Big earthquakes raise interest in West Coast warning system

The powerful Mojave Desert earthquakes that rocked California ended a years-long lull in major seismic activity and raised new interest in an early warning system being developed for the West Coast. The ShakeAlert system is substantially built in California and overall is about 55% complete, with much of the remaining installation of seismic sensor stations to be done in the Pacific Northwest, said Robert de Groot of the U.S. Geological Survey. Areas that have the appropriate number of sensors include Southern California, San Francisco Bay Area and the Seattle-Tacoma region, de Groot said.