It looks almost unremarkable: A pair of solar panels connected to a green power box in a clearing about five miles up Low Divide Road. Yet, it’s part of a system that could buy people a few precious seconds — enough to drop, cover and hold on — before an earthquake strikes.
The station on Mitchell Gianola’s property is connected to the early earthquake warning system operated by seismologists at the University of California, Berkeley.
According to Fabia Terra, early earthquake warning project manager for the UC Berkeley Seismology Lab, there are 431 stations between San Luis Obispo and the Oregon border. One-hundred and forty stations are currently funded for installation through the U.S. Geological Survey and the California Office of Emergency Services. A total of 252 stations are projected to be funded through CalOES and the USGS, according to Terra.
Gianola said Berkeley seismologists worked through late summer installing the station on his property and got it operational in September.
“I thought it would be a cool thing to have,” he said, adding that he responded to a letter from UC Berkeley. “You don’t make money on it. I donated the land. (It’s) a good thing for everybody.”
Seismologists at Berkeley, the California Institute of Technology and the USGS have been developing an early earthquake warning system since 2006, said Peggy Hellweg, operations manager for the UC Berkeley Seismology Lab. The goal, she said, was for scientists to detect a quake and determine its magnitude within approximately a few seconds and, if there is no earthquake, to “say it’s coming soon.”
Hellweg said it’s important for the system to both recognize moderate to big earthquakes that will cause damage as well as smaller temblors that are of interest to scientists. The system has been running in demonstration mode since 2012 and is now in a prototype production mode. It’s not yet a fully public system, she said.
“It’s clear in Northern California our network of stations was not good enough to do a very good job, and we have money from the state government and the federal government to improve the seismic network in Northern California and the rest of California,” Hellweg said, pointing out that the Cascadia Subduction Zone, which sits off the North Coast, is a significant seismic hazard for the state. “We know that we still don’t have enough stations up there to do a good job so we are still looking for seismic stations and the one we put on Mitchell’s property is one of the ones that is expanding our capabilities up in that area.”
Each station operates on its own and sends data to a central computer system where it’s processed in conjunction with information from other stations, Hellweg said. This is how seismologists determine the location of an earthquake, she said. The more stations reporting an earthquake, the better seismologists will be at figuring out its location, Hellweg said.
According to Hellweg, earthquakes have two types of waves, P waves and S waves.
“We want to be able to use the P waves to detect an earthquake and decide on the magnitude and tell people the shaking of the S waves is coming,” she said.
Hellweg used an earthquake in Berkeley on Thursday as an example.
“I live about three miles away on the ground, so horizontally three miles away,” she said, adding that the warning system sent her a message on her phone. “The time between my feeling the P waves and my feeling the S waves was two seconds.”
In most cases the early warning system could buy people seconds, Hellweg said. In the case of a large earthquake on the Cascadia Subduction Zone it could be a matter of tens of seconds, she said.
“Enough time to drop, cover and hold on,” she said. “It’s not going to give you time to drive away from the tsunami, but the tsunami is even slower than the S waves.”
According to Hellweg, though residents in Los Angeles County were able to download an app on their phones giving them a heads up before an earthquake hits, statewide the early earthquake warning system isn’t yet available to the general public.
Possibilities to publicize the information include the development of an app, a side band for public radio and television, sirens and the internet, Hellweg said. But, she noted, that the information needs to go out with as few delays as possible, especially if it’s a question of two to five seconds.
“We think of the earthquake as being a sudden P wave and a sudden S wave, but in fact the farther away you go the more rumbly they get,” Hellweg said. “Like thunder. If you’re next to thunder it goes bang, if you’re further away it goes rumble rumble rumble and the loudest part may not be at the beginning.”
Earthquakes are the same, Hellweg said. For a large temblor, the strongest shaking may not occur right when the S wave arrives, she said.
“Even if there’s only five seconds to the S wave arrival, it’s still worth telling people to get under your desk,” she said.
Hellweg also used twisting paper clips as an example of what happens to buildings during the repeated shaking of an earthquake.
“If the first paperclip gets bent it’s not a big deal if you’re not under the table,” she said. “But when it’s shaking back and forth and all of the pieces have gotten weak and fall apart, then you want to be under the table holding on.”
For more information about the early earthquake warning system being developed at UC Berkeley, visit seismo.berkeley.edu/research/eew_basics.html.
Reach Jessica Cejnar at firstname.lastname@example.org .