Thursday Throwdown: More volcano news than I can list here

I'm still playing catch-up after my week in the desert, so I've seen a lot of articles I've wanted to mention ... but a certain other volcano has taken up a lot of my time. However, I will attempt to make amends for that now.

By the way, would you believe Ubehebe Crater was closed? How do they close a volcano, anyway? However, I did get a great snap of a welded tuff on the road outside of Shoshone, CA.

A strongly welded tuff near Shoshone, CA. The dark interior is remelted volcanic ash/tephra surrounded by less welded pink tuff with abundant pumice clasts. Denison student David Sisak is on the left for scale.

More like this

Hard to believe, but there is other volcano-related news in the world ... So, with all deference to Eyjafjallajokull, here it is: Dome collapse on Colima in Mexico, image taken March 30, 2010. The new Smithsonian/USGS GVP Weekly Volcano Activity Report was issued, with news about increasing signs…
Catching up with some news: Anatahan erupting in the northern Mariana Islands in 2003. I ran across this article right before I got sick, but its been popping up around the interwebs (and is pretty interesting). It details a study in Molecular Ecology that suggests that populations of caribou in…
Mt. Saint Helens in Washington state, USA I'm back from my sojourn to New England and its time to play catch up. First things first! There has been a lot of chatter in my inbox and on the comments here at Eruptions about the study/press release from Graham Hill's research group talking about the…
News! Colima in Mexico erupting in 2008. The current activity at Eyjafjallajökull is more-or-less unchanged, with strombolian activity producing a 3-4 km tall ash-and-steam plume and the lava flows at the crater moving northward towards the GÃgjökull glacier. You can check out an extensive page…

Those Soufrière Hills pictures are now both nominated for the 'Best Volcano Picture' of 2010 ^_^ . I hope someone on that plane made a video of the eruption. I looked for it on youtube, but couldn't find it (yet). Did find this however:

By Gijs de Reijke (not verified) on 25 Mar 2010 #permalink

Just wondering - is that scale metric or Imperial Sisaks?

Fuji made a bit of a run towards the end, but Tristan de Cunha had too much of a lead :)

Erik, this is the "left coast" after all, and they probably closed the crater to keep people out of there and also to keep anyone from leaving trash and defacing it. If someone got hurt there and they had to rescue them, that is another reason they may have closed it. Then there is the fact that they have designated a bunch of land in S CA a wilderness area so that could be the reason. I could say a lot more, but I will refrain. It just burns me that they close so much land to "save it for our children." Enough said.

I heard there were new developements on Eyjaf. Do you know anything about that? In the mean time, I will check the thread.

@Diane, there seems to have been a new lobe of lava moving more or less parallel to the first one, and obviously it encountered snow, generating a large vapor plume. If this flow continues it might also reach the deep gorge that has captured the first flow and we might again see some of those secondary phreatomagmatic explosions when lava drops over the cliff and mixes with snow.
Apart from that the eruption appears very much at the same levels as yesterday.
An updated map of the lava flow has been posted at Nordvulk:

Sorry Erik but I don't buy the theory behind the extinction that opened the door for the Dinosaurs.

Ten times the amount of CO2 as today does not cause a hot house.
You can read here why that is the case.…

So the extinction that took place must have had other causes than CO2.

Claim defied, case closed?
Or is this another piece of AGW propaganda!

By R. de Haan (not verified) on 25 Mar 2010 #permalink

Ubehebe Crater, road-access closures due to inclement weather, road damage and ongoing repairs.

Triassic-Jurassic extinction, CAMP flood basalts, and the CO2 concept defuzzing:

Elevated CO2 and temperatures changed climate, but more importantly, temperature increases reduced dissolved gases in the oceans, while cloud and sulfate aerosol cover reduced ambient light levels. Marine chemistry shifted abruptly (marine biocalcification crisis), and these factors probably contributed to the significant die-off of marine organisms during the extinction event.

In the terrestrial environment, abrupt shift (<10 KY) in temperature and precipitation created hot, dry climate conditions, as O2 levels declined. Most flowering plants died out.

Triassic megafauna with inefficient lungs and without access to sufficient water and food eventually perished, while smaller reptiles that could burrow and subsist on subsurface vegetation (water storing roots) had the advantage of reduced metabolic demand. Moreover, evolutionarily efficient lung design coupled with advantageous gas perfusion-vascular resistance and acidity buffering tipped survival odds to favor dinosaur ancestors.

Diapsid Archosaurs out competed Synapsid Ancestor of Mammals Evidence in Alligator Breath.…

So when i go to the cameras on Icelands volcanoes i see
some pretty good glow over Helka.......
Is Helka now erupting?


Posted by: Passerby | March 25, 2010 4:37 PM
"Elevated CO2 and temperatures changed climate"

Empty claim!
Elevated CO2 promotes plant growth and makes plant more resistant to drought.

Submarine crews work long periods of time in environments containing + 3000 ppm with no physical effects.

Make your claim but leave CO2 out of it.
CO2 is in no way a climate driver.

By R. de Haan (not verified) on 25 Mar 2010 #permalink

@Boris, thanks for that update. I figured it was probably another lobe or something like that. In one of the videos, I saw people standing near the edge of that canyon and I sure wouldn't want to be there if a phreatomagmatic blast took place. Are those simular to litoral explosions?

@Mots, no, Hekla is not erupting or we would have heard about it. My guess as to what you are seeing is glow from the fissure.

@Mots. The Hekla webcam is trained south and what you see is (mostly) the glow of the Eyjafjöllajökull fissure, above and way beyond Hekla, reflected in its own smoke/steam. The reason it looks so bright is because the webcam uses a light-amplification device.

I asked this in another post but did not get a response. Is there a site that gives the So2 out put for this eruption ?
Or this may be a better question Is there typically a lot of SO2 in a Basalt eruption as compared to other types? Is it just a roll of the dice for the SO2 output or is there something to look for ?


By Dasnowskier (not verified) on 25 Mar 2010 #permalink

@Boris, on the other thread, you mentioned that volcanic tremor was due to degassing. I have wondered what caused volcanic tremor and I thought it was the magma pushing up in the conduit. I am beginning to see the difference between the quakes from rock breaks and tremor. I wish I knew how to read seizmic signals. Thanks for your contributions, again. I have been having so much fun on this blog.

@Dasnowskier, I don't know where you can get info about the SO2 levels. I would like to know also and the CO2 levels as well. I am sure someone will know soon what is being released.

@Dasnowskier, here is a link to a SO2 monitoring service, but I don´t know if the site is very good.

@R. de Haan, increased atmospheric CO2 levels can actually increase acidity in oceans. There are measurements that show that the pH levels in oceans is decresing. This could make life difficult for marine organism using shells and for corals. Here is a article you can read
You can find more info if you google on the subject. There are some youtube videos to but I haven´t checked them

By Mattias Larsson (not verified) on 25 Mar 2010 #permalink

Heh - everyone knows why the dinosaurs *really* went extinct. Anyone remember that cartoon by Gary Larsen?

By MadScientist (not verified) on 25 Mar 2010 #permalink

@Dasnowskier: Try to see if it is added at some stage; otherwise you would have to wait for a long time for someone to publish a paper. OMI is the best instrument currently in orbit to detect SO2; however it only works on the daylit side and the orbital geometry also affects coverage. The MODIS and AIRS instruments can see SO2 in the thermal infrared so they work on the night side - but due to the physics, SO2 estimates from the infrared data are typically ~30% lower than estimates from a UV instrument like OMI. (Orbital geometry is still an issue though.) Some eruptions don't throw SO2 high enough to be detected by some satellite instruments or simply don't produce enough SO2, in which case you won't get any SO2 estimates unless there were people doing measurements on the ground. However, current techniques employed for ground-based SO2 measurement do not produce very good estimates for the volume released or the rate of release. The amount of SO2 would depend on what's going into the melt - but you'd have to ask a volcanologist who does work on composition of the melt and the gases they release. If you have access to publications, there are numerous papers about minerals and gases involved in various volcanoes and types of eruptions.

By MadScientist (not verified) on 25 Mar 2010 #permalink

@R. de Haan: "Ten times the amount of CO2 as today does not cause a hot house."

Really? What evidence do you have for that claim? I'd also like to know how you know what temperatures dinosaurs are comfortable in.

By MadScientist (not verified) on 25 Mar 2010 #permalink

Erik Klemetti, Eruptions is an excellent volcanology blog. Imagine you are drawing many new readers. I enjoy the commenters you have attracted who also offer excellent ideas and some of the latest research with links. Yes, it is a feeling of joy to experience real science done according to the scientific method with necessary skepticism. Can't say that I find much of that feeling/experience with mainstream media or journals/mags like Science and Nature.

Glad to see Ron de Haan here, an "old" WUWT friend. Run-away heat with lots of CO2 seems much too simple anymore -- and likely wrong. Maybe scientists will finally take global warming and cooling seriously enough to much more closely examine the conditions that shift Earth in either direction.

By pyromancer76 (not verified) on 26 Mar 2010 #permalink

Have been reading a lot of earth sciences stuff the past year. Found this blog just prior to the eq spikes on Eyjaf, so it's been a really interesting ride. Thanks! Was taken aback at a recent post concerning the "plastic solid" state of the planet's interior - I'm perhaps one of duller tacks among your readers & moving into my dottage, but have always pictured the plates riding on that sea of molten magma. Can anyone take the time to educate me or throw me a site to read? My grandkids love watching "The Core" (argh), but apparently the scene where the magma is dripping down into the geode is quite impossible? Sorry if eyes are rolling - just trying to expand my grey matter before it becomes a useless soggy mass.

@ Boris: you think we're going to get to ask Doyle Rice some questions, too? Maybe he can even find us some information on Katla erupting coal.

@ Kathy: try to compare the Earth's mantle to a cube of ice. The cube looks very solid, but it's more liquid than many people would think. Take it out of its mold, put it in the freezer for three weeks (without the mold) and watch how it slowly deforms because of gravity. The materials in the mantle are even less liquid, but because of the enormous pressure down there it can slowly deform, so it kind of acts like a liquid.

Mantle plumes are a little bit more liquid (couple of percents) than most of the Earth's mantle and magma is a little bit more liquid than that. Then we have the difference between eruptible magma and magma that stays behind in magma chambers. Most of what can be found in magma chambers is more like a big mush that can't really go anywhere unless new melt enters the chamber and partially melts it to the point where it's liquid enough to erupt. The part of a magma chamber that is eruptible is usually not a lot more than 10%, which is a very broad estimate.

And then there's the difference between felsic ('explosive') and mafic ('effusive') volcanism. Eruptible magma in explosive volcanoes is actually more like liquid gas that's liquid because it's under extremely high pressure. When it erupts it immediately turns into ash, pumice and other gasses that form because of the interaction between the atmosphere and the gasses that were trapped in the magma. Volcanoes that produce red hot lava flows are usually more of the effusive kind. Basically that's the only place where you'll actually see that phenomenon.

The Earth's core is very solid. No movement there, not even like in the Earth's mantle.

By Gijs de Reijke (not verified) on 26 Mar 2010 #permalink

@Kathy B, I look at the mantle as layers of mush, much like oatmeal. If you cook oatmeal to the point that it just sits in the bowl, you can get an idea of what the lower area of the mantle is like. Add a bit of water and it begins to get a bit more fluid, but still like a glob in the bowl. Add more water to it and eventually it will flow out of the bowl rather than just a blob dropping out of it. The mantle, as Gijs has explained, has layers of solidity and only the very core of earth is really what you could say is "solid". It is thought to be made of iron.

The difference between mafic and felicic is the amount of silica it has in it, as I understand it. Take obsidian for instance. It is very glassy and has a lot of silica in it. Pumice, as in a kitchen pumice stone, and obsidian are basically the same thing. The difference is the pumice had a lot of gasses in it with a lot of bubbles. That is one reason it floats. I have a piece of obsidian that also has pumice on it and both have the same chemical composition.

Mafic lava flows are very fluid compared to the explosive stuff. It is much lower in silica content. Some of it can flow several miles/hour and cannot be outrun. It is amazing how fast it can flow and I think that usually produces pahoehoe flows. Aa flows are slower. (correct me, those of you who know more if I am wrong) I saw a film of an Etna eruption that took place in the '30s and this wall of slow moving aa type flow was about a block away from a lady's home and the police were trying to get her to leave. The lava was pretty high. It looked like a wall of about 20'! It was creeping along, but it wasn't so fast that people couldn't get away from it. It was an impressive film. The lava had a lot of blocky stuff in it and when it gets that aa type in there, the blocks slow it down.

Silica is the most common substance on earth. Its chemical formula is SiO2. A lot of other minerals get into it and that is what make studying magma, lava, rocks, and minerals interesting. You can tell what volcano some rocks come from just by the chemical composition.

Another bit if info that I am sure most people don't know is that a glass window pane is not solid. It is a fluid. When you look at an old original pane in an old house, you will see ripples in it. If you measure the thickness at the top and bottom of the pane, you will find the bottom is thicker because of the natural very slow flow of the glass. It is much like the icecube illustration Gijs gave you.

I hope this has helped you to better understand what is going on. Gijs did a great job of explaining it and I thought I would throw my two cents in.

Keep reading here and asking questions. You will learn a lot and there seems to be something different to learn every day because all of us, pros and amatures alike are learning because we just don't know what is happening sometimes. I don't even remember how I found this blog, but I am sure glad I did because there are some very great minds here with intriging ideas about what is going on.

>The Earth's core is very solid. No movement there, not even like in the Earth's mantle.

Really? Might want to do some fact checking, boyo.

"@R. de Haan: "Ten times the amount of CO2 as today does not cause a hot house."

Really? What evidence do you have for that claim? I'd also like to know how you know what temperatures dinosaurs are comfortable in."

Posted by: MadScientist | March 26, 2010 1:24 AM

Look at the graph in this article:…

How the hell do you expect me to now with what temperatures Dinosaurs are happy? It's an extinct species, don't you know that!

As for CO2, are you afraid the are not going to close down our economies by cutting the use of fossil fuels!

By R. de Haan (not verified) on 26 Mar 2010 #permalink

@ Passerbaby: I stand corrected ;-) . I meant the Earth's inner core... although I guess any material in any state can behave more or less as a liquid when it's put under high enough pressure.

By Gijs de Reijke (not verified) on 26 Mar 2010 #permalink


May I direct your attention to Dr Robert T. "Bob" Bakker, the renowned paleontologist who based on the prevalence of carnivore fossile remains in comparison to that of herbivore remains in a very particular location, the name of which currently escapes me, has supplied compelling evidence in addition to several items of equally compelling circumstantial evidence that dinosaurs were indeed warm-blooded. Therefore, it is safe to assume that dinosaurs would have "been happy" throughout a similar temperature range to that of other warm-blooded animals. Will this answer satisfy both gentlemen concerned? ;)

I am just wondering something here. Since Etna puts out 20,000 tons of CO2/24hr, and Kilauea puts out about 1600-2000 tons/24hr depending, and since there are a lot of other volcanoes steaming out CO2, what percentage do we think the volcanoes are producing vs. what industry is producing? Does anyone know the amount/day industry is producing vs the amount volcanoes are producing? Or has anyone taken the readings from industrial plants to see just what is being produced?

I think what industry is producing in miniscule compared with what the volcanoes are doing. And another thing that is happening is the methane releases in places in the ocean. So what is that doing to the atmosphere? It may not be much, but none the less, there are gasses being released and more than one type. I would think there is some effect on the atmosphere, but maybe some is only in the immediate vacinity.

I think the question is something on the order of just what is really contributing to the so-called global warming. I think it is more of the volcanic releases than what industry could be doing. Industry contributing to it? Yes, but not as much as some would have the rest of us think.

Any input on this arglebargle?

As someone who has degrees in geology (including a Ph D. from the same program during the time as our esteemed host was aalso a student there), I would be remiss if I didn't jump into the discussion about the mantle and core and clear up some misconceptions.

The mantle is solid and is made of silicate rocks we refer to as peridotites. It behaves ductilely at some depths and flows, but it is still a solid. An inexact but very useful analog is Silly Putty. It is not glass or semi-molten and like all rocks it is made of crystalline minerals. The flow occurs as the minerals undergo various types of deformations and "creeps" at elevated pressures and temperatures. This includes the proposed mantle plumes. It is a bit difficult to envision flowing solids moving through other solids because we don't readily witness it our everyday experiences.

Magma on the other hand is liquid formed by partial melting of rock, including mantle close to the surface under the right conditions. A mantle plume may rise from 1000s of km down, but would only begin to partially melt to form magma (by pressure release) close to the surface.

The core is an iron/nickel mix. The outer part of the core is liquid because that is the stable phase at those depths and temperatures, the inner part is solid because under the conditions deeper down the solid phase is the stable one.

@ EKoh, I have been wondering about this since the discussion began. How shallow is shallow? I realize in subduction zones volatiles rise from a considerable depth to play a role in magma genesis at much shallower levels. But what is happening here at Eyjafjallajökull? At what depth can we expect melt to be able to form? The crust thickens here from about 20 km at Eyjafjalla to 40 km or more at Vatna and there is obviously a lot of volcanism going on despite this thick crust.

Do you think it is possible for a layer of underplate melt to form at this depth or should we be thinking in terms of isolated pockets?

Secondly, what is driving the ascent of the magma? I take it mafic magma is more dense than the crust above it, so why is it rising up through 40 km of crust? Is it simply top pressure acting on a fluid?

Thirdly, do you have any explanation for the oscillations we saw in both the EQ swarms and the GPS readings? Is this a common occurence?

By bruce stout (not verified) on 26 Mar 2010 #permalink

@30 Bruce,
I'm bit rushed for any detailed answer at the moment, but didn't want to leave you hanging.
The depth were melting begins depends on how hot the rising mantle is. If it's 1200 C it could begin to melt when it 90 km, if 1100 C it would start around 30-40 km. There is model called polybaric melting where the mantle melts progressively as it rises, starting with few % down deep and increasing as it goes. Now if you have a lot of mantle upwelling from, then even melting 10% of it could make a nice size volume of bsaltic magma. If it is hotter mantle it would start to melt at deeper depths and by the time you hit the base of the crust a higher % of the mantle would have melted. Underplating would occur at the base of the crust, where the magma could stagnate for bit.
Partial mantle melt is basaltic. With basalt, unlike water, the liquid is lense dense than the solid so the magma is less dense than soldified basaltic crust (or grabbro since it cooled below ground)and will try to find it way to the surface, plus pressure increases with depth so there may be a bit of a squeeze from below. Boris may know off hand the thickness off the crust and estimates for melt volumes in Iceland.

I'm not a seismologist, so I can only speculate on oscillations and if they have any significance. It may be there is point at some depth in the crust where the bouancy force of small melt batches is not sufficient to open up fractures and accumulates until it has enough pressure to do so. Just arm-waving on my part.


Finally!!! Thanks a lot for your response. You wouldn't believe how long I puzzled over "dense" basalt rising through Si rich crust. I never came across that in my reading at all. It explains a lot.

I've got a ton of other questions for you btw.. :-)

By bruce stout (not verified) on 26 Mar 2010 #permalink

EKoh I asked this question in the other thread but didn't get an answer from an expert maybe you can help me.

I am asking about Mýrdalsjökull Caldera, I know the glacier on top of Katla is called Mýrdalsjökull, I am wondering about the Mýrdalsjökull Caldera:

"Monitoring of ice cauldrons

Mýrdalsjökull is the southernmost glacier in Iceland and is almost 600 km2. It covers the upper part of a large volcano. The mountain is about 30 km in diameter and the highest peaks reach 1500 m a.s.l. In the center of the ice cap is the Mýrdalsjökull caldera. It is oval in shape with the longest axis NW-SE and covers an area 110 km2. The highest points of the ice cap lie on the caldera rim and include Goðabunga, Háabunga, Austmannsbunga, Enta, Entukollar (see maps and pictures 1 and 2). Within the caldera the ice is hundreds of meters thick."

My question is whether Katla is just part of a larger caldera or is the Mýrdalsjökull caldera and Katla caldera one and the same. 30 km in diameter with an area 110 km2, that is pretty darn big and would seem to be much bigger than the Katla Caldera.

Posted by: Randall Nix | March 26, 2010 8:14 PM

"@R. de Haan, increased atmospheric CO2 levels can actually increase acidity in oceans. There are measurements that show that the pH levels in oceans is decresing. This could make life difficult for marine organism using shells and for corals. Here is a article you can read
You can find more info if you google on the subject. There are some youtube videos to but I haven´t checked them"

Posted by: Mattias Larsson | March 25, 2010 8:35 PM

Mattias larsson,

Just like the CO2 scare is a proven "lame duck, so is the ocean acidification scare.
Our marine life is doing very well!

Please visit some serious sites like Anthony Watts's or
Do a search for "Ocean Acidification" and find some serious scientific reports that debunk the scare entirely.

By R. de Haan (not verified) on 26 Mar 2010 #permalink

I visited Ubehebe crater just about one year ago. The road was in pretty bad shape. It was a moderately rainy winter, so it's possible there were some washouts as well. I don't think you can blame this closure on eco-hippie-liberals.

Neat crater, though. To my untrained eye, very similar to meteor crater in Arizona. Is there a rule of thumb for distinguishing between impact and explosive craters?

By YetAnotherKevin (not verified) on 26 Mar 2010 #permalink

@EKoh, I hope you didn't think I was saying the mantle was glass. I wasn't. I was using glass as an example of a solid that flows over time and I figured it might be a good analogy to use to describe the mantle. From what I was understanding was that the mantle was a "solid" mush type of stuff. I did not know it is really solid and I thank you for setting that straight. I did know that the crust doesn't float on a liquid mantle like lava crusts in a lava lake such as Erta Ale. I think a lot of people see it that way because it has been presented that way by those who don't understand the mantle/crust convergence.

One of the things I have a hard time getting my head around is having mantle upwelling if it is solid. And how does a mantle plume develop? Or is that something we don't know? I didn't see Silly Putty as a solid exactly, either. It seems funny to me that I can understand glass flowing, but I am having a hard time getting around the mantle being solid and yet it can flow. Arg! Maybe it will come to me if I just reread your posts a couple more times. You know, a blob of cooked oatmeal or cornmeal can be real solid if it has been put into the fridge. LOL

You said partially melted mantle is basaltic. I see from the current eruption the basaltic fountaining. What about rhyolitic lava? Does it flow at all like basalt only much slower?

I know. A lot of questions for a busy geologist. Are you a volcanologist, too? Sounds like it.

Thanks for your input. It is very helpful to get a handle on what is happening.

@YetanotherKevin, bad weather and washout is probably the culprit. However, one thing I have heard is that they (the department of Interior) will not replace or fix a road that gets washed out or eroded to the point of being impassible. It has happened up where I live and there are a lot of green gates all over the place where you used to be able to get to the river. There are three of the roads that they do keep open because they have to. They are fire escape routes if we need them. They actually paved one of them, but I doubt they will be paving the other two as the state has other things in mind and it probably would take an act of Congress (or an ammendment to a bill) to get anything like that done. One other road that goes to the river has not been graded in years and it is getting to the point of becoming impassible except for 4WD. I think when it goes, they will not repair it.

@R. de Haan: The problem with the link you provide is that there are so many things wrong with it; why do you even believe the claims? First of all, even the graphs are not sensibly labeled; there is no "Modtrans" but there is a radiative transfer model "Modtran". If you know what you're doing you can set up that model to give you some idea of the change in radiation trapped in the atmosphere due to CO2. Without details on how those figures were derived, I can't even trust those graphs. Modtran is not like a computer game where anyone who can push buttons can operate it, and doing the types of radiative transfer calculations needed to substantiate the claims being made, you're looking for someone with an appropriate PhD to run that model because the information we're looking at is not a typical output from Modtran - you have to run an awful lot more calculations than the basic model provides. Now on top of that, the figures posted claim to be a "forcing" - not a temperature change. What corresponding temperature change might be expected is conveniently ignored. The plot on "heating effect of CO2 per 20ppm increment" is irrelevant and misleading, not to mention once again, where do their numbers come from? 10 times the CO2 in our atmosphere will make a much warmer planet, despite the ridiculous claims of that website. If those people wanted to make an honest argument, they'd state a published claimed temperature increase for the x10 CO2 and show their own detailed calculations of why that is wrong. That website does not give any relevant information, it only pretends to be science.

By MadScientist (not verified) on 27 Mar 2010 #permalink

There is nothing wrong with the data in the link besides the notion that you want the data to be wrong because you are a warmist, an alarmist and a "Believer". Sorry to say this but this is the truth

The role of CO2 in the IPCC models is overstated by a factor 6 to 7.

That's why the models and the real world observations don't match.

Do you get this!

By R. de Haan (not verified) on 27 Mar 2010 #permalink Haan and MadScientist, how about presenting more articles as evidence of the theories of CO2 effect on the atmosphere and possible warming and maybe that could cool the discussion a bit.

I would like to see more than just one article on either side of the issue because just one article sometimes isn't enough to "prove" a theory. How about the ability to reproduce a study? How many studies have actually been done to get an idea of CO2 effects? What do the ice cores show? What has the plant life shown since the Holocene?

Anyway, I think what can really help here is more info presented on this whole issue. I do believe there is possibly some warming going on because we have been coming out of what they called the Little Ice Age. Glaciers are retreating. The snow in the Sierras used to stay all summer long in the '50s and now it doesn't. I am not going to say with the alarmists it is because of human indutrial output. I think most of the CO2 comes from seepage and volcanoes. I am sure there are other sources. Even our breathing produces it. (Now I am not saying our exhalations are a cause of warming. LOL

So what else can you two present on this issue?

I was thinking more of... not sure how to say it. Features of the crater itself, I guess. Like maybe impact craters have a characteristic shape that differs from the typical volcanic crater? Probably the best rule of thumb for me is, "It's volcanic." because I'm statistically likely to be right. :-)

Back-of-the-napkin calculation for total human CO2 emissions: Get an estimate for the annual production of coal and oil, which shouldn't be too hard. Assume it's 100% carbon and that 100% of it is burned (*). Add the weight of two oxygen atoms for each carbon atom. (multiply by 3.7) (**)

(*) Obviously this is an overestimate, but we're not counting natural gas, so it should be close enough. Might be within the error bars for the annual production, anyway. Go ahead and re-run the calculations assuming 90% is carbon and 90% is burned.

(**) The third link below provides much better conversion factors, which I've used (hopefully correctly) in my calculations.

Aw, heck. I'm curious now.


In 2006, 6,807 million short tons of coal annually. .907 metric tons per short ton.

C02 from coal: 6,807 * .907 * .982 * .746 = 4522 million tons per year, or 12.4 million tons per day, or 620 Mt. Etnas.

In 2008, 85.5 million barrels of oil per day. This is approximately 12 million metric tons.

CO2 from oil: 12 * .98 * .85 = 10 million tons per day, or about 500 Mt. Etnas.

Hope this thread isn't completely dead.

By YetAnotherKevin (not verified) on 27 Mar 2010 #permalink

@36 Diane, I hope you didn't think I was singling out tyour comment. I was just trying to clear things up for everyone. You are right that many people think that crust floats on a liquid mantle. I did so myself before studying geology, I think it is a common misconception fueled by some poorly doen popular science explanations.
Rhyolite is much more viscous than basalt and really flow very well at all. Think heavy cream vs. wall putty. Basalt also does not degass as easily as basalt and often holds onto any gas until it breaches the surface, releasing it all at once and explosively. This results in ash instead of lava flows. If rhyolitic magma does erupt without explosively fragmenting it does not flow very far and makes a dome of solidified rhyolite right at the vent. Rhyolitic lava would behave very similarly to the dacite that erupted at St. Helens from 2004-2008. Sometimes it will quench to glass and make an obsidian dome. Much rhyolitic magma never makes it to the surface and crystallizes into plutons of granite.

Technically speaking I am an igneous petrologist, meaning I specialize in the origins and development of magma and igneous rocks. The field obviously overlaps into volcanology. In fact, I attended grad school with Erik and also Anne Jefferson, who blogs over at Highly Allocthanous.

@EKoh #42, I'm afraid I did think you were referring to me. Sometimes I get the wrong idea and I appologize for that. Thank you so much for your explainations. I did not know that ryolitic magmas will become granites. I didn't know exactly how granite formed, but I knew it was igneous. I have been a rockhound since I was about 3 and I have been interested in volcanoes since I was about 9, and I wish someone had steered me into geology about 30 years ago! Well, I can study it now and I am so glad, (maybe I have said it too much lol) I found this blog. I feel priviliged to be able to communicate with geologists and volcanologists and learn from them.

Thank you again.

Dang! Looks like my comment got eaten by the system.

@Diane: Regarding industrial C02 output, there are sources (DOE among others) that provide the annual production of coal and oil, and others that provide the conversion to C02. I'm not going to do it again, but it didn't take very long, and what I came up with was C02 from burning coal = 630 x Mt Etna and C02 from burning oil = 500 x Mt Etna. Plus or minus 11 percent or so. I didn't check natural gas.

By YetAnotherKevin (not verified) on 28 Mar 2010 #permalink

Thank you, YetAnotherKevin. I appreciate the work you did to find that for me. Hmmm. Looks like industry does put out a lot more CO2 than I thought. Something to think about.

@R de Haan: That link you provided is as scientific as astrologist claims that volcanoes erupt due to planetary alignments. The web site does not pass even the most superficial examination. But since this blog is about volcanoes, I'll say no more of that.

By MadScientist (not verified) on 29 Mar 2010 #permalink

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