Thursday, February 4, 2010

Quakes continue to rumble Yellowstone

A swarm of mostly imperceptible earthquakes continues to shake Yellowstone National Park in what is now the park’s second-largest on record.

From the swarm’s beginnings on Jan. 17 through Monday morning, some 1,620 quakes were recorded by seismologists in the park, which sits atop a gigantic volcanic caldera. The activity is centered around the northwest corner of the Yellowstone caldera, in the back-country between West Yellowstone, Mont., and Old Faithful.

The vast majority of the quakes have been too small to be felt. The highest quake has been a magnitude 3.8, and no injuries or damage have been reported. It typically takes above a magnitude 5 to cause damage.

The swarm follows a high-profile cluster just over a year ago which brought around 900 quakes around the northern part of Yellowstone Lake.

While the number of earthquakes is larger this time around, thus far, the swarm of media interest and online speculation has not been as high.

“I think that we’ve done a better job, really in the past year, sharing with people that earthquake swarms are not that unusual,” said Al Nash, park spokesman, last week.

The swarm is the 80th in the last 15 years.

Last year, a man created a YouTube video urging everyone within a 200-mile radius of the caldera (which would include Powell) to evacuate. It helped fuel online speculation about a pending volcanic eruption, and was even picked up as a legitimate warning by a Dutch radio network.

Yellowstone did suffer a cataclysmic eruption in 2009 — but only in the Hollywood disaster flick “2012,” which was actually filmed in British Columbia. The real Yellowstone Park remains unharmed.

“Perhaps some people chose to make a lot out of something that didn’t happen,” said Nash.

The current swarm received a significant bump in national attention on Sunday when the New York Times wrote about the quakes and a popular news aggregator, the Drudge Report, linked to an earlier Associated Press story about the underground activity.

On Monday, there were plenty of individuals online engaged in fearful speculation.

“Yellowstone could be about to blow. Maybe these are warning quakes,” wrote one Arizona man on Twitter. “I wouldn’t stay around there, even if this has happened before.”

The Yellowstone caldera is monitored by the Yellowstone Volcano Observatory, a partnership of scientists from the U.S. Geological Survey, the National Park Service and the University of Utah. The group has said it is “confident” that the recent quakes are the result of shifting and changing pressures in the earth’s crust — not due to an increase in volcanic activity.

Earthquakes generally have to be a 3 or higher on the Richter scale to be felt; only 13 of the recent events have been larger than a 3.

In 1985, which had the largest swarm on record, the park was shook by more than 3,000 quakes, with the largest registering a 4.9.

This time around, the two largest events — a 3.7 and a 3.8 — occurred on the night of Jan. 20.

The larger earthquakes have reportedly been felt as far off as Island Park, Idaho, and Gardiner, Mont., but not by all in those areas.

As Nash puts it, “some of the people have felt some of the earthquakes.”

Nash, who lives and works in Mammoth Hot Springs, and Glenn Koelling, currently working as a winter keeper at Canyon Village, are among those who have not noticed the shaking.

In an e-mail, Koelling, of Powell, said her experience with the swarm “has been rather boring.”

“The quakes were so far south that we didn’t feel any of them here,” wrote Koelling last week. “I live with two guys and no one here is concerned about the swarm.”

“Also,” Koelling added, “we’re not worried about Yellowstone blowing up. Not even a little bit.”

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