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ShakeAlert Is Shaking Things Up In Earthquake Detection

October 19, 2018
by Elena Leander

Today, millions of people practiced their “drop, cover, and hold on” for the Great California ShakeOut. The annual earthquake drill, held a day after the anniversary of the 1989 Loma Prieta quake, celebrated its 10th birthday—with a twist. This year, for the first time, ShakeOut partnered with ShakeAlert 2.0, an earthquake early warning (EEW) system created in collaboration with the Seismology Lab at UC Berkeley. According to Lab Director Richard Allen, the warning system uses a West Coast-wide network of sensors to detect the quakes before they hit and share that information with its partner organizations.

Bay Area Rapid Transit (BART), the first of ShakeAlert’s 40 current partners, has been receiving earthquake signals for the last five years. And just this past Monday, they held a public demonstration of their system. With the train car packed full of eager media teams and politicians, BART simulated an emergency response which, Allen admitted, was a little anticlimactic without an actual quake.

Allen noted that if everyone received a warning and took cover beneath a sturdy table, the number of earthquake injuries could be reduced by 50%.

“You know there was so much noise from all the chatter, that people didn’t actually realize they were doing it because you know all they did was slow and stop the train. They didn’t even stop it, they actually just slowed the train down to 20 mph and then they just sped up.” Laughing, Allen continued, “So the first thing I had to do at the press release immediately following was explain to everybody in the media, why it was so uneventful.”

Had there been an actual earthquake, Allen explained, the slowing down of BART could have prevented potential derailments and injuries. Which, for the nervous BART-rider, should help alleviate some earthquake anxiety.

BART is only one piece of a much larger earthquake safety puzzle, however. The list of automated systems that could benefit from the early warning system includes elevators, gas valves, hospital equipment, and more. Perhaps most importantly, the warnings could be used to get people to safety a bit sooner—not to change protocol, in other words, but to make it more efficient.

“The difference is now you’re underneath the sturdy table before the shaking starts,” Allen said. “Rather than, first of all, feeling a little bit of shaking, kind of looking at somebody else in the room, did you feel that? Did I feel that? Is that an earthquake? What do we do now? I forgot what we do now. By the time you’ve actually decided you’re going to do something, the earthquake is over, kind of thing.”

In the Loma Prieta and Northridge earthquakes, more than 50% of injuries were caused by things falling on people or people falling on things. Allen noted that if everyone received a warning and took cover beneath a sturdy table, the number of earthquake injuries could be halved.

As to people’s fear that an early warning might just create needless panic and make things worse, Allen says “there’s actually no evidence for that.” In fact, panicking due to an early warning has been listed as one of the three myths of human behavior in a crisis by the Cal Office of Emergency Services. The myth has since been busted by research that looks at the public’s response to earthquake early warning systems in other countries.

There are perks to having an earthquake detection system in your backyard, says Allen. Simply put: more sensors means accurate readings for everyone.

Mexico and Japan have both had well-developed EEW systems for over a decade, and earthquake-prone California is arguably overdue. So what’s the hold-up? Geography, Allen explains. In Mexico and Japan, earthquakes are caused by tectonic activity offshore and underwater, which allows more time between when the quake first hits and the effects are felt on land. But in California, major fault lines run directly beneath high-density cities. The Hayward Fault bisects the East Bay, while the Santa Monica fault lies right beneath Los Angeles. And as most residents are aware, these fault-straddling cities are overdue for the next “Big One”—another reason to implement early earthquake technology warnings sooner rather than later.

Besides geography, there’s another limiting factor: the number of sensor stations. Phase 1 roll out of ShakeAlert 2.0 has been possible thanks to the installment of nearly 70 earthquake sensor stations, but Allen and his team are looking to install 90 more. Because the sensors are constantly gathering and sending back data to the lab, more sensors means a quicker detection time and a lower likelihood of false alerts. The sensors in place are concentrated in the Bay Area and Los Angeles, and the Seis Lab is currently looking for private landowners around the state who would be interested in having one installed in their backyard. The station itself is about the size of a small garden shed, just big enough to host a couple of computers, a few batteries, and the sensor instrument itself, which is a metal cylinder that goes into a hole a few meters deep. Once installed, the stations are low-maintenance; the sensor awaits detection of the seismic P-waves that come before more destructive S-waves, all the meanwhile streaming data for ongoing research.

In short, more sensors means more accurate readings, but the challenge remains to get the signal out to everyone.

As for what’s next, the Seismology Lab is keeping busy. In addition to installing new sensor stations, they’re working on rolling out an upgrade to MyShake (an app and ongoing research effort developed by the lab).

“We’ve been working on getting ShakeAlert out there for over a decade,” Allen says.“It’ll be done when everyone gets the warning on their phone, and we’re not there yet. But now there’s no question that ShakeAlert is open and ready for business.”

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