Friday, January 2, 2009

Is Yellowstone about to blow its top?

Photo by Austin Post, courtesy of USGS

Scientists are puzzled by the recent spurt of seismic activity in Yellowstone. Swarms of tremors in the park are not that unusual, but the number and proximity of this event definitely is.

James Pethokoukis did a Splunk search and discovered that during the entire decade of the 80's there were 128 Yellowstone area tremors measuring 2.5 or greater on the Richter scale. There have been 30 in the past four days centered under and around Yellowstone Lake alone, some measuring as high as 3.8. The number of 2.5 or higher tremors in the Yellowstone Lake area for the entire decade of the 80's was 4. I did post a comment on the article asking the author why he did not include data from the 90's. I haven't got an answer to that one yet.

The AP reports: "Several hundred quakes centered under the northern end of Yellowstone Lake have now occurred since Dec. 26. No damage has been reported. Earthquake swarms happen fairly often in Yellowstone. But scientists say it's unusual for so many earthquakes to happen over several days. Yellowstone lies mostly in northwestern Wyoming and is the caldera of a volcano that last erupted 70,000 years ago. Scientists have not concluded what is causing the earthquakes."

From "Scientists wonder if the shaking might presage a larger event. This month's swarm is the most intense in this area for some years, scientists said. It is centered on the east side of the Yellowstone caldera, a giant basin created in a colossal eruption some 620,000 years ago. Researchers have long predicted that the Yellowstone supervolcano will eventually erupt again, with devastating consequences for much of the United States. Half the country could be covered in ash up to 3 feet (1 meter) deep, one study predicts. But those same researchers say nothing suggests such an eruption is imminent. They point out, however, that Yellowstone seems to blow its top about every 600,000 years."

The Yellowstone Volcano Observatory is a bit more conservative: "The December 2008 earthquake sequence is the most intense in this area for some years. No damage has been reported within Yellowstone National Park, nor would any be expected from earthquakes of this size. The swarm is in a region of historical earthquake activity and is close to areas of Yellowstone famous hydrothermal activity. Similar earthquake swarms have occurred in the past in Yellowstone without triggering steam explosions or volcanic activity. Nevertheless, there is some potential for hydrothermal explosions and earthquakes may continue or increase in magnitude. There is a much lower potential for related volcanic activity."

This story may not have stirred my interest so much had it not been for the 2005 BBC/Discovery Channel docudrama, "Supervolcano Caldera". Being in Colorado, I'm not close enough for a super-eruption to kill me instantly, but not far enough away to avoid eventually freezing to death, starving to death or at best, living the rest of my life in desperate squalor. Still, it might be better than living through the constant drip, drip, drip of ever increasing socialism.

This will likely turn out to be just a seismic oddity that will be of great interest to scientists in years to come. Still, for the rest of us, it's worth keeping an eye on for now.

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