Death and destruction are great motivators. In late September, California Gov. Jerry Brown signed a bill that opened up the possibility of the state getting an earthquake early warning system similar to the one Japan uses.
The U.S. Geological Survey (USGS) has been researching such systems for several years, and it was through the existence of their research that California’s dream of an early warning system may now manifest. But it’s still not a sure thing. If California can’t find funding for the project – $23 million in initial costs, and another $60 million to cover five years of ongoing costs – it could be decades before a system emerges. But if a big earthquake hits San Francisco or Seattle soon, it could be great news for the project.
California Sen. Alex Padilla, who introduced the bill, stressed that such a system could reduce damage to critical infrastructure, improve emergency response times, and save lives. “When it comes to earthquakes in California, it is not a matter of if, but when,” Padilla said in a statement. “We need to develop this system without delay. California is going to have an earthquake early warning system – the question is whether we have one before or after the next big quake.”
California’s proposal is part of a larger USGS earthquake early warning system that would include California, Oregon and Washington. The exact scope of the project is not yet well-defined and how things progress will depend on the amount of funding that is secured, USGS Research Geophysicist Elizabeth Cochran said. “In seismology, we have a really hard time getting the funding before the earthquake happens,” she said, but right after a big disaster, people seem to become supportive for a time.
Seattle is due for a huge earthquake on the scale of the subduction quake of 1700. That earthquake, a magnitude 9 event, started offshore, generated a tsunami and caused the Earth to wobble on its axis. Getting an early warning for an earthquake that starts offshore, like the next big one in the Pacific Northwest will, Cochran said, would require offshore sensors, like those being installed as a part of Japan's early warning system.
Japan, which operates the only nationwide earthquake early warning system, began development in 1995 after the Kobe Earthquake. Engineers got an opportunity to see how their system performed during a large event when the Tohoku Earthquake hit in 2011, a magnitude 9 event that killed more than 15,000 people, injured more than 6,000, caused more than 2,000 to go missing, and either totally or partially collapsed more than 380,000 buildings.
Unfortunately, Cochran said, Japan’s system detected the Tohoku earthquake early, but underestimated its magnitude. The Japanese system predicted it would be a magnitude 8, but it turned out to be a magnitude 9. While that might not sound like a big difference, it is in fact substantial, she said, and affected how they responded.
The system works by constantly monitoring a network of sensors, Cochran explained. When there’s an earthquake, an algorithm is used to analyze the first few seconds to predict how large it will be. Low-frequency movements of seismograph needles indicate large earthquakes, and high-frequency needle movements indicate small earthquakes, she added.
For the last few years, the USGS has been using California’s existing sensor network to test out software on small earthquakes – mostly around magnitude 3. The system would need big upgrades to work as an effective early warning system, .
A few USGS scientists have software on their computers that sends them alerts when a small shake begins, she said. If this project gets funded, they would take the same approach as Japan, using as many alert methods as possible, including television, radio, smartphone and desktop computer applications. In addition, people would keep dedicated earthquake warning devices in their homes, similar to smoke detectors. “It’s important to have multiple ways of getting the information out because in Japan, for example, something like only 30 percent of the people who received an early warning received it through a smartphone,” Cochran said.
In California, the USGS predicted that about 200 new monitoring stations are needed and hundreds of existing stations would need to be upgraded. Command and control of the system would work by region, with regions likely consisting of Southern California, Northern California, Oregon and Washington.
“If we got the funding we needed tomorrow for California, then it would probably be about two years for us to get the system up and running and sending public alerts,” she said. Oregon’s and Washington’s seismic network coverage is not as comprehensive as California’s, however, so systems for those states would likely take longer to build, she said – maybe about three to five years after funding is secured.
In California, they would initially focus on the most populated areas, including San Francisco, Los Angeles, San Diego, and Ventura County. The network would not cover everywhere in the state, and some areas with small populations would not be covered, she said.
Other countries that have earthquake early warning systems include Taiwan, Mexico and Romania. Limited earthquake detection functionality also exists in various parts of the U.S., such as a system in Calistoga, Calif., that can alert area residents via siren, and a component of the Bay Area Rapid Transit (BART) that attempts to mitigate safety hazards in the event of an earthquake. Earthquake early warning systems that issue alerts widely are relatively uncommon, however.
Jennifer Strauss is the external relations officer for Berkeley Seismological Laboratory, where she works with politicians, explaining how the system works, and beta testers for the software. As they test, she said, they are able to separate what sounds like a good idea from what is feasible and useful.
If California can’t find funding for this project, she anticipated that there will be public uproar when the next big earthquake hits, because when the bill was passed, that made it look like the project was happening. Funding the project as soon as possible makes sense, she said.
“There’s a propensity for people to only look at what they want to spend money on right this minute, not 10 years down the road,” she said. “But if you can pay a relatively small amount of money right now to mitigate a gigantic amount of money later, I think it’s a good thing to do.”