Update, 7:45 a.m. Thursday: The MyShake test alert you might have received on Thursday morning at 3:19 a.m. was a mixup between time zones in the test alert system, according to USGS. The real test alert is still scheduled for 10:19 a.m. Thursday.
Update, 12:00 p.m. Wednesday: The emergency alert you might have received on Wednesday morning at 9:30 a.m. was for a real 4.2 magnitude earthquake just east of the Bay Area city of Antioch, near Isleton in Sacramento County. The MyShake emergency alert test detailed below is unrelated and should still go ahead as scheduled on Thursday morning.
Wednesday morning’s earthquake was initially overestimated as having a 5.7 magnitude by ShakeAlert USGS, which triggered the WEAS emergency alert on our cellphones. Ultimately, the earthquake’s magnitude was downgraded to 4.2.
“Our goal is public safety. And so yes, there are going to be events that will be overestimated because every earthquake is a little different,” said Robert-Michael de Groot, coordinator at ShakeAlert Earthquake Early Warning System, USGS. “The most important point about the earthquake early warning system is public safety. We try to maximize public safety.”
De Groot said the fact that MyShake overestimated the magnitude of this quake is “the system doing what it does normally.”
Original story: Do you have the MyShake earthquake warning app downloaded on your cellphone?
Over 2 million Californians already do — and they’ll be getting a loud earthquake test alert on Thursday morning, as part of the Annual Great ShakeOut quake preparedness drill that takes place across the globe.
This alert is coming on the heels of a test of the FEMA emergency alert system that was sent to phones nationwide. Keep reading for what you need to know about this latest test alert — and more ways to get these earthquake warnings for real.
When will the MyShake earthquake test alert happen?
The MyShake app will be sending the test alert on Thursday, Oct. 19 at 10:19 a.m. PST.
Unlike that FEMA test alert that almost everyone experienced earlier this month, this phone alert will only apply to people with the MyShake app living in California, Oregon and Washington.
What will the alert look and sound like?
The MyShake test alert will be in the form of an image that will tell people to “Drop, Cover, and Hold On.” You’ll also get an audio alert that will signify that this is a test.
The MyShake app, developed by UC Berkeley seismologists and engineers as an early earthquake warning system, gets its quake data from the U.S. Geological Services (USGS) ShakeAlert system. The app processes that data, and then distributes the alerts to where they need to go, according to de Groot, the ShakeAlert coordinator.
“The USGS role is critical in terms of how MyShake operates,” de Groot said.
How can I get the MyShake app if I don’t already have it?
If you have an iPhone, you can download the MyShake app from the Apple app store.
If you have an Android phone, you can download MyShake from the Google Play store — but Android phones will also get these alerts automatically through the Android operating system (more on this below.)
Read more about the evolution of the MyShake app.
How will this system be used when a real earthquake is detected?
When an earthquake happens, multiple earthquake stations will detect the shaking of the ground. Algorithms then estimate the earthquake’s location and expected magnitude.
“If the earthquake is estimated to be magnitude 4.5 or greater, MyShake delivers an alert to phones in areas where shaking is predicted,” said Christina Valens, a data analyst at UC Berkeley Seismological Laboratory.
If someone is far enough from the earthquake’s epicenter, they will receive the alert a few seconds before the ground shaking gets more intense. These seconds of warning can be used to take protective action such as Drop, Cover, and Hold On, she said.
