Volcano Update from Archive

Wednesday, February 3, 2010 11:22 AM MST (Wednesday, February 3, 2010 1822 UTC)

Yellowstone Volcano
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

An earthquake swarm continues on the northwest edge of Yellowstone Caldera. There is still no indication of premonitory volcanic or hydrothermal activity. As such, the Volcanic Alert Level remains at Normal (Aviation Color Code of Green).

A daily update about the swarm can be found at: http://volcanoes.usgs.gov/yvo/publications/2010/10swarm.php.


Press Release

University of Utah Seismograph Stations

Released: February 03, 2010 10AM MST

This release is a continuation of information updates building upon our five previous press releases on the ongoing earthquake swarm on the west side of Yellowstone National Park.

The University of Utah Seismograph Stations reports that a period of increased seismic activity occurred on February 2, 2010 beginning at ~3:30 PM MST. This period of increased activity lasted about 6 hours and included at least 2 events that were reported felt in Yellowstone National Park. The two largest earthquakes during this sequence were magnitude 3.1 and 2.8 that occurred at 7:31 PM and 7:44 PM respectively.

These earthquakes are part of an ongoing swarm in Yellowstone National Park that began January 17, 2010 (1:00 PM MST). The largest earthquake in the swarm as of 7 AM MST, February 03, 2010, has been a magnitude 3.8. There have been 1,719 located earthquakes in the swarm of magnitude 0.3 to 3.8. This includes 14 events of magnitude larger than 3, with 135 events of magnitude 2 to 3, and 1,570 events of magnitude less than 2. There have been multiple personal reports of ground shaking from observers inside the Park and in surrounding areas for some of the larger events (for felt reports, please visit http://earthquake.usgs.gov/eqcenter/dyfi/). Earthquake swarms are relatively common in Yellowstone.

Yellowstone Volcano Observatory scientists still consider that the swarm events are likely the result of slip on pre-existing faults and are not thought to be caused by underground movement of magma. Currently there is no indication of premonitory volcanic or hydrothermal activity, but ongoing observations and analyses will continue to evaluate these different sources.

Seismic information on the earthquake can be viewed at the University of Utah Seismograph Stations: http://www.seis.utah.edu/.

Seismograph recordings from stations of the Yellowstone seismograph network can be viewed online at: http://quake.utah.edu/helicorder/yell_webi.htm.

Anyone who has felt earthquakes in the swarm are encouraged to fill out a form on the USGS Community Felt reports web site: http://earthquake.usgs.gov/eqcenter/dyfi/.

This press release was prepared by the Yellowstone Volcano Observatory partners of the U.S. Geol. Survey, the University of Utah, and the National Park Service: http://volcanoes.usgs.gov/yvo/


The Yellowstone Volcano Observatory (YVO) is a partnership of the U.S. Geological Survey (USGS), Yellowstone National Park, and University of Utah to strengthen the long-term monitoring of volcanic and earthquake unrest in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

Jacob Lowenstern, USGS

Scientist-in-Charge, Yellowstone Volcano Observatory


Robert Smith, University of Utah

Coordinating Scientist, YVO

Henry Heasler, Yellowstone National Park

Coordinating Scientist, YVO