Earthquake early-warning sensors being expanded to high-risk areas in California and Nevada

An infusion of federal funding will help expand or strengthen the U.S. Geological Survey’s earthquake early-warning system in California around Lake Tahoe, Death Valley, Mammoth and Bishop.

The University of Nevada, Reno, which runs the seismic network in eastern California, will use $1 million from the USGS to upgrade obsolete seismic sensors in Death Valley and the Mammoth and Bishop areas. The funding also will boost seismic networks in the Lake Tahoe and Truckee areas, where communications systems can be damaged in severe winters, said Graham Kent, director of the university’s Nevada Seismological Laboratory.

Eastern California and Nevada carry significant seismic risk. The Death Valley fault system, which stretches east of Bishop down to the southern reaches of Death Valley National Park, is capable of generating a quake of roughly magnitude 7.8, Kent said. The Las Vegas area would suffer damage if such a powerful quake occurred and the fault ruptured toward the southeast and toward the city, Kent said.

Las Vegas is particularly at risk because it sits on a former lake bed that amplifies shaking from an earthquake, much like how Mexico City suffered severe shaking in a 1985 earthquake.

A robust earthquake early-warning system in eastern California and Nevada could give residents of Las Vegas perhaps 30 seconds to 40 seconds of warning before strong shaking arrives, Kent said.

From a separate source of federal funds, the Nevada Seismological Laboratory is repairing outdated earthquake sensors in western Nevada with equipment that could be tied into the earthquake early-warning system if federal officials decide to expand the system into the Silver State, Kent said.

The Reno area has a seismic risk that approaches that of the San Francisco Bay Area; the Carson Valley just south of Reno is capable of producing a quake as large as magnitude 7.4; just east of Las Vegas is a fault that can produce an earthquake as large as magnitude 6.7.

The West Tahoe fault, located along Lake Tahoe’s western shore, is capable of producing an earthquake between magnitudes 7.1 and 7.4 and causing a tsunami of up to 30 feet high. The last massive temblor there was about 4,000 years ago.

About half of the 1,675 seismic sensors needed for a fully operational earthquake early-warning system for the West Coast have been installed; the networks in the Southern California and San Francisco Bay Area metro areas are largely built out.