California will likely roll out a limited public earthquake early warning system sometime next year, researchers building the network say.
New earthquake sensing stations are being installed in the ground, software is being improved, and operators are being hired to make sure the system is properly staffed, Caltech seismologist Egill Hauksson said at a joint meeting of the Japan Geoscience Union and American Geophysical Union.
The new sensor stations are particularly important for rural Northern California, where gaps in the network have put San Francisco at risk for a slower alert if an earthquake begins on the San Andreas fault near the Oregon border and barrels down to the city. Last summer, California lawmakers and Gov. Jerry Brown approved $10 million for the earthquake early warning system.
"We're starting to add additional stations very rapidly. The contracts are now being signed for the state funding, which is largely being spent on putting out new stations," said Richard Allen, director of the Berkeley Seismological Laboratory. "They're going to come online in the next year or so, so there will be pretty rapid expansion of the seismic network over the course of the next six months to two years."
The network is being built under the leadership of the U.S. Geological Survey, with development from scientists at Caltech, UC Berkeley, the University of Washington and University of Oregon. The USGS has previously stated that it plans to do a limited public rollout of earthquake early warning alerts by 2018.
More work still needs to be done to properly educate Californians on how to react safely when they get an early warning to an earthquake, said seismologist Lucy Jones.
How the system would be used
Examples of a limited public rollout include having more school classrooms be linked to the early warning system, giving students seconds or perhaps more than a minute of warning that an earthquake is on the way and to drop, cover and hold on underneath their desks. Scientists have also invited private companies to become test users of the early warning signal.
Some agencies are already using the early warnings. BART, a commuter rail system in the San Francisco Bay Area, already programs its trains to slow down when alerted about an incoming earthquake, which reduces the risk of derailment. And private companies are already looking at ways to make the early warnings more useful, such as signaling a firehouse station to open up firehouse doors before a power outage starts or the building is damaged.
Eventually, people will be able to receive on their phones and computers an alert that will say, "strong shaking expected at your location," said Diego Melgar, research geophysicist at the Berkeley Seismological Laboratory. "I think what is most likely to happen is that the rollout will be in stages, where the end goal is a West Coast-wide—from the Mexico-U.S. border to the Canadian-U.S. border—system. But it will probably be in stages."
One way of rolling out the system in stages is first issuing the alerts to a limited number of people, then slowly expanding it. Eventually, the system could be expanded to be made available in a geographically limited area, such as Los Angeles and San Francisco, before expanding to a full public alert system, Melgar said.
"We want to make sure it's bulletproof before it goes out to the public," Melgar said.
Researchers have made progress on the seismic network outside of California. In April, the USGS expanded the ShakeAlert earthquake early warning system to Oregon and Washington state, for the first time creating a unified prototype system covering the American West Coast between the U.S. borders of Mexico and Canada.
Utilities in the Pacific Northwest have begun to link into the system. An Oregon utility, Eugene Water & Electricity Board, plans to use alerts to lower water levels in a canal that sits above a residential neighborhood. The utility also wants to use alerts to stop turbines at a river power plant, according to a statement from the University of Washington.
The areas where the seismic network has the highest concentration of stations are in the Los Angeles and San Francisco areas, but more sensors are needed in rural Northern California, Oregon and Washington. Too few stations means that, for instance, Los Angeles could also see warning delays from an earthquake that starts in Monterey County and moves south along the San Andreas fault.
Other funding has helped. The budget deal reached in Congress in May allocated $10.2 million for the early warning system for the federal budget year that ends in September.
California behind other quake-prone areas
Countries around the world have implemented earthquake early warning systems with success, such as Japan, which programs its high-speed trains to slow or stop if the warning system detects an earthquake is coming.
Even seconds of warning to drop, cover and hold on would save many lives in an earthquake. Beyond that, alerts would give doctors time to halt surgery. Eventually, bigger benefits are expected: technology to open elevators at the next floor, sparing occupants from being trapped, and warnings that could halt the flow of natural gas through major pipelines, preventing catastrophic fires.
How the system works
The early warning system works on a simple principle: The shaking from an earthquake travels at about the speed of sound through rock — slower than the speed of today's communications systems. That means it would take more than a minute for, say, a magnitude 7.8 earthquake that starts at the Salton Sea to shake up Los Angeles, 150 miles away, traveling on the state's longest fault, the San Andreas.
The prototype system has had some early successes. When a magnitude 6.0 earthquake hit Napa in 2014, the system gave researchers in San Francisco about eight seconds of warning before shaking began. Last year, 30 seconds of warning reached downtown L.A. before the ground shook from a magnitude 4.4 quake centered near Banning.
Officials estimate it will cost $38.3 million to build the system and $16.1 million annually to maintain and operate it.