Quake update: Geologists of Jackson Hole: 'Just be prudent'
JACKSON, WYOMING JANUARY 16TH, 2009
An earthquake was felt at 9:15 pm on Thursday, January 15th in Jackson, Alpine, Etna and Thayne, Wyoming, and Idaho Falls, Idaho. According to the US Geological Survey, it was a magnitude 4.0 event located just north of Alpine Junction at a depth of 3 miles.
This earthquake occurred at the south end of the extended Teton Fault zone along the eastern base of the Teton Mountain Range. Geologists call this area the “Seismic Gap” because of the lack of recorded earthquakes—a linear area along the large Teton Fault, which is unusually seismically quiet. The recent swarm of hundreds of earthquakes in Yellowstone National Park lie near the northern end of this “seismic gap”.
This seemingly quiet seismic zone centered along the Teton Fault has been the site of magnitude 7. plus earthquakes in pre-historic times. The Faults have created the Grand Teton Mountains and shaped western Wyoming. Another magnitude 7. plus earthquake will fill this gap sometime within the next several hundred years. Some earthquakes are preceded by a perceptible increase in seismicity at one or both ends of the “seismic gap”. There is currently no reliable way to know in advance which small earthquakes are foreshocks to large earthquakes. There is no scientific basis to predict that a large earthquake is imminent.
...There is no reason to be overly concerned at this time. Just be prudent.