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dgavin
2009-Jun-12, 01:51 AM
New Scientist published an article today about the potential of super volcano beeneth Mt. St. Helens.

Full Article (http://www.newscientist.com/article/mg20227124.700-supervolcano-may-be-brewing-beneath-mount-st-helens.html)


Peering under the volcano has revealed what may be an extraordinarily large zone of semi-molten rock, which would be capable of feeding a giant eruption.
Magma can be detected with a technique called magnetotellurics, which builds up a picture of what lies underground by measuring fluctuations in electric and magnetic fields at the surface. The fields fluctuate in response to electric currents travelling below the surface, induced by lightning storms and other phenomena. The currents are stronger when magma is present, since it is a better conductor than solid rock.

...



A magneto what?

I have to go on the record here as stating this this article is complete hog-wash.

First they don't account for water properly.

Secondly they don't acount for the fact the the water in volcanic regions is acidic, and with the metals present in these regions can cause electro chemical reactions.

Third, the Magma pocket at 15km to the base of the plates has been known about for years.

A similar idea was originaly proposed in the 50's before seismic tomology was readily used, back then there was a standing theory that there was a broken off peice of jaun-de-fuca plate that traped itself in the melt zone, and was slowly pulverized and melted over millions of years, the peices of which, still solid in the melt zone tended to act a bit like giant ball bearings.

Since that time, seismic tomology has already show that while there are deeper larger pocktes of magma, (roughly 3 under oregon (one hot spot related) and three under washington) they were at a debth (15km or deeper) that was not condusive to eruptive behavior.

The magma instead seeps up to smaller pockets at 2-9km debth, and it's these secondary smaller pokets that feed the eruptions.

Fourth, there has not been any documented uplift of a region from magma pockets deeper then 12km. Of the three Supervolcanic area in the west, Yellowstones huge pocket of Magma is 2km to 5km deep. Newberry's is around 4-8 km deep, Long Valley's caldera's is about 3-7km deep.

Those are all a far sight shallower then 15km-45km debth of the subduction melt regions.

Don't buy into this hype about this article.

Magnetotellurics is an untested science when applied to volcanoes, and they didn't even bother to compare thier results to siesmic tomological sources that are readily available now.

Gillianren
2009-Jun-12, 02:02 AM
Not an expert, no geology classes in ten years, etc.

If Mount St. Helens were a supervolcano, wouldn't there be an awful lot of hotsprings and geysers and things between it and, oh, Rainier? Wouldn't that mean I wouldn't have to go all the way to the Olympic Peninsula--and the northwest corner, at that!--to find natural hotsprings?

dgavin
2009-Jun-12, 02:10 AM
Not an expert, no geology classes in ten years, etc.

If Mount St. Helens were a supervolcano, wouldn't there be an awful lot of hotsprings and geysers and things between it and, oh, Rainier? Wouldn't that mean I wouldn't have to go all the way to the Olympic Peninsula--and the northwest corner, at that!--to find natural hotsprings?

Basicaly yes, you are correct, and that is a fifth item that is in direct eveidence against this idea of some sort of super volcano in the region.

Yellowstone is the most abundant geothermal region on the planet because of the extreamly shallow debth of it's magma. Long Valley calldera is much less geothermally active because of the deeper debth, Newberry Caldera has one two hot springs I know of, and it's magma pocket is deeper still.

novaderrik
2009-Jun-12, 04:48 AM
if you go deep enough, there is a LOT of magma below any point on the surface of the earth- so the entire planet is a potential super volcano.

aurora
2009-Jun-12, 04:59 AM
All of the volcanoes in the Cascade chain, from Northern California all the way to British Columbia, are very similar.

Well, maybe except for Newberry.

But they all have similar life histories, similar chemistry.

If someone thought Mt St Helens should be classed in the mega category with (in the US) Long Valley, Yellowstone, and the one in New Mexico the name of which I cannot at the moment recall, then the case would have to be made as to what made St Helens different from the other Cascade volcanoes.

dgavin
2009-Jun-13, 12:30 AM
Valles Caldera is the new Mexico one. From my understanding the New Mexico volcano's are Continental Rift volcano's, putting them into a class of thier own.

However it is very likely the the rifting that started in that region was spawned by the hotspot plume head that caused the CRB (Coumbia River Basin) Flood Bassalts and the formation of the Great Eliptical Basin that encopases Oregon, Washington, Idaho, and parts of Nevada, New Mexico, California, Montana and Wyoming. And later on split off to become the Yellowstone, Newberry, Long Valley caldera's.

So it's possible that part of it's magma is also fed by both rift vulcanism and hot spot vulcanism. Much like Newberry is a Hotspot/Subduction mix.

*Edit to add*

And yes, it's still an active region , although dormant fro the last 3000 years. Natives have some intresting accouts of historical eruptions in that region.

flynjack1
2009-Jun-13, 03:34 PM
Valles Caldera is presently a beautiful area with great fishing and even better elk hunting(very hard to draw). The evidence of its last eruption is literally all over the place in NM. Tuft rock provides interesting homes for the early Pueblo peoples. Mount Taylor (near Grants NM). Has a similar sized caldera to Mt. St. Helens. The Valles Caldera is much larger than Mt. Taylor's.

Dgavin: For what its worth I read the article too and thought it a bunch of hooey. by the way I thought that most super volcano's were not subduction zone volcano's or am I mistaken on this? Tambora clearly was a Ring of Fire volcano. Opinions from the more educated welcome.

Ara Pacis
2009-Jun-13, 04:06 PM
by the way I thought that most super volcano's were not subduction zone volcano's or am I mistaken on this? Tambora clearly was a Ring of Fire volcano. Opinions from the more educated welcome.

Tambora is not a supervolcano. You're probably thinking of Toba, the one that killed most of humanity around 70,000 years ago. Tambora only killed ~70,000 local inhabitants.

dgavin
2009-Jun-13, 09:10 PM
Flynjack1: Supervolcanos are usualy associated with hotspot's or Rifts. Newberry Caldera might be an exception, but it's a wierd mix of both hotspot and subduction magma's.

beskeptical
2009-Jun-14, 02:02 AM
Interesting study conclusion.

JonClarke
2009-Jun-14, 07:26 AM
New Scientist published an article today about the potential of super volcano beeneth Mt. St. Helens.

Full Article (http://www.newscientist.com/article/mg20227124.700-supervolcano-may-be-brewing-beneath-mount-st-helens.html)

[QUOTE]A magneto what?

Magnetotellurics, the study of deep Earth electrical behaviour. Wikipedia is your friend - go to http://en.wikipedia.org/wiki/Magnetotellurics


I have to go on the record here as stating this this article is complete hog-wash.

You might like to reconsider.


First they don't account for water properly.

How so?


Secondly they don't acount for the fact the the water in volcanic regions is acidic, and with the metals present in these regions can cause electro chemical reactions.

This is only sometimes true, and generally only in the upper parts of high sulphidation hydrothermal systems where H2S gets oxidised to H2SO4.

Even if the water is acidic, how does this invalidate the hypothesis?


Third, the Magma pocket at 15km to the base of the plates has been known about for years.

Agaion, so what? What is new is the extensive connection between the magma pocket and the volcano.


A similar idea was originaly proposed in the 50's before seismic tomology was readily used, back then there was a standing theory that there was a broken off peice of jaun-de-fuca plate that traped itself in the melt zone, and was slowly pulverized and melted over millions of years, the peices of which, still solid in the melt zone tended to act a bit like giant ball bearings.

Plate tectonics was not known in the 1950's. Even continental drift was ridiculed in the US.


Since that time, seismic tomology has already show that while there are deeper larger pocktes of magma, (roughly 3 under oregon (one hot spot related) and three under washington) they were at a debth (15km or deeper) that was not condusive to eruptive behavior.

The magma instead seeps up to smaller pockets at 2-9km debth, and it's these secondary smaller pokets that feed the eruptions.

How does this invalidate new conclusions from additional data?


Fourth, there has not been any documented uplift of a region from magma pockets deeper then 12km. Of the three Supervolcanic area in the west, Yellowstones huge pocket of Magma is 2km to 5km deep. Newberry's is around 4-8 km deep, Long Valley's caldera's is about 3-7km deep.

Hence the emphasis on the word "nasacent" in the article. This is not a supervolcano, it may eventually become one.


Those are all a far sight shallower then 15km-45km debth of the subduction melt regions.

Subduction zone melts are sourced from a lot deeper than this, typically 80 km or more. Any magma body less than this is ponding within the crust or at its base.


Don't buy into this hype about this article.

So far the article has stood up very well.


Magnetotellurics is an untested science when applied to volcanoes, and they didn't even bother to compare thier results to siesmic tomological sources that are readily available now.

Since you don't seem to know what magnetotellurics is ("A magneto what?") how do you know it is untested?

Since there are almost 2000 links to magnetoelluric studies of volcanoes all over the world in Google Scholar, it is hardly untested.

No cross reference to seismic tomography? It's a 139 abstract for goodness sake, not a full blown paper.

Did you even bother to read the link to the source abstract?

Jon

cran
2009-Jun-14, 04:19 PM
New Scientist published an article today about the potential of super volcano beeneth Mt. St. Helens.

...

I have to go on the record here as stating this this article is complete hog-wash...



I think the issue here is that the article is in a public consumption magazine; the sensationalist "supervolcano" slant appears to be supplied by the staff writer, whose job it is to attract attention -

10 June 2009 by David Shiga (http://www.newscientist.com/search?rbauthors=David+Shiga)
IS A supervolcano brewing beneath Mount St Helens?The article itself is saying that there's enough magma for a "giant eruption" (whatever that means in quantitative terms - was Mt St Helens a "giant eruption"? Krakatoa? Pele? Vesuvius?), but the focus of the study is that the magma source seems to be connected to more than one volcano, not that all the magma is expected to rush out in one place at one time ...

The conference presentation (which is what the article was supposed to be about, but which was somehow lost in the writing/editing) was bringing together a number of studies of the magmatic interconnections within the volcanic chain ...

Other than that, Jon has covered the pertinent points ...

dgavin
2009-Jun-14, 10:26 PM
Cran:


I think the issue here is that the article is in a public consumption magazine; the sensationalist "super-volcano" slant appears to be supplied by the staff writer, whose job it is to attract attention

Yes that is exactly my issue. Instead of producing an article about some odd readings, that I might add other magnetotelluric studies have noted in the past and interpreted them as sedimentary layers (http://adsabs.harvard.edu/abs/1984JGR....89.4447S)... They chose to put a fear mongering super volcano slant onto the research.

As soon as someone does this, justifiable or not, it puts the article and the research it's based on into the category of Hype and possibly Tripe.

So yes my issue is with the article mostly, but that doesn't absolve the researches from choosing a magazine that has a less then good reputation.


JonClarke:


Plate tectonics was not known in the 1950's. Even continental drift was ridiculed in the US.


That is a misleading statement, as early as 1920's the plate junction theories in seafloors was proposed, followed by the 1928 mantle convection currents theories. In 1956 they had the first evidence that the continental drift and expanding earth models were not correct, and proponents of both those theories beginning starting a collaborative work on what would become Plate Tectonics in the 1960's.

So 1950's is accurate, unless you want to discount the development time Plate Tectonics took.


Subduction zone melts are sourced from a lot deeper than this, typically 80 km or more. Any magma body less than this is ponding within the crust or at its base.


The cascade and California region has a Continental plate thickness that varies from 15km thick around San Andreas fault, to 30-45km thickness elsewhere. So the subduction melt zone of the juan-de-fuca are occurring around 45km depth, generally speaking. Likely shallower as indicated by the spacing of volcano's amounts other things.


You might like to reconsider.

No I don't think so. As soon as someone promotes a idea via fear mongering, I'm going to consider both the article, and the idea, hog wash.

While magnetotellurics seems to be a usefully tool for some things, mining, location of substances with known electrically properties, etc...

The only electrical property study of magma I've heard about was from 'Simulated' magma using man-melted basalt rocks. While that might give clues, it definitely does not account for the amount of water in the magma in these regions. So there is really no good baseline for telluric study of subduction water rich magma.

So at best the baseline they could be using is more tuned to hotspot volcanism and magma's.


How so?

....

This is only sometimes true, and generally only in the upper parts of high sulphidation hydrothermal systems where H2S gets oxidized to H2SO4.

Even if the water is acidic, how does this invalidate the hypothesis?


Well even another magnetotelluric went into that in the article, and i think I covered it a bit better in my above statement.

Acidic water and metals can chance the electrical properties of things. Batteries are based on that idea, while I'm not suggesting there is a giant battery underground, their research also doesn't seem to account for things of this nature.


Again, so what? What is new is the extensive connection between the magma pocket and the volcano.


The connection of volcano's secondary feeder pools to larger primary pools has been know about for a long time. It's even been discussed on this board before. There are quite a few images from seismic tomology available to the public that show these. I can't say the same about magnetotelluric images being readily available to public, even from USGS sources.


How does this invalidate new conclusions from additional data?



So far the article has stood up very well.


Since there are almost 2000 links to magnetotelluric studies of volcanoes all over the world in Google Scholar, it is hardly untested.


There are over 16,500 articles about seismic tomology in comparison. Which has produced imaging and profiles of magma pockets readily available. The same can't be said for magnetotelluric studies.

While it might be a useful tools once the electrical properties of subduction magma is known, until then at best it's a rough guess.

Again their conclusions are invalidated by their method of choice is publishing it as a "Super Volcano" fear mongering tactic, in a magazine that is often associated with pseudoscience and bad science. The researchers should of given better thought to what magazine they wanted representing them.

I will give the team of research kudos for at-least having it peer reviewed, although I can't locate results of the reviews it does look like it was done. However again I totally fault them for their choice and method of public outreach for reasons mentioned before. If they wanted to be taken seriously, then they should have chosen a serious magazine.

And again, there is no know historical evidence of a super volcano occurring from magma pools deeper then 12km. While I'm not arguing the link of the primary larger pools to the smaller secondary feeder pools, I am arguing their choice of relating it to a super volcano. That part of it is pure hype.

cran
2009-Jun-15, 05:42 AM
Cran:



Yes that is exactly my issue. Instead of producing an article about some odd readings, that I might add other magnetotelluric studies have noted in the past and interpreted them as sedimentary layers (http://adsabs.harvard.edu/abs/1984JGR....89.4447S)... They chose to put a fear mongering super volcano slant onto the research.

As soon as someone does this, justifiable or not, it puts the article and the research it's based on into the category of Hype and possibly Tripe.

So yes my issue is with the article mostly, but that doesn't absolve the researches from choosing a magazine that has a less then good reputation...



How do you know the researchers chose the magazine?

It's been my experience* (especially in conferences) that the media select the targets, and determines the slant, often without consultation, and not uncommonly leading to complaints by the targets after the fact -

researchers, etc, generally submit actual papers to the most credible journals they can access, conference and presentation papers to the conference organisers, and a stock media release which can be accessed by everyone else -

more often than most would like to admit, public consumption articles are sourced completely from the media release - including direct quotes - and then padded out (or thinned down) to fill the column inches and where possible to reflect editorial policy, which is commonly to include an eye-catching (or sensational) opening statement ...

*my experience includes that of being a general and industrial journalist for three decades ... and I've had to face the unpleasant situation of apologising to a mining company exec for a direct quote that was altered by a senior editor (without consultation, and which adversely altered the meaning of the original statement) after I'd submitted the story ...

there is no right of prior refusal by the target against the media - the only recourse before print is a court order ... of course, the target would have to know beforehand that a disagreeable article is being prepared, and would then have to convince a judge that printing the article would violate some part of the law or government act of legislation ...

So, I wouldn't be too quick to blame the researchers for a media act ...

beskeptical
2009-Jun-15, 06:28 AM
...
So, I wouldn't be too quick to blame the researchers for a media act ...I agree mostly. New Scientist is definitely not a science journal.

OTOH, there are those who question the interpretation of the findings saying an aquifer would also account for the data.

I'm not one who has the expertise to judge either interpretation, however, historically the closest thing to a supervolcano eruption in the geological record of the Cascades was Mt Mazama which exploded leaving Crater Lake in OR. I don't think that supports these researcher's findings.

dgavin
2009-Jun-15, 06:51 AM
Cran,

Your point is well taken.

However I don't think the researchers were entierly blameless in this case. I did look over various sources and the researches discussed posibilities of "Giant Eruptions" but haven't found the context of what they were refering too.

So it's possible that the media modified that into Supervolcano on thier own.

But somethign about the research doesn't right quite right either (as pointed out before). However without access to the abstract or the transcripts from the conference, it will be hard to debate further.

dgavin
2009-Jun-15, 07:00 AM
I agree mostly. New Scientist is definitely not a science journal.

OTOH, there are those who question the interpretation of the findings saying an aquifer would also account for the data.

I'm not one who has the expertise to judge either interpretation, however, historically the closest thing to a supervolcano eruption in the geological record of the Cascades was Mt Mazama which exploded leaving Crater Lake in OR. I don't think that supports these researcher's findings.

Intrestingly enough, some native american legends of that eruption survived. And somewhat accurate also, considering it was passed by word of mouth for 7000 years.

cran
2009-Jun-15, 07:15 AM
Cran,

Your point is well taken.

However I don't think the researchers were entierly blameless in this case. I did look over various sources and the researches discussed posibilities of "Giant Eruptions" but haven't found the context of what they were refering too.
yes, I noted the lack of context also ...


So it's possible that the media modified that into Supervolcano on thier own.

But somethign about the research doesn't right quite right either (as pointed out before). However without access to the abstract or the transcripts from the conference, it will be hard to debate further.

Agreed. Part of the difficulty re public consumption (or pablum) media is that it tends to preempt any real peer review of a serious submission -
so, even ignoring that the original announcement is misinterpreted (or misrepresented), it could (as you've indicated) simply turn out that the submitted conclusions were in error ... it happens ...

then, of course, the magazine has ammunition to hang the researchers out to dry - and another sensational headline ...

JonClarke
2009-Jun-15, 09:42 AM
JonClarke:

That is a misleading statement, as early as 1920's the plate junction theories in seafloors was proposed, followed by the 1928 mantle convection currents theories. In 1956 they had the first evidence that the continental drift and expanding earth models were not correct, and proponents of both those theories beginning starting a collaborative work on what would become Plate Tectonics in the 1960's.

So 1950's is accurate, unless you want to discount the development time Plate Tectonics took.

No, it is not misleading. While observations in support of it go back to the 16th century, plate tectonics as a theory did not exist until the term was coined by Morgan in 1967.


The cascade and California region has a Continental plate thickness that varies from 15km thick around San Andreas fault, to 30-45km thickness elsewhere. So the subduction melt zone of the juan-de-fuca are occurring around 45km depth, generally speaking. Likely shallower as indicated by the spacing of volcano's amounts other things.


The base of the continental crust is not where subduction zone melts are generated. They are generated deeper, in the mantle in the subducted slab, 36-66 km, according to Tanton and others. While shallow by global standards (hence my earlier 80 km figure), but still deeper than your 15-45 km.


No I don't think so. As soon as someone promotes a idea via fear mongering, I'm going to consider both the article, and the idea, hog wash.

You choice, but it is a gross over-reaction on two levels. First of all the NS article is not fear mongering. Secondly, even if it were, this does not invalidate the orignal study.


While magnetotellurics seems to be a usefully tool for some things, mining, location of substances with known electrically properties, etc...

The only electrical property study of magma I've heard about was from 'Simulated' magma using man-melted basalt rocks. While that might give clues, it definitely does not account for the amount of water in the magma in these regions. So there is really no good baseline for telluric study of subduction water rich magma.

You need to read more widely. Magnetotellurics have been extensively used to study water rich volcanoes over subduction zones - Stromboli, Fuji, Marapti, Piranacota, Lascar - and many others. It is a standard technique. It is also used to study hydrothermal systems and map their distributuion within volcanic edifices. Google is your friend.


So at best the baseline they could be using is more tuned to hotspot volcanism and magma's.

Nope, it has been widely used for island arc volcanoes as well.



Well even another magnetotelluric went into that in the article, and i think I covered it a bit better in my above statement.

Do you know how journalists work? They always want both sides, and they will hunt round until they find a contrary opinion. It does not mean that the opinion is well founded.


Acidic water and metals can chance the electrical properties of things. Batteries are based on that idea, while I'm not suggesting there is a giant battery underground, their research also doesn't seem to account for things of this nature.

And you base this on reading a story derived from a 139 word abstract? How do you know they do not?


The connection of volcano's secondary feeder pools to larger primary pools has been know about for a long time. It's even been discussed on this board before. There are quite a few images from seismic tomology available to the public that show these. I can't say the same about magnetotelluric images being readily available to public, even from USGS sources.

The USGS is not the source of all knowledge (although they would like to think so). An magnetotelluric studies of volcanic and hydrothermal systems has been round fopr quite sometime, even if you haven't seen the results.



There are over 16,500 articles about seismic tomology in comparison. Which has produced imaging and profiles of magma pockets readily available. The same can't be said for magnetotelluric studies.

There are roughly twice as many seismic tomography studies on volcanoces. So what? It is an older technique. This does not invalidate the thousands of studies with a newer method. It's like like rejecting GPR because it isn't as old as seismic reflection.


While it might be a useful tools once the electrical properties of subduction magma is known, until then at best it's a rough guess.

The electrical properties of magmas are known quite well.


Again their conclusions are invalidated by their method of choice is publishing it as a "Super Volcano" fear mongering tactic, in a magazine that is often associated with pseudoscience and bad science. The researchers should of given better thought to what magazine they wanted representing them.

The authors did not chose to publish it as a ""Super Volcano" fear mondering tactic" - the abstract does not contain the word. It was published as a conference abstract, NS decided to run the story and suggest a link with super volcanoes. And they could be right, some super volcanoes are in island arcs, and why a normal chain of ilsand arcs becomes a super volcano is not understood.


I will give the team of research kudos for at-least having it peer reviewed, although I can't locate results of the reviews it does look like it was done.

Conference abstracts are not peer reviewed. When articles are peer reviewed, reviwers comments are confidential.


However again I totally fault them for their choice and method of public outreach for reasons mentioned before. If they wanted to be taken seriously, then they should have chosen a serious magazine.

NS is one of the most widely read popular science magazines in the world. If they approached me for a story I would be very pleased to give them one. But a story in a popular science magazine does not be taken as scientific publication.


And again, there is no know historical evidence of a super volcano occurring from magma pools deeper then 12km. While I'm not arguing the link of the primary larger pools to the smaller secondary feeder pools, I am arguing their choice of relating it to a super volcano. That part of it is pure hype.

The Toba volcano magma chamber is 15-30 km deep from the distribution of P and S wave velocity anomalies and from seismic tomography.

Once again, the super volcano link is in NS, not the abstract. But NS does not say that the Cascades are a supervolcano, they say it may be a nascent one. That is a very different kettle of fish and it might even be right. It may be quite possible that in five million years the Cascades willo evolve into a super volcano. How is this hype and fear mongering?

Jon

dgavin
2009-Jun-15, 02:26 PM
No, it is not misleading. While observations in support of it go back to the 16th century, plate tectonics as a theory did not exist until the term was coined by Morgan in 1967.


Semantics, Arthur Holmes in 1929 published the mantle convection therory, which is the basis of Plate Tectonics. Harry Hess in 1962 and R.Dietz in 1961 published additionaly work based on evidence that Holmes mantle convetion was correct, and those publications are what became Plate Tectonics.

And they did not publish write it over night, the work began in 1956.


The base of the continental crust is not where subduction zone melts are generated. They are generated deeper, in the mantle in the subducted slab, 36-66 km, according to Tanton and others. While shallow by global standards (hence my earlier 80 km figure), but still deeper than your 15-45 km.


The melt is generated at the junction of the subduction zone by the friction of the plates themselves, which superheate the water in the subudted plate this has the effect of lowering the metling point of the rock in the plates. So it's not generated in the mantle at all. It's why subduction magma is vastly different from hotspot of rift magma.


You choice, but it is a gross over-reaction on two levels. First of all the NS article is not fear mongering. Secondly, even if it were, this does not invalidate the orignal study.


Possibly not, but again without a context of what they ment by "Giant Eruputions" in thier presentation, it's hard to debate further.


There are roughly twice as many seismic tomography studies on volcanoces. So what? It is an older technique. This does not invalidate the thousands of studies with a newer method. It's like like rejecting GPR because it isn't as old as seismic reflection.

Perhaps, but the only evidence I found was for simulated man-melted bassalt experiments, which is not accurate for subduction magma that has a high concentration of water that is mostly lost by the time it reaches the surface.

As to the rest I did agree with cran that perhaps the media did latch onto Giant Eruptions and modified that to Super Volcano to attract readers.

Gillianren
2009-Jun-15, 04:34 PM
You know, speaking as someone who lives within range of a "Giant Eruption" or possibly theoretically over a "supervolcano," I find either propsect a little disconcerting.

jj_0001
2009-Jun-15, 07:38 PM
Well, I tend with DGavin on the evaluation, at least until more evidence emerges, however I must say that my own experiences with the media in my own field suggest that the authors may be blameless.

No more will I say, because I don't want to say it politely.

dgavin
2009-Jun-15, 07:42 PM
Gillianren,

Thats one of the reason's I take exception with that article, and to a lesser degree (until it's publicly available) the research itself.

There is no historical evidence of catastophic super volcanic eruptions in the main cascade volcano's, with the notable exception of Newberry which is hot spot fed in part.

As long as the cascade stratavolcanoes remain active, the likely hood of a supervolcano type eruption is remote. Very very remote. It takes hundreds of thousands of years, sometimes close to a million years, for presures in large magma pools to reach a point thats condusive to super eruptions.

As long as the pressure has outlets in the form of the average 1 eruption every 75years (or so) in the cascades, the conditions that form super-eruptions won't happen.

Now if every volcano in the cascades had been dormant for a few hundred throusand years, then there might be something to be concerened about. Right now there really isn't.

JonClarke
2009-Jun-17, 07:41 AM
Semantics, Arthur Holmes in 1929 published the mantle convection therory, which is the basis of Plate Tectonics. Harry Hess in 1962 and R.Dietz in 1961 published additionaly work based on evidence that Holmes mantle convetion was correct, and those publications are what became Plate Tectonics.

Not sematics at all. It is a historicval fact that plate tectonics was both a term and a coherent theory did not exist until 1967. Read any standard text book of the history of plate tectonics. 1967 was the critical year.

Aspects of it were proposed before then, by Holmes (whom I have read, have you?) Wegner, Carey, du Toit, King, and others. Hess and and other marine scientists collected marine bathymetry, magnetism, sediment core and other date in the 50's that led to the proposal of seafloor spreading in the early 60's. But 1967 was the critical year, with several key papers independently proposing the idea.


And they did not publish write it over night, the work began in 1956.

Mid ocean rifts were discovered in 1956. This does not mean that work on the theory started then. If you follow the paper trail it is very clear that plate tectonics as a concept began in 1967. The preivious year the idea of sea floor spreading was well developed and many of the key observations were in place, but the conceptual break through had not happened.


The melt is generated at the junction of the subduction zone by the friction of the plates themselves, which superheate the water in the subudted plate this has the effect of lowering the metling point of the rock in the plates. So it's not generated in the mantle at all. It's why subduction magma is vastly different from hotspot of rift magma.

You are correct in saying that the water in the subducted slab acts as a flux and lowers the melting point. However you are incorrect regarding frictiona heating. this plays at best a very minor role in the generation of island arc melts. When a slab is subducted it is no longer part of the crust, but contained within the mantle. The water being given off by the subducted slab also acts as a flux in the mantle causing further melting. Hence the presence of igenous rocks of diverse compositions in island arcs.


Perhaps, but the only evidence I found was for simulated man-melted bassalt experiments, which is not accurate for subduction magma that has a high concentration of water that is mostly lost by the time it reaches the surface.

There has been a vast amount of experimental petrology on a very wide range of real and theoretical magma compositions. I and S type granites, andesites, hydrous and anhydrous basalts, komatiites, have all been extensively studied.


As to the rest I did agree with cran that perhaps the media did latch onto Giant Eruptions and modified that to Super Volcano to attract readers.

Possibly so, and it is not unreasonable, whether it was justified I don't know. It depends how much additional information was supplied by interview with the author.

Jon

JonClarke
2009-Jun-17, 07:45 AM
You know, speaking as someone who lives within range of a "Giant Eruption" or possibly theoretically over a "supervolcano," I find either propsect a little disconcerting.

Well you can always take refuge in the attitude of most people who live in such environments: "It isn't likely to happen in my lifetime!" :)

JonClarke
2009-Jun-17, 08:10 AM
There is no historical evidence of catastophic super volcanic eruptions in the main cascade volcano's, with the notable exception of Newberry which is hot spot fed in part.

Hence the story's statement "nascent". This is something that might develop in the future. There was no sign of a super volcano at in Sumartra half a million years ago, just ordinary island arc volcanoes. The the Toba volcano started erupting.


As long as the cascade stratavolcanoes remain active, the likely hood of a supervolcano type eruption is remote. Very very remote. It takes hundreds of thousands of years, sometimes close to a million years, for presures in large magma pools to reach a point thats condusive to super eruptions.

Hence the word "nascent". the articles does not suggest that there will be a super volcano in our life time.


As long as the pressure has outlets in the form of the average 1 eruption every 75years (or so) in the cascades, the conditions that form super-eruptions won't happen.

Probably true. But the past is not always a key to the future.


Now if every volcano in the cascades had been dormant for a few hundred throusand years, then there might be something to be concerened about. Right now there really isn't.

Perhaps so. But then we don't yet understand what triggers the formation of supervolcanoes in island arcs. Is it a long period of inactivity? Propagation of fractures that allows collapse of the lid over a very large magma chamber? Formation of a very large shallow magma resevoir? All of these?

Jon

Paracelsus
2009-Jun-17, 01:12 PM
if you go deep enough, there is a LOT of magma below any point on the surface of the earth- so the entire planet is a potential super volcano.

That's what I thought when I first read this article. Also, when using this technique, how do they separate out the conductive properties of all of the different layers? I'm trying to envision this 'magnetotelluric' technique at work and just can't. Is it like an EEG?

dgavin
2009-Jun-17, 02:29 PM
Not sematics at all. It is a historicval fact that plate tectonics was both a term and a coherent theory did not exist until 1967. Read any standard text book of the history of plate tectonics. 1967 was the critical year.

Semantics. Even Berkley sources support what I've been saying. http://www.ucmp.berkeley.edu/geology/techist.html


You are correct in saying that the water in the subducted slab acts as a flux and lowers the melting point. However you are incorrect regarding frictiona heating. this plays at best a very minor role in the generation of island arc melts. When a slab is subducted it is no longer part of the crust, but contained within the mantle. The water being given off by the subducted slab also acts as a flux in the mantle causing further melting. Hence the presence of igenous rocks of diverse compositions in island arcs.

Possibly, but we were discussing the Jaun-de-Fuca system which is not an island arc system. The function basis for it's magma generation is friction and superheated water.


There has been a vast amount of experimental petrology on a very wide range of real and theoretical magma compositions. I and S type granites, andesites, hydrous and anhydrous basalts, komatiites, have all been extensively studied.

Can you find a source that experimentaly tests the electircal properties water rich subduction zone magma? I haven't been able to find one.

As the the other postings, 'nascent' means having come into existent recently, or forming.

I think I have adaquately demontrated that there is no evidence of a supervolcano formation or forming in the cascades (excluding Newberry), either historically or currently.

Again it seems to me the research team is couching thier words to make much more of a situation that doesn't really exist.

Is it possible in the far future? I'm not arguing that point, but I have indicated there would be specific changes in the cacade volcanic system that would need to happen for that type of activity.

Even simultaneous eruptions in the cascades are not an indication of super-volcano's. At the time of Crater Lake's eruption, Mt. Shasta was also erupting.
The natives though it was some sort of 'war of the gods' and that Mt. Mazzama lost. There are also more resent example of multiple eruptions.

Gillianren
2009-Jun-17, 06:51 PM
Possibly, but we were discussing the Jaun-de-Fuca [sic] system which is not an island arc system.

Surely I would have noticed! Heck, a lot of our members would have noticed.

JonClarke
2009-Jun-17, 10:38 PM
Semantics. Even Berkley sources support what I've been saying. http://www.ucmp.berkeley.edu/geology/techist.html

Not semantics, but what actually happened. You need top read that article a bit more carefully. Pay particular attention to the last paragraph:

Not until the 1960's did Holmes' idea receive any attention. Greater understanding of the ocean floor and the discoveries of features like mid-oceanic ridges, geomagnetic anomalies parallel to the mid-oceanic ridges, and the association of island arcs and oceanic trenches occurring together and near the continental margins, suggested convection might indeed be at work. These discoveries and more led Harry Hess (1962) and R.Deitz (1961) to publish similar hypotheses based on mantle convection currents, now known as "sea floor spreading". This idea was basically the same as that proposed by Holmes over 30 years earlier, but now there was much more evidence to further develop and support the idea.

Then go and read some of the many excellent histories about the history of the plate tectonic revolution. There were three critical papers that proposed the concept of plate tectonics in 1967, I will get these from work today.


Possibly, but we were discussing the Jaun-de-Fuca system which is not an island arc system. The function basis for it's magma generation is friction and superheated water.

The Jaun de Fuca system? Do you mean the Juan de Fuca ridge? That is a mid ocean ridge (even though its nowhere near the middle of the ocean). Friction has nothing to do with ridge volcanism, mantel upwelling does.

Do you mean the Cascades? That is typical island arc volcanism (even though it is not currently an island but not the edge of a continent). That is subduction related, friction has nothing to do with magma generation there either.


Can you find a source that experimentaly tests the electircal properties water rich subduction zone magma? I haven't been able to find one.

For conductivity across a wide range of compositions see http://www.springerlink.com/content/84l4m0182088u685/

Electrical properties can also be predicted from other data. See http://www.springerlink.com/content/n7511w21213028rn/

Incidently here is a paper from 1992 discussing magnetotelluric mapping beneath Mount St Helens http://www.geo.mtu.edu/EHaz/VolcanoInstability_class/pdf/pallister/Pallister%20et%20al.,%201992.pdf


As the the other postings, 'nascent' means having come into existent recently, or forming.

I think I have adaquately demontrated that there is no evidence of a supervolcano formation or forming in the cascades (excluding Newberry), either historically or currently.

But you miss the whole point of the story that this new data suggests there might be one there in the future. Since we know very little about the early history of very large volcanoes this is an interesting possibility that the Cascades might represent such as system in embryo. Much like the Afar Triangle represents an coean ridge in embryo.


Again it seems to me the research team is couching thier words to make much more of a situation that doesn't really exist.

You are still not differentiating between the abstract (have you even read that yet?) and the NS story.


Is it possible in the far future? I'm not arguing that point, but I have indicated there would be specific changes in the cacade volcanic system that would need to happen for that type of activity.

Obviously, But it would be a very interesting discovery if we could get a glimpse into the very early development of veryt large volcanoes. Don't you think?


Even simultaneous eruptions in the cascades are not an indication of super-volcano's. At the time of Crater Lake's eruption, Mt. Shasta was also erupting.
The natives though it was some sort of 'war of the gods' and that Mt. Mazzama lost. There are also more resent example of multiple eruptions.

Since nobody has argued this, you are presenting a strawman.

jlhredshift
2009-Jun-17, 11:30 PM
Then go and read some of the many excellent histories about the history of the plate tectonic revolution.

The ones I would recommend would be:

Plate Tectonics; Oreskes

The Ocean of Truth; Menard

The Rejection of Continental Drift; Oreskes

and the last several chapters of:

Geology of the Nineteenth Century; Green

He spills over into the late twenties.

dgavin
2009-Jun-18, 01:50 AM
JonClarke


Not semantics, but what actually happened. You need top read that article a bit more carefully. Pay particular attention to the last paragraph:

"Not until the 1960's did Holmes' idea receive any attention. Greater understanding of the ocean floor and the discoveries of features like mid-oceanic ridges, geomagnetic anomalies parallel to the mid-oceanic ridges, and the association of island arcs and oceanic trenches occurring together and near the continental margins, suggested convection might indeed be at work. These discoveries and more led Harry Hess (1962) and R.Deitz (1961) to publish similar hypotheses based on mantle convection currents, now known as "sea floor spreading". This idea was basically the same as that proposed by Holmes over 30 years earlier, but now there was much more evidence to further develop and support the idea."

Then go and read some of the many excellent histories about the history of the plate tectonic revolution. There were three critical papers that proposed the concept of plate tectonics in 1967, I will get these from work today.

Sea Floor spreading was republished in 1961 and 1962, and there was even collaberative work before that in the 1950's when they finnaly knew about the oceanic rifts. Your acting like there was some decive date that Plate Tectonics sprug up out of no where right at 1967. When in reality the work on it began in the mid 50's, of which that expaned upon work from that 1920's that was largely ignored until then, continued through the mid 60's, and didn't even reach the mainstream of science education until the mid 1970's.

There wasn't some magical birth date for the work that became Plate Tectonics. So we -are- arguing semantics. The Mid Ocean Ridges were discovered and maped out in the 1950's, as well at the Magnetic Striping that indicated both pole revesals as well as allowing the growth of the oceanic plates to be determined. And it was the work of Hess and Dietz that was published in 1961 & 1962, but began years before that, that broght sea floor sreading into the vancular.

So an accurate statement of plate tectonics was, first proposed in 1920's and largely ignored, resurfaced in 1950 after physical data supported sea floor spreading, work continued through the 1960's when it became the accepted model, but did not enter the mainstream of science and education until the 1970's.

So you can't sit there and say there is a single date where the Plate Tectonics was born. Well you can if you choose to ignore all the development time of the Theory. 1967 may very well be when the name 'Plate Tectonics' was proposed as the new model name, but patently the work began in the 1950's, and was built on ignored thoeries from the 1920's.

You are simply at this point trying to prove my '1950s' statement wrong, by insititing on some specific date based on some specific papers and it seems to me that this whole 'Born on Date' is derailing the focus of the topic at hand.

So in an effort to end that I have a question for you.

Do you disagree that the work behind Plate Tectonics was started in the 1950's?



The Jaun de Fuca system? Do you mean the Juan de Fuca ridge? That is a mid ocean ridge (even though its nowhere near the middle of the ocean). Friction has nothing to do with ridge volcanism, mantel upwelling does.

Do you mean the Cascades? That is typical island arc volcanism (even though it is not currently an island but not the edge of a continent). That is subduction related, friction has nothing to do with magma generation there either.


To clearify I am talking about the Jaun-de-Fuca 'Subduction' and the fact that unlike island arc's. The models between the two are different. Providing one source here as evidence of the differences. http://www.geology.sdsu.edu/how_volcanoes_work/subducvolc_page.html

The Jaun-de-Fuca cascade system does not recieve any magma from the mantle like island arc's do (with the exception of the Newberry Cladera that is hot spot driven).


Appreciate the sources, I'll read over them. However I've already indicated that yes it would be a usefull tool in dispute. What is in dispute is that research teams interpration of them.


But you miss the whole point of the story that this new data suggests there might be one there in the future. Since we know very little about the early history of very large volcanoes this is an interesting possibility that the Cascades might represent such as system in embryo. Much like the Afar Triangle represents an coean ridge in embryo.


No the 'new data' just confirms that there is a primary pool of magma, that feeds the magma pools that are closer to the surface. Again this is nothing new. What is new is them suggesting the posibility of Giant Eruptions (which got redefined to Supervolcanos by the media).

That is pure speculation at this point and is not supported by any other evidence including but not limited to: Historical eruptive behavior and Siesmic readings.

But again, until some sort of transcript of thier presentation is made public, it will be hard to debate further.


You are still not differentiating between the abstract (have you even read that yet?) and the NS story.


I wouldn't of started this thread if I hadn't of read them. Why ask the obvious here?

And I haven't once brought the abstract up, or indicated that I thought it was wrong. So why should I Differentiate?

My beef is what one of the researchers was quoted as saying:
A really big, big eruption is possible if it is one of those big systems like Yellowstone," Hill says. "I don't think it will be tomorrow, but I couldn't try to predict when it would happen."

So we have one researcher that is already putting it into the category of a supervolcano even if he didn't come right out and say it. And that is what I'm saying is not suported by any other evidence.


Obviously, But it would be a very interesting discovery if we could get a glimpse into the very early development of veryt large volcanoes. Don't you think?


Yes I would definatley think it was interesting.

However again I feel they did not have enough evidence yet to suggest a tie in with a supervolcano at this point, so it should of never of been brought up. One magnetotellurics study is not enough evidence to begin proposing such a notion. So at best they are jumping the gun on conclusions.

Warren Platts
2009-Jun-18, 01:59 AM
No the 'new data' just confirms that there is a primary pool of magma, that feeds the magma pools that are closer to the surface. Again this is nothing new. What is new is them suggesting the posibility of Giant Eruptions (which got redefined to Supervolcanos by the media). Perhaps it would be useful to borrow a classification system from astronomy. There are ordinary stars, then there are Giant stars, but then there are also Super Giant stars. So one could have Giant Eruptions in the Cascades that are much bigger than run of the mill eruptions and still be incomparably smaller than a potential Supergiant Eruption that might occur at Yellowstone. :)

Gillianren
2009-Jun-18, 03:35 AM
To clearify I am talking about the Jaun-de-Fuca 'Subduction' and the fact that unlike island arc's.

No, you are talking about Juan de Fuca. "UA" and no hyphens.

JonClarke
2009-Jun-18, 10:08 AM
That's what I thought when I first read this article. Also, when using this technique, how do they separate out the conductive properties of all of the different layers? I'm trying to envision this 'magnetotelluric' technique at work and just can't. Is it like an EEG?

You use multiple base stations and long recording times. See

http://www.searchanddiscovery.net/documents/geophysical/christopherson/index.htm

http://userpage.fu-berlin.de/~mtag/MT-principles.html

http://www.tysonfisher.com/gallery/2949828_yDSNj/1/465773504_UYEBd/Medium

http://www.gns.cri.nz/news/release/volc.html



Jon

JonClarke
2009-Jun-18, 10:21 AM
The ones I would recommend would be:

Plate Tectonics; Oreskes

The Ocean of Truth; Menard

The Rejection of Continental Drift; Oreskes

and the last several chapters of:

Geology of the Nineteenth Century; Green

He spills over into the late twenties.

All good books. An excellent contemporary account by an eye witness is Hallam:

JonClarke
2009-Jun-18, 10:24 AM
Perhaps it would be useful to borrow a classification system from astronomy. There are ordinary stars, then there are Giant stars, but then there are also Super Giant stars. So one could have Giant Eruptions in the Cascades that are much bigger than run of the mill eruptions and still be incomparably smaller than a potential Supergiant Eruption that might occur at Yellowstone. :)

We have such a scale, the VEI http://en.wikipedia.org/wiki/Volcanic_Explosivity_Index - "supervolcanoes" are not officially on it, but any category 8 eruption could be called that.

JonClarke
2009-Jun-18, 11:48 AM
JonClarke

Sea Floor spreading was republished in 1961 and 1962, and there was even collaberative work before that in the 1950's when they finnaly knew about the oceanic rifts. Your acting like there was some decive date that Plate Tectonics sprug up out of no where right at 1967. When in reality the work on it began in the mid 50's, of which that expaned upon work from that 1920's that was largely ignored until then, continued through the mid 60's, and didn't even reach the mainstream of science education until the mid 1970's.

You really haven't read much of the history of the time, have you? Of course it did not spring from nowhere, no theory does. But the crystallisation of plate tectonics as a theory can be pin pointed very exactly to three key papers in 1967 by Morgan, McKenzie and LePichon. Before 1967 there was continental drift, seafloor spreading, even the expanding Earth. After 1967 plate tectonics very readily was established as the dominant theory.


There wasn't some magical birth date for the work that became Plate Tectonics. So we -are- arguing semantics. The Mid Ocean Ridges were discovered and maped out in the 1950's, as well at the Magnetic Striping that indicated both pole revesals as well as allowing the growth of the oceanic plates to be determined. And it was the work of Hess and Dietz that was published in 1961 & 1962, but began years before that, that broght sea floor sreading into the vancular.

Again, you are steadfastly ignoring the reality. In 1965 Wilson used the word "plate" in the modern meaning, but applied it only to the area of Californis. In April 1967 Morgan in a conference described all the elements of plate tectonics theory as applied to the six main plates, but used the term "block" rather than "plate". McKenzie later that year used the word "plate tectonics" in a paper but focussed on the Pacific Plate (although mentioning it had gloval application). Early 1968 Morgan published his full paper describing a mathematicvally rigorous global system of 6 "blocks" (plates) on a sphere. Later in 1968 LePichon published a map of 20 major and minor plates and described their motions, pretty much as we know them now. You can equivocate as much as you like but 1967 was the critical year for the theory as a choherent entity.

This does not inavlidate the work of Dietz, Holden, Bullard, Hess, Runcorn, and many others in documenting apparent polar wander, seafloor pagnetic anomalies, and many other important observations. Or the greats of du Toit, Holmes, Carey, Kinf, and Wegener. But none of them synthesised a global theory of plate tectonics. McHenzie, Morgan, and LePichon did


So an accurate statement of plate tectonics was, first proposed in 1920's and largely ignored, resurfaced in 1950 after physical data supported sea floor spreading, work continued through the 1960's when it became the accepted model, but did not enter the mainstream of science and education until the 1970's.

Nobody proposed plate tectonics in the 1920s. There was no plates, no spreading centres, no subduction zones, no transform faults known. The basic data wasn't there. All that were was available was the theory of mantle convection and the possibility of continental drift. Neither on their own equals plate tectonics.

Nobody proposed plate tectonics in the 50s. The discover of seafloor spreading and other features of the ocean floor inspired renewed thinking, but not plate tectonbics. The data did not yet exist.


So you can't sit there and say there is a single date where the Plate Tectonics was born. Well you can if you choose to ignore all the development time of the Theory. 1967 may very well be when the name 'Plate Tectonics' was proposed as the new model name, but patently the work began in the 1950's, and was built on ignored thoeries from the 1920's.

All the evidence says there was a very specific period of one or two years when the theory did emerge. Read the histories. Talk to the people who were there. Saying that plate tectonics started in the 1920s is like saying that the germ theory of disease started in the 14th century. It is true there were hypotheses and observations regarding a germ theory of disease over several centuries, but the emergence of a scientifically rigourous germ theory had to wait until the period 1860-1890, with the work of Pasteur, Koch, and Lister.

As for ignored theories, Holmes, Wegener, du Toit, King, and Carey may have been ignored in the US. They were not ignored in the rest of the world.


You are simply at this point trying to prove my '1950s' statement wrong, by insititing on some specific date based on some specific papers and it seems to me that this whole 'Born on Date' is derailing the focus of the topic at hand.

You are the one persisiting in this error. All you need to do is recongise what all the historians and contemporary accounts say and move on.


So in an effort to end that I have a question for you.

Do you disagree that the work behind Plate Tectonics was started in the 1950's?

Let's see, I have mentioned the contributions of Wegener, Hess, Dietz, Holden, Bullard, Carey, du Toit, Holmes, and King. What do you think?



To clearify I am talking about the Jaun-de-Fuca 'Subduction' and the fact that unlike island arc's. The models between the two are different. Providing one source here as evidence of the differences. http://www.geology.sdsu.edu/how_volcanoes_work/subducvolc_page.html

The Jaun-de-Fuca cascade system does not recieve any magma from the mantle like island arc's do (with the exception of the Newberry Cladera that is hot spot driven).

Thanks for that. The second paragraph says:

The crustal portion of the subducting slab contains a significant amount of surface water, as well as water contained in hydrated minerals within the seafloor basalt. As the subducting slab descends to greater and greater depths, it progressively encounters greater temperatures and greater pressures which cause the slab to release water into the mantle wedge overlying the descending plate. Water has the effect of lowering the melting temperature of the mantle, thus causing it to melt. The magma produced by this mechanism varies from basalt to andesite in composition. It rises upward to produce a linear belt of volcanoes parallel to the oceanic trench, as exemplified in the above image of the Aleutian Island chain. The chain of volcanoes is called an island arc. If the oceanic lithosphere subducts beneath an adjacent plate of continental lithosphere, then a similar belt of volcanoes will be generated on continental crust. This belt is then called a volcanic arc, examples of which include the Cascade volcanic arc of the U.S. Pacific northwest, and the Andes volcanic arc of South America. (emphasis mine)


Appreciate the sources, I'll read over them. However I've already indicated that yes it would be a usefull tool in dispute. What is in dispute is that research teams interpration of them.

It is hard to dispute the interpretation of the researchers when all we have is a 138 word abstract and a short popular article that may be only loosely based on it.


No the 'new data' just confirms that there is a primary pool of magma, that feeds the magma pools that are closer to the surface. Again this is nothing new. What is new is them suggesting the posibility of Giant Eruptions (which got redefined to Supervolcanos by the media).

[QUOTE] Acxtually a single shared magma pool at mid crustal depths for the Cascades is a new idea. The nascent giant eruption may be an implication that Hill and his team thinks is possible, it may be journalistic liscence from NS.

[QUOTE]That is pure speculation at this point and is not supported by any other evidence including but not limited to: Historical eruptive behavior and Siesmic readings.[QUOTE]

More to the point does nay existing data contradict it?

[QUOTE]But again, until some sort of transcript of thier presentation is made public, it will be hard to debate further.[QUOTE]

You don't normally get transcripts of conference talks. But a paper should be coming out in the next year or so I imagine.

Hill et al. certainly have been busy.

http://www.agu.org/cgi-bin/wais?mm=V43E-2190

http://www.agu.org/cgi-bin/wais?mm=V43E

http://gsa.confex.com/gsa/2007CD/finalprogram/abstract_121016.htm

http://www.agu.org/cgi-bin/SFgate/SFgate?

[QUOTE]I wouldn't of started this thread if I hadn't of read them. Why ask the obvious here?

Because it was not obvious from your comments that you had read it, understood it, and differentiated betwene the authro's work and the NS report of it.


And I haven't once brought the abstract up, or indicated that I thought it was wrong. So why should I Differentiate?

Because you made a balnket statement of "complete hog-wash" in the OP. If you think it is the original abstract then say so. If it is the story, make that clear.


My beef is what one of the researchers was quoted as saying:

So we have one researcher that is already putting it into the category of a supervolcano even if he didn't come right out and say it. And that is what I'm saying is not suported by any other evidence.

New evidence can radically change how we interpret old evidence. What evidence is there now to that says that this possibility is wrong?


However again I feel they did not have enough evidence yet to suggest a tie in with a supervolcano at this point, so it should of never of been brought up. One magnetotellurics study is not enough evidence to begin proposing such a notion. So at best they are jumping the gun on conclusions.

How do you know they haven't got enough evidence to warrent this possibility?

Jon

jlhredshift
2009-Jun-18, 12:31 PM
IMHO the definitive "birth" of Plate Tectonics is the mathematical application of Euler poles which allowed quantification of plate movement.

See:

Simple Euler Poles (http://www.earth.northwestern.edu/people/seth/demos/BRICK/brick.html)

Euler Poles - Wiki (http://en.wikipedia.org/wiki/Euler's_rotation_theorem)

dgavin
2009-Jun-18, 03:31 PM
JonClarke:


You are the one persisiting in this error. All you need to do is recongise what all the historians and contemporary accounts say and move on.

No I don't.

Just because your version of history doesn't match mine, is a matter of interpretation and semantics. You see the publication date of three papers as the definative answer. I see the Mantle Convection and Continetal Drift of the 20's, combined with the Seafloor Speading of the 50's, as the beginning of Plate Tectonics.

We'll obviously never agree on this, so lets drop it shall we?


Let's see, I have mentioned the contributions of Wegener, Hess, Dietz, Holden, Bullard, Carey, du Toit, Holmes, and King. What do you think?

My second sentence in above paragraph answered this. We both acknowkege the prior work leading too plate techtonics. No reason to ask 'What I Think' as I've metnioned it many times in this debate.


Thanks for that. The second paragraph says:

The crustal portion of the subducting slab contains a significant amount of surface water, as well as water contained in hydrated minerals within the seafloor basalt. As the subducting slab descends to greater and greater depths, it progressively encounters greater temperatures and greater pressures which cause the slab to release water into the mantle wedge overlying the descending plate. Water has the effect of lowering the melting temperature of the mantle, thus causing it to melt. The magma produced by this mechanism varies from basalt to andesite in composition. It rises upward to produce a linear belt of volcanoes parallel to the oceanic trench, as exemplified in the above image of the Aleutian Island chain. The chain of volcanoes is called an island arc. If the oceanic lithosphere subducts beneath an adjacent plate of continental lithosphere, then a similar belt of volcanoes will be generated on continental crust. This belt is then called a volcanic arc, examples of which include the Cascade volcanic arc of the U.S. Pacific northwest, and the Andes volcanic arc of South America.

On this one I'll stand corected, upto a point. Friction is not the main cause of magma generation. From one of my own sources.


Unfortunately, some books say that both the earthquakes and the volcanoes are caused by friction - rubbing of the top of the downgoing plate against the bottom of the overlying plate. This may be the cause of some of the shallowest subduction-zone earthquakes but it is not the cause of the intermediate or deep ones, and it is definitely NOT the way magma is produced.

...




So yes I evidently have read a few of the wrong books. Considering that they are textbooks though i think that is somewhat excusable.

However I -am- right in that the magma is produced in the Continental plates lithosphere. In inland arc systems is produced partly in the lithosphere and partly from the ansthenospere.

As that same source (and other sources) consider the plates lithosphere part of the mantle in some cases, and part of the plate at other times, there seems to some ambiguity to what one means by Mantle. I was considering the lithosphere as part of the plate and not the mantle. So my ammended statement is that the melting occurs in the continetal plate's lithosphere.


Acxtually a single shared magma pool at mid crustal depths for the Cascades is a new idea.

No it isn't. I've even posted a model some years ago on this vary forum based on a mid debth pool. The idea has been around since the 80's when certain siesmographs were picking up the activity from St. Helens eruptions, via some sort of common footprint as it was called then. Siemic Tomology has since shown that it was down there. This research teams results just help to confirm it.

This post here http://www.bautforum.com/957809-post97.html dated 28 march 2007 most definately shows this is not a New idea.


More to the point does nay existing data contradict it?


Never said anythign contridicted the existance of a pool. What i'm saying is 1. It is not a new idea. And 2. At least one researcher, and most definately NewScientist are premature in making a direct correlation with Yellowstone.

My main beef with that correlations that is the magma's are of entirely differnt compositions and thickness. Supervolcano's tend to be present where there is thinner (hot spot, island arc, rift zone) and more fluid magma's. The cascade's magma is much thicker, and as such less condusive to such a senerio.


New evidence can radically change how we interpret old evidence. What evidence is there now to that says that this possibility is wrong?


If the mid plate pool was going to produce such a eruption or even if it was changing in volume, this would be preceded by a general uplift of the region roughly the size of the pool. There is no ISARS data that shows any general uplift of such a large region.

While there is localized uplift from the pools of magma's closer to the surface.


Because you made a balnket statement of "complete hog-wash" in the OP. If you think it is the original abstract then say so. If it is the story, make that clear.

I have no problem saying the Story is the main source of the Hog Washery, and atleast one researcher correlating it to Yellowstone when interviewed for the story.

Thanks for those links on his worrk, going to take a look at them.


How do you know they haven't got enough evidence to warrent this possibility?


Because magma in the cascade subduction system is vastly different then that in a hot spot system. It doesn't behave the same, it doesn't flow the same, and it's properties are not condusive to large supervocanic eruptions. Again not saying it's impossible, just that I don't agree with that correleation with Yellostone, for many many resons alread previously stated.

JonClarke
2009-Jun-20, 12:36 AM
Just because your version of history doesn't match mine, is a matter of interpretation and semantics. You see the publication date of three papers as the definative answer. I see the Mantle Convection and Continetal Drift of the 20's, combined with the Seafloor Speading of the 50's, as the beginning of Plate Tectonics.

The beginning (or better yet the antecedents) of plate tectonics, yes. But not plate tectonics itself. There was no coherent plate tectonic theory until 1967.


We'll obviously never agree on this, so lets drop it shall we?

If you won't recognise reality in a simple matter of the date when a theory was postulated, then it does not bode well for other discussions.


So yes I evidently have read a few of the wrong books. Considering that they are textbooks though i think that is somewhat excusable.

Even textbooks can be wrong. I have contributed to some, so should know!


However I -am- right in that the magma is produced in the Continental plates lithosphere. In inland arc systems is produced partly in the lithosphere and partly from the ansthenospere.

S-type granitic magmas are produced in continental lithosphere. Most arc magmas are produced in the subducted slab, which is no longer part of the lithosphere, and in the adjacent mantle.


As that same source (and other sources) consider the plates lithosphere part of the mantle in some cases, and part of the plate at other times, there seems to some ambiguity to what one means by Mantle. I was considering the lithosphere as part of the plate and not the mantle. So my ammended statement is that the melting occurs in the continetal plate's lithosphere.

Arc magmas mostly are not generated in the in the continental lithsophere.


No it isn't. I've even posted a model some years ago on this vary forum based on a mid debth pool. The idea has been around since the 80's when certain siesmographs were picking up the activity from St. Helens eruptions, via some sort of common footprint as it was called then. Siemic Tomology has since shown that it was down there. This research teams results just help to confirm it.

This post here http://www.bautforum.com/957809-post97.html dated 28 march 2007 most definately shows this is not a New idea.

Mid crustal magma books beneath individual volcanoes has been known for a long, and we did not need crustal tomography to show it. Seismic tomography confirmed what was already suspected. The mid crustal pool in your animation refers to a single volcano. What Hill et al. claim is that there is a common source to all the volcanoes in the Cascades. Maybe others have suggested this before. But their new data is certainly supportive of it.



Never said anythign contridicted the existance of a pool. What i'm saying is 1. It is not a new idea. And 2. At least one researcher, and most definately NewScientist are premature in making a direct correlation with Yellowstone.

If 1) then they have provided additional confirmation of it. Whjat is so henious about this? If 2) why is suggesting a possible link to very large eruptions premature? Aren't scientists suyp[posed to talk about possible links and implications? Aren't the scientific media supposed to communicate interesring new possibilities to the public?


My main beef with that correlations that is the magma's are of entirely differnt compositions and thickness. Supervolcano's tend to be present where there is thinner (hot spot, island arc, rift zone) and more fluid magma's. The cascade's magma is much thicker, and as such less condusive to such a senerio.

That's not right. Supervolcanoes are associated with very thick and viscous magmas, not thin, runny ones. Rhyolites, dacites and andesites rather than basalts. Yellowstone has rhyolites, dacites, and andesite. The Taupo volcanic zone (which has had multiple super volcano eruptions is mostly rhyolites, dacites, and andesite. The Cascade volcanoes are, guess what? Rhyolites, dacites, and andesite.



If the mid plate pool was going to produce such a eruption or even if it was changing in volume, this would be preceded by a general uplift of the region roughly the size of the pool. There is no ISARS data that shows any general uplift of such a large region.

That's only in the short term, a few years at most. If the Casades produce a super voclano, it might not be for hundreds of thousands of years.


I have no problem saying the Story is the main source of the Hog Washery, and atleast one researcher correlating it to Yellowstone when interviewed for the story.

I don't think you have shown sufficient understanding of the subject to be able to declare it hogwash.

You did not know what magnetotellurics was. You don't understand the oprigin of magmas in subduction xones, not have you correctly stated the compsotion of magmas associated in super volcanoes, whether associated with hot spots or with volcanic arcs.

Given this it is fine to be sceptical, but not dogmatic. Do more reading. Talk to people more familiar with the subject.


Because magma in the cascade subduction system is vastly different then that in a hot spot system. It doesn't behave the same, it doesn't flow the same, and it's properties are not condusive to large supervocanic eruptions. Again not saying it's impossible, just that I don't agree with that correleation with Yellostone, for many many resons alread previously stated.

You keep assuming that supervolcanoes are associated only with hot spots. They are not. In fact hot spot-related supervolcanoes are in the minority. Yellowstone is one of the few. Those of the Taupo volcanic zone are in a volcanic arc. Taal is in a volcanic arc. Toba is in a volcanic arc. You are wrong.

Jon

dgavin
2009-Jun-20, 04:54 AM
Jon:


The beginning (or better yet the antecedents) of plate tectonics, yes. But not plate tectonics itself. There was no coherent plate tectonic theory until 1967.

If you won't recognise reality in a simple matter of the date when a theory was postulated, then it does not bode well for other discussions.

As you have seem to taken this to a level of credibility, allow me to retort in kind.

I had said:


Third, the Magma pocket at 15km to the base of the plates has been known about for years.

A similar idea was original proposed in the 50's before seismic tomology was readily used, back then there was a standing theory that there was a broken off piece of jaun-de-fuca plate that traped itself in the melt zone, and was slowly pulverized and melted over millions of years, the pieces of which, still solid in the melt zone tended to act a bit like giant ball bearings.


I never once actually said Plate Tectonics was 'invented' in the 50's. I was talking about an old idea of a 'ball bearing' effect in the plates in a large magma pool.

You made some sort of logical leap at a diagonal angle that I was talking about plate tectonics, which I wasn't. At all. I boldfaced the subject of the original sentence, and the continuation as you seem to have missed it.

You replied this:


Plate tectonics was not known in the 1950's. Even continental drift was ridiculed in the US.

To which I replied:


That is a misleading statement, as early as 1920's the plate junction theories in seafloors was proposed, followed by the 1928 mantle convection currents theories. In 1956 they had the first evidence that the continental drift and expanding earth models were not correct, and proponents of both those theories beginning starting a collaborative work on what would become Plate Tectonics in the 1960's.

So 1950's is accurate, unless you want to discount the development time Plate Tectonics took.


I even Said Plate Tectonics was from the 60's, did you perhaps miss that?

All I was saying all along is that I consider a "hard date" as misleading, as the theory came about from the seafloor spreading research of the mid/late fifties and also earlier research which you seem to agree with.

I then Replied:


So 1950's is accurate, unless you want to discount the development time Plate Tectonics took.

So once again I was never saying the name of "Plate Tectonics" or the Theory was ratified in the 1950's, just that is where it got its kick off so to speak.

That was another incorrect assumption about what I was saying.

Also you took another statement of mine "A magneto what?" to mean that I didn't know what it was. I knew of magnetotellurics in application to mining activities.

That first sentence was intended as a derisive statement implying the difficulty of pronouncing the word.

However I quite happily admit that none of my sources on volcanology have made public research from magnetotelluric studies of volcanoes readily available. And I think I mentioned this once before. Just to make sure this isn't taken out of context; also I am not referring to short abstracts woefully lacking in substance either.


Arc magmas mostly are not generated in the in the continental lithsophere.

I never disagreed with this either, except in application to the Cascade Subduction zone which as shown in previous sources, the magma is produced in the overlying plates lithosphere.

Source 1: http://www.geology.sdsu.edu/how_volc...volc_page.html
Source 2: http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/map_juan_de_fuca_subduction.html (additionally this one also proves I was also correct in calling it the Jaun de Fuca system when referring to the subduction volcanism)
Source 3: http://walrus.wr.usgs.gov/tsunami/cascadia.html
Source 4: http://en.wikipedia.org/wiki/Cascadia_subduction_zone
Source 5: http://vulcan.wr.usgs.gov/Glossary/StratoVolcano/description_composite_volcano.html
Source 6: http://geology.com/press-release/depth-of-magma-formation/
Source 7: http://www.colorado.edu/GeolSci/Resources/WUSTectonics/PacNW/juan_de_Fuca_advanced.html (source also supports that you cannot apply other subduction zone constraints or normal concepts to the Cascade region)
Source 8: http://gsc.nrcan.gc.ca/geodyn/cascadia_e.php
Source 9: http://adsabs.harvard.edu/abs/2004AGUFM.S51B0167R
That last one is also a killing blow for the super-volcano idea, another study magnetotellurics of the very same region in this subect, as it calls the zone "It probably represents a zone of aseismic slip". A much more reasonable explanation then a potential super-volcano if you ask me.


That's not right. Supervolcanoes are associated with very thick and viscous magmas, not thin, runny ones. Rhyolites, dacites and andesites rather than basalts. Yellowstone has rhyolites, dacites, and andesite. The Taupo volcanic zone (which has had multiple super volcano eruptions is mostly rhyolites, dacites, and andesite. The Cascade volcanoes are, guess what? Rhyolites, dacites, and andesite.

Actually I was right up to a certain point. The problem here is again in your reading more into what I had said. I used the word thinner, meaning less thick, not as thick. I did not say "thin, runny ones". However I think I may have unintentionaly impyied that in my next sentence.


That's only in the short term, a few years at most. If the Casades produce a super voclano, it might not be for hundreds of thousands of years.

While this is isn't exactly a Straw-man argument, it is rather circular reasoning. For example I could say that in the next 1 billion years that life will evolve on another planet someplace. And I'd likely be about 99.9% correct in that statement.

A far as a super-volcano forming in the next 200,000 yeas in the St. Helen's or adjacent Regions, I'd give that about a 1% likely hood at this point.


I don't think you have shown sufficient understanding of the subject to be able to declare it hogwash.

That's because you have been misreading, or reading too much into somethings I have said.

I think what is behind the misreading is likely due to being something akin to "Why, that self proclaimed amateur vulcanologist has the audacity to decry something a trained geologist says?!" type of reaction on your part, brought on by my debunking and derisiveness to Hill's statement about it being Yellowstone like.

I want you to understand that I am not decrying your field of specialty or your knowledge of it.

I have not once in this thread called your credentials into question, as I know you are a trained Geologist. I might add some posters including myself even asked your input on matters in other threads and you did not react in this manner, instead you were helpful and assisted us.

I am somewhat focused in my amateur volcanology hobby on the Cascade/Juan de Fuca subduction zone.

I think I have demonstrated that I do have a very good foundation of the Cascade/Juan de Fuca system, and of a decent one of vulcanologist in general, over the years here with my volcano threads, discussions, and informational updates. Which I haven't seen you ever say you have issues with before.


You did not know what magnetotellurics was..

I covered that already once, so I won't get into it again. Assumption.


You don't understand the oprigin of magmas in subduction xones, not have you correctly stated the compsotion of magmas associated in super volcanoes, whether associated with hot spots or with volcanic arcs.

With the exception of the friction, which I admitted too (as I was parroting old textbooks) I think I have done quite well proving my points.

I never stated the exact compositions of various known supervolcano's because: No one patently asked me to do that. So your statement "not have you correctly stated the compsotion of magmas associated in super volcanoes, whether associated with hot spots or with volcanic arcs" is a Straw-man argument of your own.

I was intentionally trying to keep this focused on the Juan de Fuca or Cascadia subduction system as I did not want to get into such an esoteric and somewhat unrelated conversion about all subduction zones. Again my point being here to debunk a fear mongering type of article.


Given this it is fine to be sceptical, but not dogmatic.

I'm not the the one that brought "Dogma" into this. That came into it as it seems you kept misreading what exactly I was saying. On quite a few occasions.


Do more reading. Talk to people more familiar with the subject.

Who said I didn't do that? I learned a bit about Pink Dactite's by emailing a vulcanologist that works for USGS directly. I do talk to specilaists in the Cascade system on occasions.

So for the final time, my issues is not with Hill or his training, or you or yours. It's with his (likely off handed) comment of that Yellowstone correlation based on (what I assume is a single study for now) research results, when other studies from both seismology, tomology and the very same technique obviously have far more reasonable conclusions.

I've been posting against what I considered Fear Mongering tactics by NewScientist. Which has ran rampant over the media since the day they published it. Even the Oregonian newspaper had to print a bit of a rebuttal article to it as they felt is was inaccurate and it was cause somee amount of concern in the PNW. They also had a local cascade geologist help them on that rebuttal.

Because of peoples reaction to that Hog-Wash NewScientist article (and that's just another reason I will say, and go on saying that) such a -public- correlation to Yellowstone was vastly inappropriate, and premature at this point.

However as it's likely my initial derisiveness of that article may have led to this whole debate and some of the misunderstands that happened, for that I will apologize to you Jon.

JonClarke
2009-Jun-24, 11:20 AM
Sorry for the tardy reply, real life intervened, preventing me from lengthly comments on this board.



As you have seem to taken this to a level of credibility, allow me to retort in kind.

I never once actually said Plate Tectonics was 'invented' in the 50's. I was talking about an old idea of a 'ball bearing' effect in the plates in a large magma pool.

You made some sort of logical leap at a diagonal angle that I was talking about plate tectonics, which I wasn't. At all. I boldfaced the subject of the original sentence, and the continuation as you seem to have missed it.

Since plates were not known in the 1950's it is misleading to talk about plates in the context of the science of the period.


I even Said Plate Tectonics was from the 60's, did you perhaps miss that?

If so, why did you write as early as 1920's the plate junction theories in seafloors was proposed?


All I was saying all along is that I consider a "hard date" as misleading, as the theory came about from the seafloor spreading research of the mid/late fifties and also earlier research which you seem to agree with.

And all I am saying that that plate tectonics as a coherent theory under that name originated in 1967.


Also you took another statement of mine "A magneto what?" to mean that I didn't know what it was. I knew of magnetotellurics in application to mining activities.

Fair enough. But in future it might not be a good idea to feign ignorance - people might confuse it with the real thing.


However I quite happily admit that none of my sources on volcanology have made public research from magnetotelluric studies of volcanoes readily available. And I think I mentioned this once before.

Fair enough too, but there is a lot of published literature on magnetotelluric studies of volcanoes.


Just to make sure this isn't taken out of context; also I am not referring to short abstracts woefully lacking in substance either.

Most new research is first presented in short abstracts woefully lacking in substance - that is not the fault of the abstract or the researchers, it is the nature of the conference system.


I never disagreed with this either, except in application to the Cascade Subduction zone which as shown in previous sources, the magma is produced in the overlying plates lithosphere.

Except it is still wrong. Magmas are not generated in the lithosphere, except where mantle melts heat the lithosphere past its melting point.


ttp://www.colorado.edu/GeolSci/Resources/WUSTectonics/PacNW/juan_de_Fuca_advanced.html[/URL] (source also supports that you cannot apply other subduction zone constraints or normal concepts to the Cascade region)

Except that the Cascades regions is where much of out understanding of such systems was developed. It has its unque features, but so does every volcanic arc. It also has features common to others.


Source 9: http://adsabs.harvard.edu/abs/2004AGUFM.S51B0167R
That last one is also a killing blow for the super-volcano idea, another study magnetotellurics of the very same region in this subect, as it calls the zone "It probably represents a zone of aseismic slip". A much more reasonable explanation then a potential super-volcano if you ask me.

Except for the fact that study is five years older than the recent work by Hill and may well be superceded by new information.


Actually I was right up to a certain point. The problem here is again in your reading more into what I had said. I used the word thinner, meaning less thick, not as thick. I did not say "thin, runny ones". However I think I may have unintentionaly impyied that in my next sentence.

You said: Supervolcano's tend to be present where there is thinner (hot spot, island arc, rift zone) and more fluid magma's. The cascade's magma is much thicker, and as such less condusive to such a senerio. Maybe there is a missing "crust" after the first thinner? But it is still not right. The crust is thin under Yellowstone. It isn'tr under Taupo or Toba.


While this is isn't exactly a Straw-man argument, it is rather circular reasoning. For example I could say that in the next 1 billion years that life will evolve on another planet someplace. And I'd likely be about 99.9% correct in that statement.

It's like saying the Afar rift zone may develop into an ocean in a few hunedred thosuand years. It's a prediction based on a particular interpretation of the evidence. It may be right, it may be wrong, but its is not circular.



A far as a super-volcano forming in the next 200,000 yeas in the St. Helen's or adjacent Regions, I'd give that about a 1% likely hood at this point.

Over what time scale? Maybe you are right, but you should be prepared for the possibility that new data may change this. And new data forst gets presented in conferencves as short abstracts.


That's because you have been misreading, or reading too much into somethings I have said.

I think what is behind the misreading is likely due to being something akin to "Why, that self proclaimed amateur vulcanologist has the audacity to decry something a trained geologist says?!" type of reaction on your part, brought on by my debunking and derisiveness to Hill's statement about it being Yellowstone like.

I want you to understand that I am not decrying your field of specialty or your knowledge of it.

I have not once in this thread called your credentials into question, as I know you are a trained Geologist. I might add some posters including myself even asked your input on matters in other threads and you did not react in this manner, instead you were helpful and assisted us.

It is not about me at all, it is your calling new and interesting work Hogwash without sufficient evidence to do so


I never stated the exact compositions of various known supervolcano's because: No one patently asked me to do that. So your statement "not have you correctly stated the compsotion of magmas associated in super volcanoes, whether associated with hot spots or with volcanic arcs" is a Straw-man argument of your own.

It is not a straw man. You specifically said: Supervolcano's tend to be present where there is... more fluid magma's. The cascade's magma is much thicker, and as such less condusive to such a senerio.

That is a clear statement that the composition of the Cascades volcanoes is different to that of super volcanoes. It is not.


I was intentionally trying to keep this focused on the Juan de Fuca or Cascadia subduction system as I did not want to get into such an esoteric and somewhat unrelated conversion about all subduction zones.

You can't discuss supervolcanoes without discussing the broader context.


Again my point being here to debunk a fear mongering type of article.

How is simply mentioning the possibility that there might one day be a super volcano in the Cascades fear-mongering?


I'm not the the one that brought "Dogma" into this. That came into it as it seems you kept misreading what exactly I was saying. On quite a few occasions.

If the cap fits, wear it.


So for the final time, my issues is not with Hill or his training, or you or yours. It's with his (likely off handed) comment of that Yellowstone correlation based on (what I assume is a single study for now) research results, when other studies from both seismology, tomology and the very same technique obviously have far more reasonable conclusions.

Any my issue with you is that you assume that Hill and his team have not taken this into account and, on the basis of very little information, dismiss it as "hogwash" and fear mongering". If that is not having issues is not with Hill or his training then what is?



I've been posting against what I considered Fear Mongering tactics by NewScientist.

Again, how is it fear mongering? Did they say millions will be killed? Did they say that people should flee? Or should they not report an interesting story just because some people in the Cascades might get upset?


Which has ran rampant over the media since the day they published it.

Rampant mean how many stories?


Even the Oregonian newspaper had to print a bit of a rebuttal article to it as they felt is was inaccurate and it was cause somee amount of concern in the PNW. They also had a local cascade geologist help them on that rebuttal.

You mean this article? http://www.oregonlive.com/news/index.ssf/2009/06/a_supervolcano_or_just_a_lot_o.html

It does not really add anything and they did not even bother to contact Hill you is just an email or even a phone call away.

If people live in the PNW they should accept the reality of the fact that there willm be volcanic neruptions, regardless of scale.


Because of peoples reaction to that Hog-Wash NewScientist article (and that's just another reason I will say, and go on saying that) such a -public- correlation to Yellowstone was vastly inappropriate, and premature at this point.

Yellowstone is the best known supervolcano to the public and therefore it is entirtely appropirate to mention iot as an example. I doubt if many people in the Cascades have hear of Taupo or Toba.

When is it premature to run such a story? Hill and his team gave a talk at a conference in which the presented the latest results on their owngoing research. Is that premature. NS is a specialist science news magazine. They communicate interesting results from round the world of the latest research. How is this premature? Should they wait until it is set in textbooks before they report on it?


However as it's likely my initial derisiveness of that article may have led to this whole debate and some of the misunderstands that happened, for that I will apologize to you Jon.

This is certainly true. Apology accepted.

Jon

dgavin
2009-Jun-24, 02:27 PM
Jon:

As far as Rampant:

It's been carried on quite a few legitimate papers and TV stations.

If you want to see how bad it is then I'd suggest a google search on it for starters.

We are not goin to agree on the Fear Mongering aspect of it most likely. I live and work in the NW so have seen first hand the impact of that press release.

For lack of a better explaination, what was said was premature. It would be akin to yelling fire in a movie theater because someone lit up a cig.

Such a bold statement even if science supports it, should not of been said without a full public release of the science, after peer review process. Again the point being I'm not arguing what Hill presented at the conference, but what he said to the NewScientist journalist.

The geologist that was consulted on this rebuttal http://www.oregonlive.com/news/index.ssf/2009/06/a_supervolcano_or_just_a_lot_o.html was a lot more diplomatic then I was I'll admit. But it does support what I'm saying. The readings are intresting, but too soon to really say what they are.

If you feel that Dr. Hill should be written about the effects of what the press release caused, then I'd be happy to do just that.