January 2, 2009

A Supervolcano for 2009?

According to a blog post in 60-Second Science, there has been some ominous rumbling going on in the Yellowstone caldera for the last 6 days.
Any disaster fiend will tell you that Yellowstone National Park is long overdue for a monster eruption that could leave as much as half the U.S. under a blanket of ash. And there are rumblings the big one could be imminent in the wake of a series of 30-plus mini-earthquakes in the park over the past few days—too weak to be felt by humans for the most part but picked up by the seismometers at the University of Utah.

After all, the geologic record shows that the giant caldera we affectionately call Yellowstone has blown every 600,000 years or so over the past 2 million years. The last big eruption? About 640,000 years ago when the park spit out about 240 cubic miles worth of rock, dirt, magma and other stuff.
The post mentions 30-plus earthquakes, but there have actually been almost 300 small quakes (and counting) so far, according to USGS. The tremors have been located very closely together at the northern end of the lake, which has been steadily rising for a couple of years, pushed up by a bulge of pressurized magma below. The tremors are also remarkably shallow, majority occurring 0.0–2.2 km underground.

As if a credit crisis and accelerating climate change wouldn't be enough, we could quite possibly be faced with a supervolcano eruption and a resulting centuries-long nuclear winter. Now where is that fourth rider...? But hey, at least global warming could be forgotten for a while and the seismographic images are pretty.

Yellowstone registers about 1000 quakes in a normal year, so this kind of swarming is only a bit out of the ordinary. Nothing serious is probably going to happen in another few thousand years, but whenever it happens—and it will—there is absolutely nothing we can do about it, so let's just enjoy the show.

When that eruption finally comes, it will be the media event of a few hundred thousand years. Oh, but there was no media to witness the last one, so I guess it'll be the biggest media event ever. That'll be a black swan event with some mighty consequences.

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