June 2008
The Hebgen Lake fault after the magnitude 7.5
Hebgen Lake, Montana earthquake.
Yellowstone Seismic & GPS Monitoring Summary
Tuesday, July 1, 2008 12:10 MDT
Current Volcanic-Alert Level: NORMAL
Current Aviation Color Code: GREEN
Seismicity Summary: During the month of June 2008, 79 earthquakes were located in the Yellowstone region. The largest event was a magnitude 2.7 on June 4 at 9:02 PM MDT, located about 6 miles southwest of West Thumb, WY. There was a swarm of 27 events, June 4-8, with magnitudes 0.8 to 2.7, located about 6 miles southwest of West Yellowstone, MT.
Earthquake activity in the Yellowstone region is at relatively low background levels.
Ground Deformation Summary: Through June 2008, continuous GPS data show that most of the Yellowstone caldera continued moving upward, though at a lower rate than the past several years. The maximum measured ground uplift over the past 48 months is ~20 cm at the White Lake GPS station. An example can be found here.
The general uplift of the Yellowstone caldera is scientifically interesting 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/2007/upsanddowns.html
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
