Shake Alert uses new technology to make earthquake warnings more accurate

SACRAMENTO — A new technology is being introduced that could give people more time to get to safety during a strong earthquake.

The My Shake app can send a shaking alert before a strong quake begins, and the data underlying these alerts is now much more accurate.

When an earthquake hits California, the app is designed to send out an immediate alert, giving people several seconds to get to safety before the powerful seismic waves arrive.

Robert de Groot of the US Geological Survey said the Shake Alert system has been active since 2019.

“We know this tool works and has a lot of potential for everyone in California,” he said.

The Shake Alert system previously relied on a network of ground-based seismometers, but now also uses GPS sensors. These can measure the strength of the earthquake from space satellites.

“Instead of measuring how fast the ground is moving, like seismometers do, we now measure how far it is moving up, down and sideways,” de Groot said. “And that potentially means we can warn people faster.”

De Groot said the new data could help more accurately determine the magnitude of larger earthquakes, such as the Loma Prieta quake that struck San Francisco in 1989.

“We need this additional information to be able to assess the magnitude of the earthquake more accurately and possibly more quickly,” he said.

The early warning also leaves enough time to automatically stop trains, open fire station doors and close pipelines – measures that can save lives.

“The farther away you are, the more warning time you have,” said de Groot. “Even a few seconds count.”

The Shake Alert system also covers Oregon and Washington state.