Geophysical Studies Reveal Potential Quake Hazard in Spokane Area
The US Geological Survey says there is a potential earthquake hazard in the Spokane area.
SPOKANE, WA - The US Geological Survey says there is a potential earthquake hazard in the Spokane area.
Preliminary interpretations of a recent geophysical survey confirm the presence of earthquake faults as well as reveal the possibility of previously unknown faults beneath the greater Spokane area.
During the spring of 2013, the U.S. Geological Survey undertook an airborne magnetic survey over the Spokane area to help understand the geologic reasons for a series of earthquakes and ground uplift that occurred several years earlier.
A sequence of 105 small (less than magnitude 4) earthquakes occurred beneath Spokane in 2001, accompanied by a small increase (1/2 inch) in ground elevation. The shape of the deforming ground surface was consistent with movement on a northeast-trending fault beneath Spokane, yet no known mapped faults in Spokane have been active in the last 1.6 million years.
To find the Spokane fault that caused 105 earthquakes in 2001, and evaluate its potential for large earthquakes in the future, scientists turned to geophysical tools to "see" below the surface.
"As the director of Spokane Emergency Management, we work diligently on preparing our community for disasters which includes identifying hazards in our area. The USGS has performed studies and their preliminary findings will help us develop effective mitigation strategies," said Spokane County Sheriff Ozzie Knezovich.