash was entering all three engines. So if anyone knows the particle sizes floating where these guys were, you now know that glass particles of that size can cause life threatening situations. Anyone want to hazard a guess of what might have happened if they had cut them loose two days earlier?

@Troels - You can check out my books post from last year for some suggestions:

http://scienceblogs.com/eruptions/2009/08/my_favorite_volcano_books.php

We would be tkaing about alot of planes going down and alot of people killed. If there are two planes that suffered damage from the ash I bet ther are more. I knew all along it was a bad idea. Some poeple can jsut be really stpuid and ignorent of the facts like ash is not good for airplanes even in a very small amount.

@Troels, I started with a book call Volcanoes, Earthquakes, and Tsunamis. It is from the "Teach Yourself" series and is by David A. Rothery. It is a pretty good one to start with and I liked it. It is for the general public in that is it not exactly a text book, but it doesn't talk down either. Just a good general book to start with. I got it from Amazon.

Urlesque has a collection of science fair volcanos, cake volcanos, and for you, Frito, a nacho volcano. Rated silly ;-)

http://www.urlesque.com/2010/04/21/23-awesome-science-fair-volcanoes/

>It was enough for an inflight turn back and it was a good decision.

MRK: fairly certain that most aircraft pilots have been given instructions similar to the BA flight manual special update document quoted here a few days ago. Rapid inflight turn back to base is mandatory unless you are heading inbound within affected airspace, close to your destination or another airport.

@David L. 149: my limited understanding is the sub 1 Hz harmonics are related to the movement of magma and the higher frequency (2-4 Hz) harmonics are earthquake activity. Wind and flood water can also contribute, but don't know what frequencies those are likely to show up as.

It would be interesting to process Jon's helicorder data with FFT to see what the frequency domain version looks like. If the raw data were made available, microsoft excel has FFT functions...

Tennyson, get thee to Jon's website and communicate with him directly on implementing F-T data processing. I'm pressure sure that there are online packages specifically for Jon's form of raw data output, you'll have to look for it though. Trying the USGS IRIS site for starters.

Erik, thanks for posting the list of books again. I wrote them down, but I am not sure where I put the list. LOL
I do plan on studying more.

As I'm reading Boris' suggestion, I'm stumbling on certain words. I found I'd bookmarked geology.com which has a dictionary of geologic terms. Rah! Another resource of use in ALLLLLLL those places I've book marked over the years.

Tremors still on the up-swing

Here is today's time lapse of the Mulakot camera. The weather cooperated most of the day (at least until mid-afternoon):

http://www.youtube.com/watch?v=9rsdH6ognW8

@162 Been watching that also. Constantly climbing for about the last 3 hours to news levels.

I personally don't like this quiet earthquake period, there has to be a build up of strain somewhere.

It would be difficult to express my appreciation to all of the Icelanders who have been posting here. Your insights and information are invaluable.

For the thousands of lurkers who I am sure are here as well â thanks.

Larry Stephey
Orlando, Florida

@Dan and @someone The levels have been climbing and yes that energy has to be released somewhere...just can't figure out where EJ will probably wait until no one is looking and then pop her top LOL

Also watching tremor plots... at what point do the experts start getting concerned? It's all very well us saying it's on the up - but when does it start entering a phase that's warrants further attention/reporting?

The water output increased too a couple of hours ago. Could the increase of tremors just be because of the melting and collapsing of the ice cap? Or is something more needed to explain the rise?

Night time is the hardest personally I am dying to get a visual on the tongue of the glacier

@Reece

I suspect that lava is flowing under the ice. It will melt the ice near it but could basically build a sort of tunnel through the ice until it removes enough support and the ice above collapses.

One thing to look for is places where there appear to be depressions in the ice surface that weren't there before.

I can't quite understand any other way that you can have increased harmonic tremor and deflation at the same time. It isn't likely that the magma is flowing back down to the mantle :)

It simply must be erupting magma someplace where we can't see it yet.

Is there a link to the NASA photos that have been taken? I believe they should have some IF photos.

I too await dawn. By this time last night, we were seeing glimmers on the Katla cam. Nada now ;-(

There is a little while to daylight yet:

http://www.daylightmap.com/index.php

Personally the harmonic tremors are purely from around the crater-glacier interactions. From what I can tell there is minimal deep activity at the moment. Implying there is minimal new stuff coming up.
Regarding deflation/tremors if things are subsiding then there will still be tremors. Afterall it is just movement.
Still interesting how the 1-2Hz range has increased in amplitude, I imagine interpreting that is more art than science though.
I think the interesting question will be how the lost mass from both glacier and magma/lava works out in the days ahead. I assume the vulcanologists use some form of Henry's Law. Still even that seems quiet as we aren't seeing the pretty pics like the other night, strombolian I think they called it, where gases bubble up splashing the stuff everywhere.

Curious what the morning brings though. I am betting on a lot of steam.

Just personal opinions...

@renee Here are the NASA pictures. Not very many really.
http://earthobservatory.nasa.gov/NaturalHazards/event.php?id=43253

Sunrise is at about 4:30 in Iceland, and it's only 3:00 now. Dawn in maybe 30/34 minutes, provided there are no clouds.

@Dan Thank you for the link and the sunrise info. I don't think I'll last that long LOL Perhaps if I take my eyes off her for awhile EJ will reveal the secret behind all her HT today. Good Nite All and thank you

When Google translation misses the fine points, like calling 'gos' a soda pop or a drink rather than an eruption, the excellent glossary of geoscience terms found here may bridge the gap:
http://pubs.usgs.gov/of/1995/of95-807/geoicelandic.html
and if you can't find words like 'gosórói' there, you may try here:
http://herdubreid.rhi.hi.is:1026/wordbank/search?changeToWebLanguage=EN

@175: Thanks for your answer Scott. I think it is good to remember the visibility of the crater was zero in the daylight, so I guess clouds are still obscuring any activity.

Tremors still on the rise. As I asked above - at what point is concern raised?

Kris B #178 Thanks for the translation references. I'm sure I will use them!:)

@Helen Leggatt@180 Go to Soquel's site. At the very top he made a movie of the quakes (tremors) leading up to the 1st eruption and on...it was this level of quaking that got everyone's interest. In addition there are other charts and models, some showing the activity through time. Enjoy! :-)

http://islande2010.mbnet.fr/2010/03/eyjafjallajokull-levolution-des-der…

@ parclair - many thanks :) off to visit the site.

Marco Fulle, Stromboi Online, has posted photos from the 19th that clearly demonstrate glacier degradation with continued eruption progress.

We need an update on the condition of the outlet glaciers with the significant uptick in meltwater runoff and tremor activity. Perhaps we can convince him to take a few aeriel photos of the outlet glacier for us here at Eruptions and IMO to view/analyze.

I haven't been able to access meltwater runoff data recently.

http://www.swisseduc.ch/stromboli/perm/iceland/eyafallajokull_20100419-…

*sigh* working late again, bit tired.

@Passerby#185 Thanks for reminding me of the link. Today's pics of the meltwater channels, depressions in the glacier are stunning! Wow.

Get some rest, but first go to Soquel's site. His chart of events vs depth is interesting, increasing incidents, lower depth.

Earth tremor
1.1 km depth2.1M

8.2 km NNE of Skógar 80% quality

Near-realtime GPS data I am looking at:
http://notendur.hi.is/runa/eyja_gps.html

Where are you seeing all this deflation that is mentioned in the posts above???

The majority of the tremor activity is perhaps due to glacier release, floating and subsequent reattachment, that purportedly can occur in cycles with subglacial pooling. However, the crater is considered to be well-drained, so am not sure how much pooling actually exists. Perhaps there is episodic occlusion and release of drainage paths with extruded material. There may also be faulting and minor block failures within the outlet glaciers that is responsible for the continued rise in tremor signal.

The tremor graphs appears to be indicative of accumulating interstitial pressure within deep ice or at the ice-rock interface, which is why I am thinking we may yet see outlet glacier failure (large blocks or ice/rock giving way).

@Passerby

The recommended practice for an aircraft encountering volcanic ash is to turn 180 degrees and leave the area. The problem is you don't know the extent of the cloud and odds are it just gets thicker as you press on. Plus, if you have to re-light an engine, it helps to do it in clean air rather than in ash.

The THEY graph you link has no data since 16 APR. There was a data point posted today here: http://hraun.vedur.is/ja/gps/predorb/theypred.html

That shows it has deflated significantly (look at the UP chart)

Of the ones near the volcano at the page you linked, SVBH shows deflation: http://notendur.hi.is/runa/SVBH.png

STEI shows a general deflation trend, as well as do most of the others: http://notendur.hi.is/runa/STEI_3.png

The tremor continues to rise in areas too far from the glacier to collect any local data from cracking/faulting in the ice. This is deep harmonic tremor and the pattern is consistent across a very large area.

I don't know where the deflation data are. I do know there was at least 1 flood yesterday, possibly 2. (You can see them at the Vodaphone picasa site.)

I answered, Passerby, but apparently included to many links in the reply so it went to the mod bucket.

Basically, look at the graphs you posted and look at the "UP" chart for the stations. Most of them are trending down.

Faulting/cracking/movement of the ice would be picked up close by but those things don't generally result in harmonic tremor that is picked up at long distances. All of the stations in the area are seeing the same pattern of increasing harmonic tremor. That is generally indicative of movement of magma at depth.

Looks like tons of new snow overnight at the Mila fimmvorduhalsi / Ãórólfsfelli cam.

The time-lapsed webcam movie was thrilling. I can't recall when I saw such a vivid example of shifting weather (land-sea winds) fronts and a volcano literally creating it's own weather from steam release (middle of video).

Some of the tremors must be related to the volume of steam cranked out, thermal bumping. Wonder how it compares to geyser tremor graphs.

@189: Precisely why I pointed to the BA guidance document for pilots, providing instructions to do exactly as you describe.

#Passerby 188 http://notendur.hi.is/runa/eyja_gps.html seems like out of date data, the dates are all wrong, is it possible this is static data taken at tha date?

Another indication of deflation is looking at those graphs, look at stations STE2 and SVBH. You will notice they are moving toward each other. STE2 is moving South (negative North movement) and SVBH is moving North (positive North movement). That would indicate the distance between them is shortening which would in turn indicate deflation of the volcano.

#Passerby heh..sorry....this IS static data..slow to get there I guess.

#196 #Passerby hmm..I'm missing.. "I am" I think..:|

@someone. Your question at #194 was first question I asked a week ago, several threads back (though in reference to a different page). Thus began My Lost Week.

Jón, is it the wind what is visible on your helicorder? As I saw it at hraun.vedur.is is 10 m/s at the location near Eyjafjöll.

@Carla #192

Why do you think there is lots of snow at the Ãórólfsfelli cam site? Looks like thick fog / low clouds to me. Of course you might still be right, but (at least) now it's all blurry white.

I've had a LOST MONTH. *sigh* But, maybe as it becomes more regular, I will be able to get stuff done! Maybe:-)

@Monica: The wind has an effect on the helicorders. However the windspeed is quite low at the moment (around 4m/s) so much of the readings would suggest harmonic tremors.

@Jón: It says that the helicorder which is used have a frequenzy range of 4.5-10Hz. But i read somewhere that moving magma is at around 1Hz. Is that true? If so what kind of events gets picked up above 4Hz? Is it mainly larger tremors like EQ´s?

Hello, these days I am very pleased to find all of you here. I am curious to see address of cooling glacial melt on lava flow pattern. If cooling ice melt to quench and deflate of cap, then the flow can be diverted easier then to other chamber? Is this why Katla to respond with possible eruption? Hot goes to cold...? Thank you all, RW

#200 Holger, for a brief moment after first light, the scene was visible and the terrain appeared to be well dusted in snow. Features that looked dark yesterday looked closed-in and more snowy. Right afterwards the mist came in and the view was gone. I haven't seen a decent view since, but it's starting to look up.

@parclair - boy do I know what you mean. I have camped on all the major quakes and on every possible hurricane in the last four years. But I am most interested in volcanoes. I live a few hours from MSH and am a regular AVO watcher. No one I know well understands this, but I feel at home in forums like these. I missed my calling.

@153 Rik and @155 Diane

Thx, I'll look into it :-)

Glimpses of The White Lady from the Hekla webcam through the cloud cover suggest there may be a tall, white plume this morning.

This could be completely wrong, but I have a feeling that 1-2Hz tremor is actually thawing and freezing of the glaciers and those icey bits.

In case your wondering, the chart shows a rough daily correspondence on that frequency (roughly) building in amplitude over the last 2 days as more snow fell. It also reminds me for some reason of compressive beam stress. eg. expansion/contraction in the ice.

Ideas anyway.

Yesterday was another day of back-and-forth between wind-directions. Some Holes in the clouds allowed to see the ash/steam plume that has decreased in size over the last days:

http://www.youtube.com/watch?v=GzuXj1tkvdQ

Good morning!

Nothing much is happening with Eyjafjallafjökull but at 5:30 this morning (GMT) Magnús Tumi was quoted as saying that the activity shows no signs of abating either.

The initial phase of the 1821 eruption lasted for something like 2 weeks, a long lull followed and 6 mos later the eruption started again full force.

Here's a video that just appeared on mbl.is:

http://www.mbl.is/mm/frettir/innlent/2010/04/22/nottin_roleg_i_nagrenni…

@Philipp (#209) that's an interesting video because you see how clouds move left to right and the vapor/ash plume moves in the opposite sense. An outstandingly fine example of different wind directions at different altitudes even over a vertical distance of at best a couple of hundreds of meters. That's what I tried to explain the other day, that you can have extreme variations in meteorological conditions (wind, cloud, humidity) over rather small vertical distances ...

Quite amazing that over the past 24 hours, tremor seems to have touched the highest levels since the onset of this eruptive episode, and at the same time the eruptive activity has been going on relatively calmly. Though I am not convinced the heightened tremor is due to glacial melting - one would have to see where the tremor source is located. That's something that can indeed be determined, but it requires extremely meticulous analysis because different sources of tremor can be superimposed, creating a "false" location because software aimed at locating the tremor source - called "R2 method" - sort of creates an average of all signals it receives (the fortunate among you who have access to AGU on-line journals can take a look here: www.agu.org/pubs/crossref/2006/2005GL025177.shtml). That means, if there is a tremor source at 8 km depth and another at 2 km depth, it simulates a single source at 5 km depth, which obviously is an error. In any case, if the source of the tremor is within the volcano, anything related to the glacier can be excluded.

I fear this tremor talk is not very easy to understand but if someone is interested in specific details I will be glad to explain some further!

Tremors are indeed very interesting and I suspect that if given the chance to study them and have a deeper understanding as well as more accurate (detailed) measurments would give a much more clear view of what was actually going on beneath Eyafjalla and possibly even predict what is about to come to some extent.

But I guess that all you volcanologists and geologists would give your right arms right now to get a peek inside the ongoing mechanics of Eyaf am I right? :-)

@#209 What is also interesting in this video is the greatly increased melt water flow from Gigjökull during the afternoon. From MÃla Ãórólfsfelli webcam, this morning at 0900 UTC the flow seems to be greatly diminished.

Ãórólfsfelli now shows a dense and quite vigorous vapor plume, apparently with some ash, and dark rivulets of meltwater coming down through the GÃgjökull valley

Are there any single vulcanologists around? :)

Probably but EJ is a strict mistress She becomes addictive and demands all your free time LOL

According to the weather forecast the local wind direction is due to turn to South Easterly on Friday. This could mean ash fall for Reykjavik if the eruption is throwing up ash at that time.

@ Jamie Z (217)

ReykjavÃk is more than 100 km away. The ash is not going to be blown that far.

Ash fall predictions Friday to Sunday:
http://www.vedur.is/media/jar/myndsafn/large/VORIS_2_0_1b_aska_20100421…

@217 Finally some attention to the locals. :-) Anyway my dad isn't looking forward if that happens. But prepared.

I still have a few questions which I have posted earlier but not had the chance to see any answer. Maybe its possible now.

1. I can imagine because of the frequency of an eruption taking place its difficult to collect any data to excavate a behavior analysis, a moderate prediction methodology if you want to call it that. Is this because of lack of funding? Lack of cooperation from various entities, although I see in these blogs allot of people willing to either 1. learn more instead being adapted to sensational news setting or 2. share information to create a sound analysis. What I am querying here is some search to create a platform of experts to be able to work across boarders, a unit which work with all the weather institutes and government health institutes to not only create a firm governance for analysis (we have now seen the ash effects many countries) but also to aviation groups. Sort of an advisory setup with clear analysis versa risk assessment for aviation. Its not the first time an ash cloud has effected aviation. There are many incidents with planes having issues with the ash but not officially reported probably to avoid panic in the volatile economic setup.

I am so surprised that we are so busy, officially, to work together for saving the climate but we see again a clear role of economics ruling. We need to find that balance. Overall I think that the honor of many people (like you) and official institutions, is important and not just being blamed for economic malaise. We have a chance here for guys like you to be taken seriously.

2. I am missing some sort of an overview of trend analysis and a typical behavior pattern (me as being an interested amateur). I have been looking for some data and even seen some discrepancy. I see very well documented details of former eruptions which is in its self very useful. But using a trend analysis (looking at history), looking at a normal behavior pattern when an eruption takes place and a list of tools and measurements used to monitor (and where data comes from) could not help for an overall view of matters but also be used to warn or even calm people.

Maybe I am asking too much and hope these questions dont really irritate :-) the specialists here.

cheers
Eric

"And we can thank Iceland for one thing: difficult names."

We can call them all "Hekla" then - how's that? One thing you can thank them for not exporting is that mummified shark meat; give me a volcano any day!

@Eric #219: There is a lot of work studying the eruptive characteristics of volcanoes, with perhaps the Italian volcanoes receiving the most attention. It has been almost 20 years since vulcanologists had confidently predicted the eruption of Pinatubo, but the learning process is very slow. Any seeming patterns in time are usually only imagined. What I see at the moment are efforts to look for clues of changing activity by quantifying the relative amounts of various gases in the magma or to look for patterns in the degassing (is the amount of gas being released increasing). As far as the measurement of amount of gas released goes, that remains a pretty tough challenge; current estimation techniques have very large errors and the gas output can vary a lot from day to day even if there is no pending eruption.

Shark meat with a BrennivÃn chaser. Sure clears your sinuses!

:o)

@Eric (#219) - one problem with this specific volcano is that its history is not very well documented. There have been few eruptions in historical time, and only one of them (the most recent, 1821-1823) seems to be documented in appreciable detail. That's not much you can build a statistical analysis on. Even at Etna, where we have 64 well defined flank and countless summit eruptions for the past 400 years, experts in statistics still make a face saying "that's not a lot of data".

Furthermore, volcanoes tend to surprise. There are volcanoes which, since many centuries, have been erupting in a determined way. Take Kelut (or Kelud) on the Indonesian island of Java. All historically documented eruptions have been violently explosive, and many have caused fatalities. This was also so in 1901, 1919, 1951, 1966, and 1990. Then, in 2007, Kelut woke up again, produced intense seismic activity, 100,000 people were evacuated. The eruption that started then was totally non-explosive, but rather built up a lava dome within Kelut's crater. There was no explosion at all, just quiet lava extrusion. And there was no way saying that the eruption was going to go like this, everybody was 100 per cent convinced it was going to be, as usual, a powerful explosive event.

Or Mayon in the Philippines, at the end of 2009? Normally this volcano produces lava flows but also explosive activity and pyroclastic flows (avalanches of hot volcanic gas mixed with fragments of volcanic rock, the most deadly thing a volcano can do at all). There was strong seismic activity in December 2009, the lava emission started and everybody waited for the powerful explosive phase of the eruption and pyroclastic flows. It never happened. Just on New Year's Eve, the eruption suddenly ended.

This is to tell you (and all those who may have had a few doubts about some of my earlier comments) how little way there is of telling how a volcano will behave. Certainly there are things which are much more likely than others, but the cases outlined above show that sometimes the least likely can happen. I guess even with Kelut's documented eruption history, which goes back to the 14th century and encompasses about 30 eruptions, whatever statistical approach would have failed to envisage a purely effusive eruption after all the explosive events.

Could that be a sudden gust of wind in Jón's helicorder?
http://www.simnet.is/jonfr500/earthquake/tremoren.htm

Guess what, we are lucky the human race was not wiped out ;P

http://www.guardian.co.uk/world/2010/apr/21/iceland-volcano-ash-extinct…

Thanks Anna (#218). Another interesting map from Icelandic Met Office. They must be working hard.

I'm guessing it says those are accumulations of at least 1mm. Do you know if that is based on current output? Is there just no real danger of significant ash fall reaching Reykjavik from this eruption?

Still, bad news for those towns in the affected area.

Only 6m/s so that would not produce such an activity since the 10m/s yesterday showed less.

Maybe ice on the move?

@224:

No, for weather info look at the link at the bottom of the helicorders page... wind speed 6,3 m/sec, 22,68 kph.. nothing spectacular...

What's up with this large increase in tremor? since there is no plume to be seen on any webcam... yet another mudflow perhaps?

And then the tremor stopped suddenly...Went on for approx 30min..

But would a mudflow create such a "noise"? It would have to be quite big.

I think a mudflow would affect, unless very large, only seismometers within not too much distance from it. Also it would probably be more gradual in fading in and out, although it's not that the last rise in wave amplitude wasn't gradual in that.

If it wasn't the wind (I know there are wind readings there... but to be sure I was asking confirmation, one can never know), nor tremors or mudflows, then it might have been local cultural noise. One indicator of this is the sudden/abrupt "development" of waveforms, which however would be hard to see on that helicorder as it uses a very compressed X scale.

A spectrum view of the seismic data would help much in identifying the noise source, by the way. It would be great if Jón added it someday soon.

(re #225) Poor Simon Winchester! Little does he realise that his own pen betrays that in terms of learning, his surname has as much resemblance to Winchester School as Eyjafjallajökull has to Toba in volcanic terms. I would indeed like to see this mountain of his mountain: "Mt Toba... ...The relics of this mountain today are no more than a very large and beautiful lake, 60 miles long and half a mile deep"

Oh dear! xD

http://www.armageddononline.org/known-super-volcanoes.html

Found a great site that summarized all the known supervolcanoes on earth. Some like the New Mexico one I had not heard of...

That was one of the more strange ones..

Boris or Jón...Any idea of what it might have been?

@ Jamie Z #266

First off, I'm not an expert. But I think it's safe to say that the Met Office is only predicting where the ash will fall, not how much ash will fall.

I don't think ReykjavÃk is in much danger from ash. Unless the volcano starts spewing out massive amounts of ash and the weather conditions get very freaky.

Sorry if my language broke down earlier, but I was laughing so hard at Simon Winchester's vision of a "Mt Toba" (see #225). With an average gradient of 20 degrees and using the dimmension he gave, such a mountain would have been 17km (10½ miles) high...

Take a look at some of the links over at the Volcanism Blog:
volcanism.wordpress.com/2010/04/21/an-eyjafjallajokull-miscellany/

There's some hilarious stuff in there. Another Simon (Jenkins not Winchester) proudly screaming out his ignorance on The Guardian, for example. And a lovely video called the "Iceland Volcano Mispronunciation Video". Do visit.

@Daniel #233, what are you referring to?

Dont think it has been said yet: Gleðilegt sumar, to the lovely people of Iceland!

#223 If you want a more scientific view of the varieties of massive volcanism go to: Large Igneous Provinces http://www.largeigneousprovinces.org/index.html
Using the "super volcano" label suggests something unnatural whereas this process is quite natural over geological time. At the end of each month a new research article is added to the site. Discovery Channel probably would not approve of its reasonable, scientific demeanor.

Quotes: "Earth history is punctuated by events during which large volumes of mafic magmas were generated and emplaced by processes unrelated to ânormalâ sea-floor spreading and subduction. These Large Igneous Provinces (LIPs) are best preserved in the Mesozoic and Cenozoic where they occur as continental flood basalts, volcanic rifted margins, oceanic plateaus, ocean basin flood basalts, submarine ridges, and seamount chains. Felsic rocks may also be represented.

Many LIPs can be linked to regional-scale uplift, continental rifting and breakup, and climatic shifts.

Helicorders going crazy again although there is no increase in windspeed (only 1m/s more)...

What could be the cause of this?

Jón, are you out there banging on it with a hammer?

Woops. My comment #238 was meant for #233 scarlet pumpernickel. Apologies.

Sit, thank you and gleðilegt sumar to you!

@Boris... Eyjafjallajökull.. Hey I can actually say that word now.. lol The video is hillarious..

@Daniel Do you have the link for Jon's helicorders?Thanks in advance.

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

http://www.simnet.is/jonfr500/earthquake/tremoren.htm

Here you go Mattlee

Go to simnet.is/jonfr500/earthquake/tremoren

@Boris great video on the mispronunciations, i loved when the guy said "I hope i'm saying this right....v-o-l-c-a-n-o".

Sorry..You need to have "www" also...And "tremoren.htm" at the end.

On Mulakot webcam there is no sign of anything. no plume no nothing..Some steam only it seems.

On Vodaphone pictures there is no increase in mud or water as far as i can see.

She is completely quiet..Except for the tremors which is through the roof at the moment. And the wind is quite low (7m/s). Tremors seem to go in waves..High activity then nothing then alot again..

Is she clogged up? Could it be that it is building up pressure inside?

@Daniel - Brilliant. Thanks

Or is it man made? Can it be as simple as a tractor running over it? :))

30 min interval on both occasions.

I retract my #249 comment. Strange spike again...

@Anna. Thank you! 20,000km away in Australia at the moment, but will hopefully be visiting again before Summer is over :)

My geophone has it main frequency at 4.5Hz, it can go up to 60Hz and down to 1Hz properly. I lowpass filter the plots at 5Hz so everything above that gets cut, but is not necessary gone from the plots. Currently there is some man made noise on my plots, that are the spikes that appear.

Boris! Re "our mutual acquaintanceâ Simon Jenkis - Dorothy Sayers once let one of her characters say âSome people can be funny without being vulgar, some both funny and vulgar. I recommend you be either.â

@pyromacer Are these not different, more alike flood basalts under the sea. The supervolcano structure is more of a caldera formation while the ones you mention are more just outpours under the ocean?

Hahahaha Henrik (#253) - in comparison with Jenkins, Simon Winchester is rather enjoyable to read!

Yup, Jón's note on man-made noise makes sense. Tremor amplitudes have conspicuously decreased since early today on the graps at hraun.vedur.is/ja/Katla2009/gosplott.html

The dramatic peak in tremor amplitude in the past 24 hours remains a bit mysterious, though also here it is necessary to apply caution because it can mean a great variety of things. sSometimes tremor amplitude is directly correlated with the style and intensity of eruptive activity, sometimes with the volume, depth and speed of subsurface magma movement, sometimes with the amount of gas bubbles forming in a magma, sometimes it depends on whether gas bubbles rise slower or faster than the ascending magma ... it's a hell of a mess. We'd really need to see the depth of the tremor source, the so-called "centroid", in order to better understand. And that's a type of data that's not made public but is reserved for the interpretation of experts in volcano seismology and eventually finds its way into scientific publications.

Thanks for the link, Boris Behncke at #236. The pieces by Simon Jenkins in The Grauniad and Frank Furedi's scribble are truly hilarious. Jenkins is absolutely shredded in the follow-up comments where the length, depth and breadth of his ignorance are enumerated.

The Volcanism blog comments on Frank Furedi:

Frank Furedi at the generally loathsome Spiked Online: âI claim no authority to say anything of value about the risks posed by volcanic ash clouds to flying aircraftâ, he says, but surprisingly he does not then shut up.

So true, and this expert on decision-making doesn't understand how the airlines blocked setting of "safe" limits years ago, so much of the uncertainty is of their airlines' making.

Furedi, with the arrogance of the ingnorant opines:

it is evident to me that the reluctance to lift the ban on air traffic in Europe is motivated by worst-case thinking rather than rigorous risk assessment.

justifying this with:

... fears that particles in the ash cloud could cause aeroplane engines to shut down automatically mutated into a conclusion that this would happen.

Um no, they didn't. It would be accurate to say that knowledge that particles in volcanic ash clouds have caused serious damage to aeroplane engines including shutdowns led to a conclusion that it would be prudent to take the risk very, very seriously.

I would like to thank you all for the interesting informations and links i found in this great blog.

i don't know if it's of your interest, but here http://cetemps.aquila.infn.it/Cetemps/it/images/sitocet/vulcano/prel_re… you can find an observation in italy, of the ashes related to this eruption.

@Jon - was the tractor in the cam the noise?!!

@Helen Leggatt, given the amount of noise on my sensor at the moment. It was part of it (spikes, etc).

At the moment I am getting some other noise signal that I am not quite sure what it. Might be washing machine, as I do record the noise from the all the time given the geophone location.

If anyone is feeling a bit bored, I have a bunch of links that I've collected, but not had an opportunity to categorise or date:

http://eyjafjallajokull.pbworks.com/

Anyone can create a login for PBWorks and edit the page so if you do fancy helping out with organising the links and adding other interesting ones I've missed, please be my guest. :)

Unfortunately I'm in the middle of both a huge project with an evil, evil deadline *and* a grant proposal, so I have very little Eyjafjallajokull time. But it is great to have everyone on this blog keeping me updated with tremor, plume activity and such. Thank you!

@SamC I still think this ash thing is a bit overated. They keep mentioning the 1980s 747 which had 4 engines shut down, but that one, did it go right through a giant plume, that's like taking a plane right through the plume as it comes off the volcano in Iceland. And is the plume even over europe in the thickness it was modelled, since they are using a nuclear war ash pattern to model the plume on a computer. This computer modelling thing needs to be stopped, we actually need to use real observations instead to make predictions, not this fantasy weather computer.

How do planes fly around Sicily? They only close Catania airport when ash is almost falling on the airport don't they lol? When I went to Sicily I could see Etna pumping out ash hard, but the plane had no problems at all lol.

The coastguard flew over the crater yesterday and took these radar-type pictures:

http://www.mbl.is/mm/frettir/innlent/2010/04/22/reykjavikurflugvollur_k…

In the pic to the left they have pasted the ReykjavÃk domestic airport over the crater to give an idea of its size.

(kind of fitting they chose an airport picture for the purpose!)

@Scarlet #261 there have been several aircraft, including some Finnish Hornets, some NATO F16s (iirc), at least one helicopter flying over the North Sea, and some passenger jets (at least two that I recall seeing definite info on, and two more that are unconfirmed) that have had problems with the ash.

The threat to aircraft from ash is not imaginary. The fact that we can't see the ash doesn't change the damage it does to aircraft engines, sensors, etc. Yes, everyone is pointing at Flight 9 as a dramatic example of what can go wrong when an aircraft flies through an ash cloud, but don't let that deceive you. The less dramatic effects can be just as problematic, not least from the increased need for maintenance messing up airlines' schedules.

Planes fly around ash clouds elsewhere in the world all the time, but we are neither used to nor prepared for the kind of extensive ash coverage that we experienced (and likely will experience again) here in Europe. I am sure we'll get better at it as we have more practice, but it's very, very important not to underestimate the dangers faced by aircraft in an ashy atmosphere.

Looking at the radarimage there are 4 vents. I thought there was only 3? When did the small center vent open?

@261 Didn't a Thomas Cook Boeing 757 run into ash yesterday in UK airspace causing a problem with one of the engines?

http://news.bbc.co.uk/2/hi/europe/8635820.stm

Iceland looks like Yasur at the moment lol

I am not an expert but I noticed that the last two occasions there was a small earthquake the tremors dropped immediately afterwards. Compare the tremor plots to the quake table for the area. You can see the effect is immediate.

Scarlet (#261) - the encounters of Boeing 747 jets with volcanic ash clouds in 1982 and 1989 did not occur straight over the volcanoes but hundreds of kilometers away.

At Etna when there's ash emission during bad visibility (cloud cover) all air traffic in the area is shut down. Air traffic is allowed when an ash plume is well visible and thus can be easily avoided. Luckily at Etna the long-lived ash plumes of the 2001 and 2002-2003 eruptions were exceptional, normally ash emissions at this volcano last rarely longer than a few hours.

@Daniel (#264) - that feature which looks like a 4th vent may be a collapse depression in the glacier. But it might be another vent, though in this case it doesn't really change the significance of the eruption whether there's 3 or 4 vents in the summit caldera; many explosive eruptions occur from changing vent locations in generally the same area.

@263 Suw but we don't even know where the ash is because it was only modeled on a computer. No tests were conducted to actually check the real life. That's why Lufthansa and KLM started doing tests. If ash was such an issue, why can we fly around Etna and other areas in the world like Alaska/Indonesia/Kamchatka where there is ash almost all the time. How can planes land near Vanuatu as Ambrym and others are always pumping out gases and ash often. I think if you flew directly pretty close to the source then it would be a problem or in the plume as it tracked away from the volcano. But we don't even know where it went or how thick it is because the lasers or other systems can't measure it properly. The eruption was quite small in the scale of things.

As for the NATO F16's if there is damage why won't they tell us where this occurred or show pictures, that sounded like UK covering itself. It's not a state secret where F16s fly, you can hear them and often see them.

North Sea would be directly in the plume's direction so I guess these may be a problem.

Was the 757 confirmed to have a problem due to ash, was it inspected, planes all over the world have issues with engines all the time, just because an engine has a problem doesn't mean it's ash http://www.abc.net.au/news/stories/2009/12/19/2776559.htm

Daniel #264

The headline reads: "You could fit ReykjavÃk Airport into the main crater".

I'm not sure what they mean by that.

@265 "Ash" was faulty air con according to this report

http://www.avherald.com/h?article=42a697d8&opt=0

@261 Yes..

here is the link

http://www.youtube.com/watch?v=1Iku6SoaKH4

And thanks to all answering some of my questions. Although how do we make sure we can move this to a more suitable decision making process cross countries and provide " money proof", KIS (keep it simple) for example for aviation?

Love monitoring the comments in this blog..

Scarlet Pumpernickel #261

This is not an either or thing.

They use a model and observation.

I imagine one will need as much observation as is possible to see how well the model holds up. A model presumably evolves.

Gleðilegt sumar to all my Icelandic friends!

@Boris

Hi, So was the Iceland Ash different to Etna's since according this report Etna's ash dissipated

http://geology.com/nasa/monitoring-volcanoes.shtml

Can't see much difference in the Etna plume?

http://www.nasa.gov/topics/earth/features/iceland-volcano-plume.html

Did the computer program make the plume go around europe, since the satellite looks different?

@269 ... with the 757, I gather that the problem was related to a air bleed blockage ... it occurred just after encountering the ash cloud ... but the crew did not shut down the engine ... they returned to Manchester airport.

See here: http://www.airlineindustryreview.com/latest-volcanic-ash-related-aircra…

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=43250

Did the planes all stop flying from this sand storm?

Scarlet Pumpernickel #269

The KLM and Lufthansa tests were highly publicized. The UK Met Office had run tests prior to that.

@Anna I think europe was just annoyed that UK was trying to run the show. And maybe they had it all wrong? That's why they were starting to crack it lol?

Why does UK MET get to run it? Doesn't Europe have monitoring equipment either?

@scarlet #269

Where are you getting the idea that no tests are being done? NERC have flew two flights in planes specifically fitted out with specialist measuring equipment last week:

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

And they continue to fly repeatedly:

www.nerc.ac.uk/press/releases/2010/18-volcanicplume.asp

I have so far seen no evidence that the Met Office models are inaccurate, and whilst I wish that they would be more open with the data they are gathering, I currently see no reason to doubt their methods.

The Belgian Nato F16 story is here:

www.google.com/hostednews/ap/article/ALeqM5gOf6EkFL_a2lZK_hHNlDWEig3uXw…

It is understandable that they don't wish to go into too much detail, but the Finnish Hornet incident came with pictures:

www.flightglobal.com/articles/2010/04/16/340727/pictures-finnish-f-18-e…

The helicopter story is here:

news.bbc.co.uk/1/hi/scotland/north_east/8634712.stm

I don't have time to dig out links for the other stories, but i know some of them were posted in comments on this blog.

Key things to remember:

It doesn't take much ash to cause a problem
The EU has a very, very busy airspace - just take a look at www.flightradar24.com/

Yes, there are holes in our knowledge about exactly what level of ash is safe to fly through, the exact extent of the ash cloud, and its exact composition, but we have enough information to know that we have a problem. Reports of ash damaged aircraft should not be dismissed out of hand and just routine events, as they are clearly not.

http://www.telegraph.co.uk/news/7608722/Volcanic-ash-cloud-Met-Office-b…

Computer models cause problems IMHO

http://news.bbc.co.uk/2/hi/science/nature/8027798.stm

Latest ash report... Area is shrinking but low level transport is carrying far back to the west. My question? What do they do if it or another erupts again? If they are questioning why it was done in the first place, think what they will say on about it on the second. Public pressure will certainly get to the point of someone going up, then not coming back.

If it was the airlines that pushed for the VAAC in the first place, then why did they circumvent their own criterias on the second place?

Money....

http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271936020.png

@scarlet #279

The UK Met Office doesn't run the show at all - Eurocontrol has responsibility for European air spaces. The UK Met Office, the Volcanic Ash Advisory Centres and other organisations all work together. But Eurocontrol actually is in charge of making the decision.

So no, nothing to do with nationalistic issues at all.

#277 Sand and ash are different - they have very different properties. You can't compare aircraft behaviour in sand with its behaviour in ash, just as you can't compare sand storms with bird strikes. Ash is actually significantly more dangerous than sand.

http://finchannel.com/news_flash/World/62436_Global_warming_blamed_for_…

This is getting crazier every day. Does the NAO not exist anymore?

I am seeing part of the plume on Vodafone web cams, it looks bigger then yesterday. But it still white, at least it appears to be.

http://www.flightglobal.com/articles/2010/04/19/340802/ash-cloud-nato-u…

Maybe eventually NATO will find out which jet it was, they might have to re-ask USA again??

One thing is for sure the E.U needs to formulate some sort of protocol for possible future eruptions of Icelandic volcanoes.
I've just benn reading about Askja volcano, scary stuff.
http://en.wikipedia.org/wiki/Askja

@ SP Instead of sitting on your high horse chucking your opinions around about how "fantasy weather computers" shouldn't be trusted, why don't you find out more for yourself about what the aviation sector [i.e. not a forum of incredibly patient and informative volcanologists] know about global volcano hazards and what it is that makes experts in the aviation sector appraise ash-cloud risks more highly than you?

Hint: Please try looking a little deeper than media spin

http://www2.icao.int/en/anb/met-aim/met/iavwopsg/Documents/Forms/AllIte…

Re 284 - The changing wind patterns are a fact. We ought to be getting predominantly south westerly winds here in UK. We seem to be getting more azores high and less icelandic low of late.

News/photo link from 262:
http://www.mbl.is/mm/frettir/innlent/2010/04/22/reykjavikurflugvollur_k…

Translate it though Google, look at the photo and description.

Worth noting, cautiously. Earlier photo for comparison would be useful; these depressions may be a pre-existing feature.

Or vice versa. Sorry.

@Zander What about Hekla, also another monster waiting to awake
http://en.wikipedia.org/wiki/Hekla

@Eddie This is really worth a read http://www.amazon.com/Little-Ice-Age-Climate-1300-1850/dp/0465022723/re… wind patterns change over time all the time. The types of weather over the UK over the last 1000 years have been quiet remarkable. NAO moves every few decades and changes the patterns, though sometimes it moves more or less often.

Has streamflow just increased here: http://eldgos.mila.is/eyjafjallajokull-fra-fimmvorduhalsi/

Or is it just my weary eyes?

@Jón I was looking at the Ãórólfsfelli cam and noticing how the lower cloud appeared to be moving in a different direction to the higher cloud. I speculated to myself that this may be because the low cloud is in the lee of a large plume, causing the wind to swirl back on itself somewhat.

Now i think the plume itself is beginning to show on that cam too, it does appear to be very wide by recent standards.

@ Eddie - The actions of the North Atlantic Oscillation (NAO), a "seesaw" of atmospheric pressure between a persistent high over the Azores and an equally prevalent low over Iceland. Using charts and maps, Fagan (the book above) showed how the NAO governs the position and strength of the North Atlantic storm track and thus Europe's rainfall. The NAO index shows the constant shifts in the oscillation between these two areas, with a high NAO index indicating low pressure around Iceland and high pressure in the Azores, a condition producing westerly winds, powerful storms, more summer rains, mild winters, and dry conditions in southern Europe. A low NAO index signaled high pressure around Iceland, low pressure in the Azores, weaker westerlies, much colder winters, with cold air flowing from the north and east. The exact reasons for the shifts in the NAO result from a complex interaction between sea-surface temperatures, the Gulf Stream, distribution of sea ice, and solar energy output.

For eg between 1300 and 1850 it was an era of dramatic climatic shifts, cycles of intensely cold winters and easterly winds alternating with periods of heavy spring and early summer rains, mild winters, and frequent and often devastating Atlantic storms as well as periods of droughts, light northeasterly winds, and intense summer heat. The Little Ice Age was "an endless zigzag of climatic shifts," few lasting more than 25 years or so.

Was this also "Global Warming"?

In 1783 when Laki erupted, did Global warming push the vog over europe?

Would just like to extend a Thank you to Boris Behncke, Jón Frimann and all the other professionals or highly knowledgeable amateurs who actually have the patience to explain in laymans terms when we post our questions and observations. :-)

Check out the Poro cam look different again larger loss of ice perhaps

New post for today:
http://scienceblogs.com/eruptions/2010/04/eyjafjallajokull_flight_cance…

@ Fireman

Gleðilegt sumar to you!

Hehe its funny. An official today welcomed summer i believe on Iceland. And then you look at Katla cam and it seems to be a direct feed from one of the most harsh arctic landscapes on the planet. :)

@Jón: the water flow at the Ãórólfsfelli cam has been increasing all day, like yesterday. I don't know enough of the local temp changes to guesstimate whether this is caused by the melting nightly snowfall, or an increase of the melt water flow from the glacier. The same thing was apparent yesterday: visibly more water in the flood channels in the afternoon. One explanation could be collapsing parts of the glacier damming the flow causing cyclicity - only this would most likely be random, not every afternoon, thank-you-very-much.

Do you guys think that the glacier itself could weaken to the point that it will begin calving?

And what effect would that have on EF volcano? The release or down pressure enough to make a difference or would it be insignificant?

Daniel,

Yes, today is the third Thursday of April, officially the First Day of Summer in Iceland and a public holiday with parades for the children and all. It's customary to exchange gifts on this day.

Real summer will probably arrive in about 6 weeks :)

@303 Anna It seems the people of Iceland have a different definition of summer than I do here in Florida. lol ;>)

Ill join in the celebration then..Too bad im not on Iceland..:)

Gleðilegt sumar allir frá Ãslandi!

Oh-oh. The plume is again rising high, but it looks like steam this time: quite white in color. Also, it looks like zero-wind conditions at the top. (Except upwards - that heat must cause one hell of a draft...)

@ Dan: I didn't know you had summers in Florida -- I thought it was a mono-season state :)

@ Daniel, thanks!

new blog as of about an hour ago.

@eddie. Sorry have to disagree about wind direction at this time of year. We always have this easterly rotation at this time of year here in Ireland. We call it summer! It is usually the last two weeks in April and the first one in May. Then it happens again in late October. That one is the Indian summer. In between it is either the warm wet season or the cold wet season depending on which side of May you are.

@ Scarlet Pumpernickle 298. The NAO shows 30-year periodicity,and that cycle is on the cusp of change now. So we can expect in UK and northern europe more 'negative' winters over next 30 years compared with the past 30 years. So repeats of snow in UK and storms in Madeira are on the cards.

@Peter Cobbold Solar Cycle 25 will be interesting, especially if it is combined with a few large volcanoes, we have not had many major eruptions in the last century

http://www.eurekalert.org/pub_releases/2010-04/iop-lbs040910.php

http://www.dailymail.co.uk/sciencetech/article-1267757/Britain-facing-b…

The pixelation on the Val cam was so strong I thought I was looking at a Van Gogh.
Seems better now

http://en.vedur.is/earthquakes-and-volcanism/earthquakes/myrdalsjokull/

New earthquake near EYJ

Does anyone know how far lapilli from the eruption is likely to have spread?

Great posty, been quite a while since I came across an article with good ideas that i didnt know about.

Things you mentioned a lot of sense. But, think about this, what happens if you offered a little more? I mean, I don't tend to teach the way to write your site, however what if you added something which can easily get peoples particular attention? Just simply like a video clip or perhaps a snapshot or even 2 to get your readers psyched concerning what you are talking about.

Just stumbled upon this through a friends post..great idea and amazing talent here..

Fantastic stuff!! I will need a bit of time to entertain the blog!