April 8, 2004
Another Earthquake Hits Gros Ventre River Valley
At 9:54 a.m. on April 7, 2004, a magnitude 4.0 earthquake occurred in the Gros Ventre River Valley approximately 22 miles ENE of Jackson, Wyoming. This was the ninth earthquake recorded in the area in the past three months. The earthquakes have varied in magnitude from 2.9 to 5.0 on the Richter Scale. Eight of the earthquakes occurred during a six-hour period on January 7, 2004.
Earthquakes have occurred in this area before and are believed to be responsible for causing landslides such as the Gros Ventre slide, which created Lower Slide Lake. There are many existing landslides in the area, and it is possible that some of these landslides could be reactivated by future earthquakes. There has been no evidence of landslides occurring as a result of this recent activity, however.
The recent earthquakes are on the east side of Jackson Hole and are not associated with the Teton Fault, a complex capable of creating a 7.5-magnitude event. Little or no damage has been reported as a result from these events, nor have any injuries been reported.
For more information about this or other earthquakes in Wyoming, contact James C. Case at (307) 766-2286, ext. 225.
from the Office of the Wyoming State Geologist
Ron Surdam, State Geologist