Originally posted by Foxe
reply to post by TrueAmerican
Yes, in ancient times, if I recall, there was such a thing. Its called a mantle uplift if I recall. It basically turns a continent into one giant
Kilauea lava flow. Its non explosive I do not think, but its not common... if I recall, India and Russia have the remains of two...
It's long been a theory of mine that Yellowstone could just be the head of one coming up. Considering there's two other super volcanoes nearby
(nearby in geological terms) on the US continent (Long Valley, CA, and another one in the south west, forgot it's name) + dozens and dozens of
volcanoes... I've often wondered if they were not the head of a major uplift, slowly making its way up for millions and millions of years. Creating
hot spots as parts of it breaks loose.
As for Yellowstone, she isn't the biggest ever. The largest super volcano ever (forgot it's name) to blow that we know of, put out 5000 gigatons (5
mil megatons) of energy
[edit on 1-1-2009 by Foxe]
Just out of interest, you may be thinking of the Siberian Traps - this baby was a super-massive lava flow eruption covering an area of up to 7 million
squsre kilometers.
Now, I'm a bit rusty on the details, so anyone feel free to correct me, but it is believed that this inconcieveably large eruption (I believe the
phrase you were looking for is "mantle plume") was one of the great levellers in the history of our earth. Studies point to this taking place at the
boundary between the Permian and the Triassic eras, and it is thought that so much sulfur dioxide was released that the earth was plunged into a
worldwide ice age for hundreds of thousands of years. Ironically, at the same time, the amount of Carbon Dioxide realeased increased the global
temperature by up to 15 degrees Celcius, and the effects of this greenhouse warming could have lasted for millions of years afterwards. Current theory
suggest the ice age followed millennia of searing, desert conditions. It is believed that almost 99% of life was wiped out, and that we owe our
current existence to cyanobacteria which were able to survice in stagnant, otherwise lifeless water - what little there was. They produce CO2 as a
by-product and it is thought that over the millenia they produced enough to help the global temperature gradually rise back to levels where the ice
sheet covering the earth was able to melt.
We owe our existence to bacteria.
Oh, and to put things in perspective, the lava flow erupted for anywhere between
500,000 and 1 million years, give or take. And it is believed
that we have actually released more CO2 into the atmosphere in our hundred years' dalliance with petrochemicals than was released in the entire
mantle plume period.
Now THAT is some perspective.