ShakeAlert earthquake warning system now uses GPS data to determine magnitude

SAN FRANCISCO (KGO) -- New developments that just might make a difference for you in the next major earthquake. On Wednesday, the U.S. Geological Survey announced a major improvement to the ShakeAlert system -- all because of data gathered by satellites.

Right now, you'll get an alert on your phone when there's an earthquake nearby of magnitude 4.5 or larger.

Now, satellite data has been incorporated into the warning system.

So, if there's a very large earthquake, people will find out how big is and where it's centered much sooner.

Scientists say, that will give us more time to take action.

Major earthquakes could mean major damage.

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"The magnitude 7 earthquakes are the ones that typically cause the damage," said Bob de Groot with USGS.

So early warning could be key to protecting people and infrastructure.

The ShakeAlert earthquake early warning system sends alerts to users in California, Oregon, and Washington via a phone app.

Those warnings - usually just a few seconds - depend on how far you are from the epicenter of the quake.

De Groot is a lead shake alert operations team member.

"We've now integrated global positioning system data into our overall data feed into how we collect information about earthquakes," said de Groot. "GPS sensors will allow more accurate determination of the increasing magnitude."

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By incorporating data from GPS systems and using data from 1,500 seismic sensors, scientists will be able to give people more opportunity to protect themselves - to drop, cover, and hold on.

Here's how it works.

"The GPS sensors measure how far the earth has moved up, down, sideways and left to right. The seismic sensors tell us how fast the ground is moving," said de Groot.

"I think it's very exciting because it's bringing in a whole new kind of observation that we didn't have in the system before 403, and improving its functionality for the very large earthquake that we will eventually encounter," said Jessic Murray, a geophysicist with USGS.

The improvements to the shake alert system are welcomed by San Francisco Department of Emergency. It released this statement:

"We are encouraged by recent developments in earthquake warning technology and look forward to continuing our work with USGS to ensure San Franciscans receive the earliest warnings possible. We encourage everyone to take steps today to prepare for the next damaging earthquake."

USGS says the system is more than 90% complete. Another 500 seismic sensors need to be added by the end of 2025.