super volcano question

They say they explode every 200,000 years. If this is true, then wouldn't that mean there shouldn't be very many species living on earth right now? The magnitude of a super volcanoe explosion is powerful enough to cause many lifeforms to become extinct. Because 200,000 years isn't enough time for evolution.

Humans, as we know them today are only 14,000-15,000 years old. That's either evolution or divine intervention. 200,000 years ... oh, we'd be amazed at what nature can do in that time ...

A super volcano eruption is devestating in the local area, and likely causes a bit of global cooling for a few years, but that's all. That said, the last super volcano eruption - Toba in Indonesia, about 74,000 years ago - does coincide with a 'genetic bottleneck' in humans, suggesting we nearly became extinct (maybe only a few thousands left at one point).

No major extinctions have coincided with super volcano eruptions.

Flood basalt eruptions - like the Deccan traps c65 million years ago and the Siberian traps c250 million years ago - are a different matter. But they last for millions of years and we've no worry on that score in the near future.

Originally posted by wildcat
They say they explode every 200,000 years. If this is true, then wouldn't that mean there shouldn't be very many species living on earth right now? The magnitude of a super volcanoe explosion is powerful enough to cause many lifeforms to become extinct. Because 200,000 years isn't enough time for evolution.

No, super eruptions are powerful, but nowhere near powerful enough to make a mass extinction event like the KT boundary. As Essan points out, they are devastating locally and apart from a bit of global cooling, not powerful enough to affect the world at large.

How it would affect the worlds economy though and as such how we would be affected by one now, would be an interesting question.

Unfortunately Wildfire, the answer to how a Super-Eruption would effect humans/planet cannot be 100% know until we actually experience one. I agree with most though, while effects would surely be devistating it shouldn't be close to a mass extinction, at least by itself.

This may be a more appropriate thread for my question:

This subject caught my eye and caused me to register and post. (Hi all by the way).

Have had an amateuristic interest in super volcano's and the link between super volcanic eruptions and subsequent global cooling. There is a mountain of strong evidence that links the two things together, I wont site that here because I am sure you are all aware of this already.

Over time though I have considered how often in Science we get these things backwards, upside down or inside out and have developed a theory that perhaps the same is true here.

Current thinking suggests that an eruption fills the atmosphere with particulate which blocks out sunlight and causes cooling - very plausible.

I also subscribe to the theory that natural cycles driving natural warming and cooling - not the activity of man or beast.

So, is it possible that the natural global cooling cycle which increases the weight of ice pack upon land mass, which cools the outer surface of the planet, disrupts the normal, non threatening behaviour of a super volcano (which is now no longer to expand and contract easily) resulting in a restricted building of pressure beneath the cooled and retracting crust until the point of an explosive eruption?

I liken this to putting a lid on a boiling saucepan. If the lid is loose, the gases (steam in this case) are released slowly and gently, it may boil over (like an small volcanic eruption) but no real harm is done. If however you add weight to that lid or reduce the space available for expansion, the pressure builds inside the pan and gases (again steam in this case) explode from the pan more violently (as with an explosive eruption).

I think that we have missed the pre-cursor here and confused the end result with the root cause. The root cause of the eruption (global cooling) then precipitates further cooling through atmospheric particulates and propagates a return to significantly colder conditions globally - perhaps even as far as an 'ice-age'.

I would appreciate ATS members pulling this apart to put my mind at ease!

Thanks all.

reply to post by BigfatDave


Welcome BigfatDave (and you are probably a skinny in-shape woman), I'm glad you signed up as you seem to know how to put some words together to form a thought. You'll fit right in here!

I'm not a geologist, but your theory sounds interesting and may get some discussion going. There is a massive thread here on the Yellowstone caldera. If you haven't seen it's worth a look if you have an interest in supervolcanoes. The thread is a monster, so it fits its topic well:

www.abovetopsecret.com...

I was going to answer but Essan has done it so correctly that i won't bother!



ELE? No.

Good idea to be living next to one when it goes off in "super eruption" mode? Again, no.

What is most surprising to me, historically speaking, is how few people are killed by volcanoes. Seriously, check it out. We all have this vision of this awesome power meaning mass deaths. The reality is, not so much.