October 2009
The Hebgen Lake fault after the magnitude 7.5
Hebgen Lake, Montana earthquake.
Yellowstone Seismic & GPS Monitoring Summary
Monday, November 2, 2009 03:21 PM MST
(Monday, November 2, 2009 22:21 UTC)
Current Volcanic-Alert Level: NORMAL
Current Aviation Color Code: GREEN
Seismicity Summary: During the month of October 2009, 218 earthquakes were located in the Yellowstone National Park region. The largest event was a magnitude 2.5 on October 15 at 3:39 PM MDT, located about 7 miles south southeast of West Thumb, Yellowstone NP. This event was the largest event in a swarm of 138 earthquakes that occurred October 12-23, with magnitudes ranging from -0.2 to 2.5.
Earthquake activity in the Yellowstone region is at relatively normal background levels.
Ground Deformation Summary: Continuous GPS data show that uplift of the Yellowstone Caldera has stopped for now. The WLWY station, located in the northeastern part of the caldera, underwent a total of ~23 cm of uplift between mid-2004 and mid-2009. Its record can be found here.
The general uplift and subsidence of the Yellowstone caldera is of scientific importance and will continue to be monitored closely by YVO staff.
An article on the current uplift episode at Yellowstone and discussion of long-term ground deformation at Yellowstone and elsewhere can be found at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php
This information is taken from the Yellowstone Monthly Activity Update at the Yellowstone Volcano Observatory (YVO) Website.
Current seismic activity in Yellowstone can also be found on the University of Utah Seismograph Stations (UUSS) website at:
http://www.seis.utah.edu/req2webdir/recenteqs/Maps/Yellowstone.html
