The agency has also spent another $1 million to buy sensors for the system after Congress approved a special increase of $5 million in the survey’s billion-dollar budget, the agency said in a news release.
The award will go to the University of California’s Seismological Laboratory, the California Institute of Technology, the University of Oregon and the University of Washington to expand their sensor networks and increase the number of users who will receive alerts as the network grows, the geological survey said.
But even this amount is far from the $38 million needed to complete the early-warning system for the three Western states, plus the $16 million a year needed to keep it running for the first five years, said Cecily Wolfe, coordinator of the geological survey’s earthquake hazards program in Reston, Va.
The three-state system has 624 quake-detecting seismometers in the network now, Wolfe said, and another 150 will be added this year. But 1,675 sensors will be needed before the network is complete.
Early-warning systems operate when arrays of seismometers detect an earthquake’s first fast-moving seismic waves, which are rarely felt strongly, and instantly transmit an alert to distant areas before a quake’s second slower-moving seismic waves arrive to cause the dangerous ground shaking that can destroy buildings and take lives.
Even before it is complete, California’s ShakeAlert early warning network worked well during the magnitude 6.0 South Napa earthquake last Aug. 24. It sent a five-second warning to Berkeley test users and a nine-second warning to San Francisco. Even those few seconds would be enough to warn people to “duck, cover and hold on,” as the quake mantra says.
BART officials were alerted by the incomplete ShakeAlert system during the Napa quake, but there was no need to stop the BART trains since no damage was likely beyond the Napa area, transit officials said at the time.
A magnitude 3.8 quake in Los Angeles last August also was detected, and an alert was issued within 3.3 seconds, according to officials at the geological survey headquarters in Pasadena, which monitors the progress of the ShakeAlert system for Southern California.
©2015 the San Francisco Chronicle. Distributed by Tribune Content Agency, LLC.