Gov. Brown seeks to beef up California's earthquake early warning system
Sanden Totten
May 16 2016FILE - In this Sept. 13, 2011 file photo, Anthony Guarino Jr., a seismic analyst at the California Institute of Technology, demonstrates an early earthquake warning system in Pasadena, Calif. California state Sen. Alex Padilla is holding a hearing Wednesday, Oct. 15, 2014, at San Francisco City Hall to get an update from the director of the Governor's Office of Emergency Services about plans for a comprehensive statewide earthquake early warning system. (AP Photo/Reed Saxon, File) Reed Saxon/AP
California's pilot earthquake early warning system is one step closer to being ready for prime time thanks to Gov. Jerry Brown's latest budget proposal. In it, he asks the state legislature to allocate $10 million for the project.
"This is a huge thing for us and a great contribution from the state," said Ken Hudnut, science advisor for risk reduction with the U.S. Geological Survey, which is helping develop the early warning technology.
The system works thanks to sensors placed near faults that detect the rumbling of a quake just as it starts.
Once these sensors get a signal they send out an alert that travels faster than the speed of the quake's seismic waves. Computers receive and interpret that signal before issuing a warning.
Once fully developed, the network could give up to a minute's worth of lead time before shaking reaches major cities, though in many cases it would only provide seconds, if any warning at all.
Earthquake early warning systems like ShakeAlert work because the warning message can be transmitted almost instantaneously, whereas the shaking waves from the earthquake travel through the shallow layers of the Earth at speeds of one to a few kilometers per second (0.5 to 3 miles per second). This diagram shows how such a system would operate. When an earthquake occurs, both compressional (P) waves and transverse (S) waves radiate outward from the epicenter. The P wave, which travels fastest, trips sensors placed in the landscape, causing alert signals to be sent ahead, giving people and automated electronic systems some time (seconds to minutes) to take precautionary actions before damage can begin with the arrival of the slower but stronger S waves and later-arriving surface waves. Computers and mobile phones receiving the alert message calculate the expected arrival time and intensity of shaking at your location. USGS Much of it depends on where the quake starts and how many sensor stations are in place near the fault in question. Currently there are around 470 advanced sensors in the network placed near major faults. Ideally, the system would have more than 1,100.
"Right now it's in a pilot phase," Hudnut said. "There are some places where the station density is just not enough," Much of Brown's proposed funding would go toward building more of these sensor stations.
Developed in collaboration with Caltech and UC Berkeley, a bare-bones version of the warning system has been up and running for years.
It gave researchers in L.A. 30 seconds of warning before seismic waves from a 4.4 quake in Banning reached downtown last year. In 2014, it was able to warn researchers in San Francisco eight seconds before the shaking from the 6.0 Napa quake arrived.
Screenshot of the User Display of CISN ShakeAlert during the 2011 M3.3 Channel Island earthquake in Southern California. Cal Tech
All told, the system will require an estimated $39 million to build out across the West Coast. After that, it's expected to need $16 million a year to operate.
The federal government chipped in $8 million last year and is expected to do the same this year.
Rep. Adam Schiff (D-Burbank) has championed the system and helped secure that money. He thinks the federal funds are part of what inspired Brown to change course and include the warning system in his budget proposal as well.
Previously Brown had said he wanted funding for the system to come from Congress, grants and private companies.
"California is now leading the way," Schiff said. "We hope that Washington State and Oregon follow suit."
Peggy Hellwig, with the Berkeley Seismological Laboratory, said a major priority for the new money would be beefing up the number of sensors along the San Andreas Fault.
"In Northern California in particular, the coverage is spotty in most places except the Bay Area," Hellweg said.
Right now, her team plans to add sensor stations along the San Andreas from San Luis Obispo north to the Bay Area, as well as from Napa to Mendocino.
Equipment and instillation for each station can cost anywhere from $40,000 and $80,000 and often involves finding partners willing to allow their land to host the gear.
Russell Oliver removes the plastic from a brand new STS 2.5, a top of the line motion sensor. This sensor is part of a pilot system that could provide Californians with up to a minute of warning before an earthquake reaches them. Sanden Totten/KPCC
Another challenge is figuring out how to disseminate the warnings.
Right now, some pilot partners, like Bay Area Rapid Transit, receive warnings and can slow or stop trains to avoid accidents during a quake.
Ideally, alerts will go out to trains across the state, as well as hospitals, schools, firehouses, factories and amusement parks, so each one can brace for shaking and hopefully avoid loss of life and severe property damage.
The dream for the system though, is to one day send notices to everyone via cell phone technology, so anyone near a quake can drop, cover and hold on. However, figuring out a way to send an alert to potentially millions of phones without clogging the network and slowing things down too much is proving to be quite a challenge.
Hellweg says her team has met with communication experts looking for a solution but so far they haven't found one.
"But we think there is a solution that can be implemented," she added.
Japan, Taiwan and Mexico all have early warning systems already in place, and much of the technology they use was developed in California. Funding has been a perennial problem for getting the U.S.'s first system up and running.
"Government is inherently not that good at acting in advance of a tragedy,"Schiff said. "I am hoping we can get the job done and not kick ourselves that we didn't do it sooner."
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