The hidden volcano

Lots of news today about increased seismic activity on Mt. Saint Helens. Scientists are predicting a small-to-moderate eruption occurring within the next few days, perhaps spewing ash and rock up to three miles from the crater.

A much bigger volcano with potential to wreak orders of magnitude more damage is little known, though millions visit every year. The Yellowstone caldera has been erupting regularly every 600,000 years, and the last eruption was 640,000 years ago. By way of comparison, the next eruption will be something on the order of 2,500 times more powerful than the 1980 Mt. Saint Helens eruption.

I recently read a great book by Bill Bryson, A Short History of Nearly Everything. One of the chapters went into scary detail on what to expect if (more like when) it blows again.

A nice summary of what the Yellowstone caldera is about, where it came from and what it's capable of is available if you aren't up for reading Bryson's book.