Re: Update on Yellowstone Earthquakes

Update on Yellowstone Earthquakes
Date: January 21, 2010
Contact: Jamie Farrell, Univ of Utah, 801-581-7856

Press Release
University of Utah Seismograph Stations

Released: January 21, 2010 2PM MST

This release is a continuation of information updates building upon our two 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 pair of earthquakes of magnitude 3.7 and 3.8 occurred in the evening of January 20, 2010 in Yellowstone National Park.

The first event of magnitude 3.7 occurred at 11:01 PM and was shortly followed by a magnitude 3.8 event at 11:16 PM. Both shocks were located around 9 miles to the southeast of West Yellowstone, MT and about 10 miles to the northwest of Old Faithful, WY. Both events were felt throughout the park and in surrounding communities in Wyoming, Montana, and Idaho.

These two 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 12 PM, January 21, 2010, was a magnitude 3.8.

There have been 901 located earthquakes in the swarm of magnitude 0.5 to 3.8. This includes 8 events of magnitude larger than 3, with 68 events of magnitude 2 to 3, and 825 events of magnitude less than 2.

There have been multiple personal reports of ground shaking from observations 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.

The swarm earthquakes are likely the result of slip on pre-existing faults rather than 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/

Series Of Minor Earthquakes Continue In Yellowstone

A series of micro to moderate earthquakes continue to shake some visitors and residents in and near Yellowstone National Park. The activity is centered in the northwest corner of the Yellowstone Caldera, in the backcountry roughly half-way between Old Faithful and the community of West Yellowstone, Montana. As of 9:00 a.m. MST Friday, January 22, 1,033 earthquakes had been recorded since the swarm began occurring on Sunday afternoon, January 17.

Ten of the earthquakes have been magnitude 3.0 or greater, with a 3.8 magnitude earthquake recorded late Wednesday evening. The larger quakes have been felt by people in Old Faithful, West Yellowstone, Canyon, Mammoth Hot Springs, Grant Village, Madison, and Gardiner. No damage or injuries have been reported. Scientists are confident that the current earthquake activity is due to the shifting and changing pressures in the earth’s crust, and not to any change or increase in volcanic activity in Yellowstone.

The park is using this occasion to reinforce earthquake preparedness, and to remind both employees and visitors how the unique and active geologic nature of the park has resulted in the creation of the world’s largest collection of geysers, hot springs, and other hydrothermal features. Yellowstone averages about 1,600 earthquakes a year, and recorded 1,652 earthquakes in 2009. The park has experienced 80 earthquake swarms in the last 15 years. The last swarm of 133 very small earthquakes occurred in mid October 2009 near Heart Lake, in the south-central portion of the park.

This earthquake activity is being monitored ’round-the-clock by staff of the Yellowstone Volcano Observatory, a cooperative effort of the National Park Service, the U.S. Geological Survey, and the University of Utah. Generally, earthquakes less than a magnitude 3.0 are not felt by people. It typically takes an earthquake of magnitude 4.0 or greater to cause structural damage, and a magnitude 6.5 earthquake to cause the surface of the ground to rupture.

A continually updated map and list of earthquakes in Yellowstone is available online at http://www.seis.utah.edu/req2webdir/recenteqs/Maps/Yellowstone.html. More information on the Yellowstone volcano and the park’s geothermal systems can be found on the Greater Yellowstone Science Learning Center web site http://www.greateryellowstonescience.org.

The earthquake swarm on the northwest edge of Yellowstone Caldera that began on January 17, 2010 continues. There is still no indication of premonitory volcanic or hydrothermal activity.

PRESS RELEASE FROM YVO PARTNER UNIVERSITY OF UTAH SEISMOGRAPH STATIONS
Released: January 25, 2010 12PM MST

This release is a continuation of information updates building upon our three 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 pair of earthquakes of magnitude 3.0 and 3.1 occurred in the evening of January 24, 2010 in Yellowstone National Park. The first event of magnitude 3.0 occurred at 11:09 PM and was followed by a magnitude 3.1 event at 11:21 PM. Both shocks were located around 9 miles to the southeast of West Yellowstone, MT and about 10 miles to the northwest of Old Faithful, WY. Typically, events of this magnitude are felt in and around the Park, but there were no reports of these particular events being felt.

These two 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 9 AM MST, January 25, 2010, has been a magnitude 3.8. There have been 1,271 located earthquakes in the swarm of magnitude 0.5 to 3.8. This includes 11 events of magnitude larger than 3, with 97 events of magnitude 2 to 3, and 1,163 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.

The swarm events are likely the result of slip on pre-existing faults and are called tectonic earthquakes 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/

Earthquake Update for January 28
Date: January 28, 2010
Contact: Al Nash, 307-344-2015


Press Release
University of Utah Seismograph Stations
Released: January 28, 2010 9:00AM MST

This release is a continuation of information updates building upon our four 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 pair of earthquakes of magnitude 3.1 and 3.2 occurred in Yellowstone National Park. The magnitude 3.1 event occurred at 12:52 PM on January 27, 2010. The magnitude 3.2 occurred on the morning of January 28, 2010 at 1:46 AM. Both shocks were located around 9 miles to the southeast of West Yellowstone, MT and about 10 miles to the northwest of Old Faithful, WY. Both earthquakes were reported felt in Yellowstone National Park.

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 9 AM MST, January 28, 2010, has been a magnitude 3.8.

There have been 1,497 located earthquakes in the swarm of magnitude 0.4 to 3.8 up to 9AM January 28, 2010. This includes 12 events of magnitude larger than 3, with 111 events of magnitude 2 to 3, and 1,374 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/