ShakeAlert: 'just some time to know that a big earthquake is on its way'


A $3.6 million grant was awarded to scientists to advance an early earthquake warning system. Funded by the U.S. Geological Survey and the Gordon and Betty Moore Foundation, the ShakeAlert system is expected to warn people minutes before an earthquake hits.

When an earthquake happens two types of seismic waves are sent out, P-waves and S-waves.

P-waves are the primary waves. They are the first waves that reach the seismograph underneath the earth's surface. S-waves are the surface waves, which are followed by the P-waves and move over the surface. These are the one's that cause shaking on the surface and cause damage.

The ShakeAlert system has the ability to detect the P-waves, determine the location and time, and send a warning to people before the S-waves arrive, giving people the opportunity to duck and cover.

"That is what we want to give people, just some time to know that a big earthquake is on its way, and people can react," said geologist Gregg Wilkerson.

Studies have shown so far that the ShakeAlert system may give people a few seconds to 10 of seconds, depending on where the earthquake happens.

For instance, if the person is 40 miles from the earthquake, they will get 10 seconds notice. Sixty miles from the earthquake, they would get 20 seconds notice, and so on.

"An earthquake that is 300 miles away could take three or four minutes to arrive here, and so three or four minutes of warning for a major earthquake can mean the difference between living and dying," said Wilkerson.

The alert will most likely come up on your cellphone once the advancements are made.

Since the the 1960s, more than 400 sensor have been put in across the state. Wilkerson said they are old and outdated. For the ShakeAlert system to work reliably, another 700 sensors will need to be added and the existing seismometers need to be updated.

"It's just a question of with all the priorities facing our community, where's the best place to put our dollars," said Wilkerson.

Some lawmakers are fighting for an additional $38 million in order to update the current seismometers and put more in, as well as another $16 million for operation and maintenance each year.