GeologyRocks

If this is the one available on DVD, I use it with my GCSE geology group. A real eyeopener.

Sadly vulcanologists are frequent casualties of the volcanic activity and associated risks

 see http://www.volcano.si.edu/reports/bulletin/contents.cfm?issue=special

I agree it is a very dangerous job.  But it must be very exciting in so many ways too, not least because you can potentially help save people's lives.

The issue of this particular volcano did creep me out though.  A ticking time bomb.  I wonder what else we common people don't know about...

'Man' has never experienced a supervolcano, and its well overdue statistically.  I read somewhere that it is thought that Yellowstone would produce enough ash to cover the whole of North America in 10 meters of ash. 

Just think of the consequences of that!  It might be better to be on top of it when it does blow.  At least it would be quick.

However, do send in a blog of your experience to GR before you drop off the twig.  I know we would all be very interested!!!

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

LOL will do John!

"Man" has never experienced one? How about the Toba supervolcano?

That's widely recognised as one of the most powerful erruptions the earth has ever seen, and we believe that it bottlenecked the human population.

I've always said if I knew that Yellowstone was going to blow I'd go and have a look, If I'm going to die anyway I want to see something pretty before I do.

Leah 

Oh yes, Toba was mentioned on the documentary.  Still, I guess there's nothing we can do if it erupts, so as you both say, be there when it happens

I didn't think that Toba  was classed as a supervolcano.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

I had class last night, and my professor mentioned the hot spots there!

lol sounds like this thread has a few hot spots

It was deffinitly a super erruption, but you're right, has it ever been classed as a super-volcano? I found this earlier;

http://books.google.co.uk/books?hl=en&lr=&id=9CRV7JDhW0sC&oi=fnd&pg=PA71&dq=toba+supererruption&ots=_iwmKS_26o&sig=xl4c1cZyKNt-6w1mDRgKSH2E9yc#v=onepage&q&f=false 

As this thread has sparked a little intrest inside of me. It's worth a read, especially from an anthropological point of view
This is what GR has been missing, good old geological debate

Leah 

I'm in Leah's corner on this one.

I was always taught Toba was a super-volcano. I have the book Krakatoa: The Day the World Exploded: August 27, 1883 in a box somewhere in the house, I'm sure that mentions comparative figures, and mentions Toba as a super-volcano too.

What would it be termed if it wasn't a supervolcano?

A super erruption caused by an explosive mantle plume episode? as it was beneath continental crust (I'm just guessing here) Hawaii is under a hotspot but it's not classed as a supervolcano, I'd guess because it's continuos and due to the mafic melt it's not explosive. But My specialism is not petrology by any means I'm a palaeobiologist so please don't take me as gospel

Leah 

Well that sounds logical enough

What made you choose palaeobiology?

I have a bit of a fascination with dead things :p 

I was always in love with Dinosaurs and mass extinctions and as my inoversity career progressed I realsied that the interesting things were the dead things and what we could tell from them, so I've done a bit of vertebrate, invertebrate, micro and geochem and I'm trying to stick to that field of things, but it's looking increasingly likely that when I get to Oz I'll be moving into Gold Exploration for a few years to try and fund a PhD as there's no funding available at the moment for what I'd really like to do

Leah 

Sorry about the funding.  Happens to everyone at some point I reckon.  Out of interest, why are you moving to Oz?

Because unless I can get an academic position there's not much in the way of paiud geology positions in the UK. Oz offers so many of them at at least triple UK wages, so I can walk into a job, live c heaply, earn lots of money and then in 5 or os years come back to the UK with a nice little nest egg and hopefully enough money to fund a PhD. It's a shame really as there are so many young geoscientists that are part of my graduation year that were set to do a PhD or a Masters and when the government cut the NERC funding it ruined their plans. 

Leah 

Just dragged out 'Volcanoes' By Dr Peter Francis.  I read it about 30 years ago. (ISBN 0 14 02 1897 cost £2.95).  He doesn't mention Toba or supervolcanoes.  I think that is a comparatively recent term.

This really has got me wondering.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

Humanities suffer even more so from funding cuts.  It's a real shame that education doesn't seem to be as important as it should be.

Sorry to have started the debate, John.  Not really sure how this will now be resolved lol

I'm not entirely sure all this isn't just semantics. 

My surrogate bible Wikipedia states:

"The Toba supereruption (Youngest Toba Tuff or simply YTT[1]) was a supervolcanic eruption that occurred some time between 69,000 and 77,000 years ago at Lake Toba (Sumatra, Indonesia)".

So where is everyone coming down on this issue then?  Was Toba a supervolcano or not?  And would this make it any more or less likely that Yellowstone will erupt in our lifetime?

I am going to try and get hold of Steve Sparks on this one.  He is Professor of Geology at Bristol Uni, and a vulcanologist.

I first met him 15,000' up in the Andies when he was doing his PhD. 

Nice guy. 

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

It was a super eruption, but not sure about the volcanoe, although there were at least two supererruptions at the Toba site. 

Yellowstone may or may not blow in our life time, but one thing to remember is the frequency of erruptions is on a 60ky scale, and we're overdue this by about 30ky. Although of course one could say that the Zircon dating is massively out and the geochemists don't know what they're talkign about. but there has been more activity at the site in recent years inclusing movement along dyke swarms and massive amounts of uplift in the upper magma chamber. If we get a "pop" from that it won't be too bad, it's if the lower magma chamber blows we should worry! 

Leah 

No sitting on the fence for me, I'm going with Supervolcano. I don't think whether Toba was one or the other, would make it any more or less likely that Yellowstone will erupt at any given time. (Although I may be wrong on that). As Leah suggests that's simply a function of periodicity, although with the timescales involved the margin of error could be well in excess of any of our lifetimes!

OK, thanks for the input guys.  All very interesting and a great debate too.

And John, what a great way to meet someone! lol

I couldn't get into the earth science site of Bristol Uni, but last evening I went to Bath Geological Society meeting and the speaker was Dr Chris Woods, visiting professor of Bournmouth University.   He was speaking on World Heritage Volcanoes.

I took an opportunity afterwards to ask him about this.  He told me that the term 'supervolcano' is a media generated word, not a geology generated one, and didn't feel that it was something which should be readily used in geological circles.  Apparently it was Steve Sparks who developed the VEI (Volcanic Explosive Index) and what are termed 'supervolcanoes' fall into the highest catagory.

And now I eat humble pie.... Toba was considered to be one of the highest VEIs.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

Ah that's very interesting.  Technical terminology is very important, so it's better to know how to categorise the eruptions properly.  Though, if Yellowstone did erupt anytime soon, I doubt anyone would actually be quibbling about what to call it

Probably be catagorised as 'Bloody Big!'

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

lol and it's bound to be a complete shock to everyone too!

Everything comes as a shock to some people. 

Have you ever waited behind someone at traffic lights and suddenly they turn green........it really takes them by surprise!

 There has been plenty of publicity about Yellowstone, but I don't think the general public can appreciate the immense power of even a small volcano.   Because most only see it 'on the telly' they tend to be totally detatched and view it in the same way as a PC game.

 I saw a clip from one of these disaster films some years ago (it was probably called 'Volcano' to ensure the viewing public knew what it was about) and a 4x4 drove across a lava flow.  Yes, you guessed it, the tyres were still intact on the other side....and certainly no blistered paintwork!!!!!!!

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant