Another Real-Life Test for an Earthquake Early-Warning System Under Development

An earthquake early-warning detection system being developed for the Pacific Northwest got a real-life test last week when a magnitude 4.8 event centered near Victoria, British Columbia, was widely felt across the border in parts of Washington state’s Puget Sound region.

While the Dec. 29 quake was not strong enough to cause damage, it was the largest to strike the region since the Feb. 28, 2001, Nisqually earthquake , a magnitude 6.8 seismic event centered near Olympia, Washington.

The Pacific Northwest Seismic Network , based at the University of Washington, has been working with the U.S. Geological Survey and academic partners in California and Oregon to develop and deploy an earthquake early-warning alert system for the West Coast.

A similar system is being developed by the University of British Columbia and during last week’s quake, a seismologist at his home in the Vancouver area reported receiving an alert 13 seconds before the shaking started there, according to the CBC. Early-warning alarms connected to the UBC system have been installed at 61 schools in British Columbia.

On the U.S. side of the border, the early-warning system being developed by the Pacific Northwest Seismic Network successfully detected the Victoria-area quake within 10 seconds , before the strongest shaking reached the surface, University of Washington seismologist John Vidale told MyNorthwest.com.

While such early-warning systems can’t predict major earthquakes before they strike, they can, depending on a quake’s epicenter, give populated areas just enough warning before destructive S-waves hit.

For instance, in the event of a future magnitude 9.0 Cascadia Subduction Zone megathrust earthquake off the coast of Oregon and Washington state, an early-warning system could give the city of Seattle three or four minutes of advanced notice that significant shaking is on the way.

For a major quake originating on the San Andreas Fault near the Salton Sea in Southern California, the city of Los Angeles could have upwards of a minute warning before the shaking starts, as shown in this visualization using a theoretical magnitude 7.8 event.

That can’t prevent damage, but the advance notice, relayed through cellphones and other means of communications, can give people enough time to seek sturdy shelter to ride out a serious earthquake, reducing injuries and fatalities.

And when early alerts are integrated into transportation networks, hospitals and industrial facilities, that could allow moving trains to slow down or stop, alert surgeons to halt delicate procedures in progress in the operating room or allow manufacturers to shut down vulnerable facilities and systems before the serious shaking starts. Warnings transmitted over loudspeakers in vulnerable areas, like Seattle’s Pioneer Square—where older buildings sustained heavy damage in the 2001 Nisqually quake—could give people in those areas enough time to find a safer spot.

The success of the early-warning systems are dependent on two major factors: The proximity of a major earthquake's epicenter to the person receiving the alert and the ability of the system to detect the quake and relay the warning.

Following the Aug. 24, 2014, magnitude 6.0 earthquake in Napa County, California, an early-warning system being tested in the Bay Area alerted seismologists at the University of California at Berkeley 10 seconds before shaking started there, about 40 miles from the epicenter. The Bay Area Rapid Transit system's rail network is part of the early-warning system and in the event of shaking of a magnitude 3.1 quake, trains traveling 30 mph or slower would have stopped while trains traveling at higher speeds would have slowed. (The Napa quake struck in the overnight hours when no trains were in service.)

Vidale told MyNorthwest.com that there’s still work to be done before making the Pacific Northwest early-warning system available to the public. But in follow-up comments posted on the PNSN’s Facebook page , he noted that steady progress is being made:

We're now adding in the routines that mix in GPS with seismic recording to be able to rapidly identify the largest earthquakes accurately, a job that is impossible to do with seismometers alone. Also, we're installing instruments with sufficient density and quality, especially along the coast, to most rapidly and accurately assess earthquakes.

Having enough seismic sensors deployed around the region is important. During an early real-life test of the Pacific Northwest early-warning network last February, the system was slow to detect a magnitude 4.3 quake by 18 seconds . As The Associated Press reported at the time, there weren’t as many sensors deployed in the area Washington state where that quake originated, near the town of Cle Elum in the Cascade Range east of Seattle.

Although such earthquake early-warning systems have been used in Japan and Mexico for years, the United States has lagged behind and is playing catch up.

Funding is not yet available for a fully built-out system to cover the entire West Coast, but incremental progress is being made to develop such a comprehensive system.

In August, the U.S. Geological Survey awarded a $4 million grant to UC-Berkeley, CalTech, the University of Washington and the University of Oregon, to continue work on the early-warning system, called ShakeAlert.

Cost estimates for a comprehensive system for the West Coast are around $38 million with annual $16 million price tag for maintenance and operations costs. The 2016 omnibus spending bill passed by Congress last month included $8.2 million for the continued development of the earthquake early-warning system .

(Top photo by Joseph Sohm / Shutterstock.com )