Yellowstone National Park has been rattled by more than 200 earthquakes in the past two days following a period of 11 months of quiet seismic activity in the park, according to the Denver Post.
The quakes have been gaining strength, with a 3.1 tremor recorded at 11:03 a.m. MST today (Jan. 18). A 2.9 quake was recorded at 12:38 p.m. MST.
Prof. Robert B. Smith, a geophysicist at the University of Utah and one of the leading experts on earthquake and volcanic activity at Yellowstone, said that the activity is a “notable swarm.”
“The swarm is located about 10 miles northwest of Old Faithful, Wyo., and nine miles southeast of West Yellowstone, Montana,” said Smith.
Jamie Farrell, a doctoral student in geophysics who works with Smith at the University of Utah, said that as of 1:15 p.m. today, approximately 230 quakes have been recorded in the past two days.
Farrell said the quakes are occurring in an area about 5 miles from where the largest swarm of quakes was ever recorded in October 1985.
Quakes in the current swarm have ranged in magnitude of 0.5 to 3.1.
Farrell said there have been reports of at least one of the tremors being felt in the park, but he is expecting more reports as the earthquakes continue.
Smith said such swarms are “relatively common.” Today’s tremors seem to be normal tectonic activity, and is not “not an indication” that some sort of volcanic activity will occur.
Since 1995 there have been 80 swarms, including the one that started Sunday, Farrell said.
In late December 2008 and early January 2009, Yellowstone National park experienced the second largest earthquake swarm in Yellowstone’s recorded seismic history. The swarm under the north end of Yellowstone Lake consisted of 813 earthquakes with magnitudes ranging up to 3.9.