California Rolls Out Earthquake Warning Program, But System Is Incomplete

Holly Quan
October 18, 2019 - 10:42 am
earthquake crack

SteveCollender/Getty Images


California took a big step toward earthquake safety on Thursday, the 30th anniversary of the 1989 Loma Prieta Earthquake, by rolling out for the first time statewide public access to ShakeAlert, its earthquake early warning system.

But while coordinators of the network want to eventually blanket the entire West Coast with earthquake detection sensors, at this point, the system isn't quite finished.

The plan is to have a total of 1,675 sensors across California, Oregon and Washington. Right now, 60% of California's sensor network is built out.

It's a slow process, given the need for permitting and overall logistics.

The system's seismometers detect motion in the ground, then send the information to one of three processing centers in the Bay Area, Southern California, or the Seattle area, according to the United States Geological Survey's Robert de Groot, a coordinator for ShakeAlert. 

It's important to make sure the sensors aren't placed in a spot that could send a false alarm, such as under a railroad trestle, he said. 

"There are some big quality control measures that are taken to make sure that those stations are in the right place, and we want to make sure they are separated from each other at an appropriate distance, so we can maximize the ability for these stations to pick up that earthquake," de Groot said. 

As the network of sensors continues to grow, the speed, reliability and use of early warnings will go up.

Alerts can give people a few seconds' head up before the shaking starts. But what seismologists and emergency officials are really excited about is the system's ability to communicate with automated systems.

"Where we're going to see a lot of effect is using the alerts to be able to do things that are automatic — slowing down trains, protecting water supplies, taking measures at the airport, getting surgeons to move the scalpel away — to stabilize a whole variety of systems," de Groot said. "That's where, once the event is over, the recovery will be easier because those systems would have taken some sort of protective action ahead of time."

The MyShake app for Apple and Android devices is available on Google Play and the App Store