Earthquake early warning system put to the test — and officials say it worked
SACRAMENTO — An earthquake warning system was put to the test this week when phones started sounding off across Northern California.
The ShakeAlert system rattled people awake around 2:30 a.m. Tuesday when seismometers sensed movement and triggered a warning ahead of a 6.4 earthquake.
"The part where you do the detection in the field to where it gets processed and where this Shake Alert message is produced, that happens in a few seconds, probably in the order of five seconds. That's pretty darn fast," said Robert de Groot, ShakeAlert operations coordinator with the U.S. Geological Survey.
But how much warning did people get after that? And was it successful? CBS13 went to the USGS to get answers.
"It's working the way it was intended to work. It's working exactly the way it should work," said de Groot.
He says some received the alert seconds before they started feeling the ground rumble while others got the warning and never felt anything at all. But considering its size, the quake had the potential to impact a widespread area and de Groot says a full-scale warning was critical.
"The goal is for you to hear that alert," said Bryan May, a spokesperson for the California Office of Emergency Services. "I got it at home at 2:30 in the morning and it woke me out of a sound sleep."
May says he's seen warnings 30 seconds ahead of the tremble or longer and that regardless of how many seconds you have, every second counts.
"Ten seconds is the average warning we talk about, but the further you are away from the epicenter, the longer that warning could be," May said.
"There may be some people who don't feel much shaking once they get their alert. Well, we're trying to balance. Our priority is human safety. We want to keep people safe," said de Groot.
Officials say you have to do more than just get the ShakeAlert app. You also have to have your notifications turned on so you get alerted even if you're not using the app. It's available to most devices and it's free.