This App Warns You An Earthquake Is Coming Before It Strikes The Big One is coming. ShakeAlert, an earthquake early alert warning system from the U.S. Geological Survey, may save lives when it does.

For those living on the West Coast of the U.S., earthquakes are an ever-present danger.

Although The Big One hasn't hit a major metropolitan area since 1994, all it takes is a magnitude 6 plus to rattle nerves, take lives, and cause significant damage.

To help citizens get out of harm's way should a major earthquake hit, the U.S. Geological Survey (USGS), along with a coalition of State and university partners, has created a new system called ShakeAlert, which warns people an earthquake is coming before the shaking arrives.

The system sends alerts to your smartphone, depending on where you happen to be when the earthquake strikes.

ShakeAlert only works for those living on the West Coast, but hopefully, other at-risk locations will adopt the technology.

Earthquake threats

There's a reason ShakeAlert focuses exclusively on the West Coast. Most of the nation's earthquake risk is concentrated in that area.

Federal Emergency Management Agency (FEMA) estimates the average yearly loss from earthquakes nationwide to be $6.1 billion, with 73% ($4.5 billion) coming from Washington, Oregon, and California.

UCGS predicts that in the next 30 years, California has a 99.7% chance of a magnitude 6.7 or larger earthquake, and the Pacific Northwest has a 10% chance of a magnitude 8 to 9 earthquake on the Cascadia subduction zone, a megathrust fault that extends from Canada to California.

How ShakeAlert works

Technology now exists that enables scientists to detect earthquake activity a few seconds after it begins.

During an earthquake, the rupturing fault first sends out P-wave energy, which rarely causes any damage. Sensors detect P-waves and immediately send the data to a processing center, where the location, size, and magnitude of the quake are determined. If the quake is big enough, a ShakeAlert message is relayed on the app and pops up on your phone.

If you have an Android, you don't even need to download the app. Earthquake warnings pop up automatically on your phone—as long as you enable location services and emergency notifications.

If you have an iPhone, then you need to download an app like MyShake or QuakeAlert.