BERKELEY, Calif. - The MyShake app designed to give a short warning before a quake hits, sounded the alarm early Tuesday morning when an earthquake centered in Humboldt County hit.
It woke people up here in the Bay Area and beyond. And in some cases, it alerted people out of state.
The UC Berkeley seismologist who is behind the development of the app said it worked well. Richard Allen, director of the Berkeley Seismological Laboratory, said whether a user is alerted depends on the default setting on the app.
People from different parts of the Bay Area said they didn't feel the shaking but that they're grateful for the technology.
"Earthquake. Drop, cover and hold on," was audio that was part of the alert from the MyShake app that was sent to 270,000 users at 2:34 am Tuesday, according to Allen
"I didn't feel anything so it's no big deal to me. But then I looked and it was north," Joe Balboa said. He received an alert while he was at home in San Jose.
Seismologists said the notification went out to people as far north as Oregon and south to Santa Cruz. The alert time ranged from a few seconds up to a minute before the earthquake struck.
The further away from the epicenter, the longer the lead time.
"I never felt it, but it did warn us," Dave Halliday of Alameda."Living in California my whole life, it's nice to know ahead of time. Anything comes up, It can help."
"There were a lot of people who got the alert in the Bay Area who didn't feel anything. That's because the shaking intensity was lighter for this earthquake than typically for a magnitude 6.4 earthquake," Allen said.
He received word that someone in San Diego and as far away as Virginia received the alert. But he said the app worked the way it should.
It automatically alerted users based on their current location. But if the app's default setting is set to the person's home base, it will alert that user no matter where that person is.
"If you have a home base set in the Bay Area, it doesn't matter where in the world you were today, you would have received that alert," said Allen
Some people complained on social media about being woken up by the app even though they didn't feel the earthquake.
Allen said there is no way the app can only alert those who will feel the shaking.
Amber Lee is a reporter with KTVU. Email Amber at Amber.Lee@Fox.com or text/leave message at 510-599-3922. Follow her on Facebook @AmberKTVU, Instagram @AmberKTVU or Twitter @AmberKTVU