No one can predict when, where, and how big the next earthquake might be, but earthquake-prone places like California and Japan have installed systems that can warn of ground-shaking a few seconds in advance. These systems, known as “earthquake early warning systems,” exploit the different waves produced by earthquakes.
“So, when an earthquake happens, it generates all different kinds of waves,” said Dr. Keith Koper, a professor at the University of Utah and the director of The U’s seismograph stations.
“The P waves come out first, and the P waves are small, and they're fast. They don't cause a lot of the damage. But it turns out, we can use them to detect and know that an earthquake just happened very, very quickly. And the waves that do cause a lot of damage are called S for secondary waves. And the secondary waves are relatively slow. The whole sort-of point is, if we can detect the P waves first and say, ‘Oh my gosh, we think it's a big earthquake,’ we can send that information out as an alert faster than the S waves can arrive,” Koper said.
Utah does not have an earthquake early warning system yet, but if one was installed, citizens could get anywhere between a few seconds to one minute of advance notice of ground shaking. Although it doesn’t sound like much, a few seconds would be enough time to get under a desk, and for systems to automatically shut off gas or stop trains.
“In the U.S. the first earthquake early warning system is in the West Coast. The next tier of states that it's supposed to move to would be Nevada, Utah, possibly Alaska. We could get it as soon as five to six years. It would take what we call a state-federal partnership. And so, the state of Utah would have to be willing to invest in it, and they would only be willing if the public was behind it,” Koper said.