DisastersSunday tremor may accelerate deployment of West Coast early warning system

Researchers and individuals working with California’s ShakeAlert system received a 10-second warning before last Sunday’s earthquake struck the San FranciscoBay Area at 3.20 a.m. “Earthquake! Earthquake!” the warning system cautioned, followed by “Light shaking expected in three seconds.”

Mexico and Japan already have a public earthquake warning system, but a collaboration in California between the U.S. Geological Survey, California Institute of Technology, University of California Berkeley, and University of Washington is still in an experimental phase. The project needs about $80 million for equipment, software, and other seismic infrastructure upgrades to launch the warning system throughout the West Coast.

Early alert systems detect primary waves (P-waves) as they move through the Earth at almost twice the speed of the earthquakes’ destructive S-waves, which shake the ground. Seismic stations are placed throughout California to record the presence of P-waves. Warning systems further from the epicenter of a quake receive more advance warning.

Bay Area Newsreports that Governor Jerry Brown signed a state law last fall ordering the creation of an early warning system, but the project has so far received only $10 million, mostly from the private Gordon and Betty Moore Foundation. Supporters of ShakeAlert are hoping last Sunday’s magnitude-6 earthquake will create a new sense of urgency, forcing lawmakers to make funds available for the warning system.

Japan and Mexico built their warning systems only after devastating earthquakes, said Richard Allen, director of the UC Berkeley Seismological Laboratory. Today, residents in Japan can receive up to a minute’s notice before a quake strikes. “We want to learn from these other examples and not wait until thousands of Californians are killed before we build an early warning system,” Allen said.

Stressing the importance of a warning system, scientists claim that Sunday’s quake — the largest in the Bay Area since the magnitude-6.9 Loma Prieta quake in 1989 — might release more seismic activity after decades of calm. Earthquakes can transfer stress from one system to another, said John Rundle, a physics and geology professor at University of California Davis. “It’s a little bit concerning that this activity has started and appears to be resuming a more active trend,” Rundle said.

UC Berkeley is hosting a three-day international forum next week on earthquake early warning systems. A key session of the event will discuss how to persuade governments to fund projects like ShakeAlert in vulnerable regions. “If we have an earthquake this afternoon,” Allen said he tells lawmakers, “you will fund it next week.”