YELLOWSTONE NATIONAL PARK, Wyo. The rolling pine forests, snowcapped mountains and crisp fall evenings here tend to make people forget the fact that the park sits atop a huge simmering underground volcano. But new geologic events have served up reminders.
In a few days in July, acidic ground water dissolved parts of the unpaved trails in the Norris Geyser Basin, and the ground temperature of the trails shot up to 200 degrees from the usual maximum of 80. Park officials closed nearly half of the basin's trails, and they remain shut.
On Aug. 21, a magnitude 4.4 earthquake shook the southern boundary of the park and startled residents. Yellowstone is one of the most seismically active places on the planet, with hundreds of shakes and shimmers throughout the year. They reach magnitude 4 usually only every other year.
In the park, such events are no great surprise. "Change is what we expect in Yellowstone," said the park geologist, Hank Heasler.
Although there is no indication that any of the changes suggest an impending eruption, even that would not be so surprising.
http://www.nytimes.com/2003/10/07/science/07GEYS.html?ex=1066541288&ei=1&en=6bfbb4f20999c1a1
In a few days in July, acidic ground water dissolved parts of the unpaved trails in the Norris Geyser Basin, and the ground temperature of the trails shot up to 200 degrees from the usual maximum of 80. Park officials closed nearly half of the basin's trails, and they remain shut.
On Aug. 21, a magnitude 4.4 earthquake shook the southern boundary of the park and startled residents. Yellowstone is one of the most seismically active places on the planet, with hundreds of shakes and shimmers throughout the year. They reach magnitude 4 usually only every other year.
In the park, such events are no great surprise. "Change is what we expect in Yellowstone," said the park geologist, Hank Heasler.
Although there is no indication that any of the changes suggest an impending eruption, even that would not be so surprising.
http://www.nytimes.com/2003/10/07/science/07GEYS.html?ex=1066541288&ei=1&en=6bfbb4f20999c1a1