earthquakes can't be stopped — but project teams are working to limit their worst effects
No one knows exactly where and when the next big earthquake will occur. But just a few seconds of warning can save lives, so project teams around the world are working to mitigate the effects of quakes by alerting people to impending seismic activity.
In Chile, 2010's 8.8-magnitude earthquake—one of the biggest ever recorded—proved a turning point. After that earthquake and resulting tsunami killed more than 500 people and caused around US$30 billion in damage, the government created a new early-warning system and upgraded its response protocol. Between 2013 and 2015, project teams installed 130 coastal GPS sensors, each costing US$20,000. The investments paid off when an 8.4-magnitude quake struck the coastal city of Coquimbo in September 2015. Sirens and mobile-phone warnings urged residents to leave the area, and the government quickly evacuated 1 million people. Only 13 died.
“Early-warning systems can save millions of dollars and lives, even though we're just talking about seconds,” says Paul Bodin, PhD, network manager of the Pacific Northwest Seismic Network, University of Washington, Seattle, Washington, USA. “People get under their desks, for example, rather than waiting to feel it and figure out what it is and then put themselves in a safe position.”
Chile and Japan have become leaders in earthquake preparedness, and countries like Canada and the United States are now trying to catch up. But traditional retrofitting projects aren't cheap—Japan's government is sponsoring a US$26.5 billion program to prepare for the 2020 Summer Olympics in Tokyo, for example. It comprises 363 projects to quake-proof buildings and infrastructure.
Facing public-funding shortages, North American project teams are devising early-warning systems that deliver major benefits but are also relatively cheap. In the earthquake-prone Pacific Northwest, a team at the University of British Columbia in Vancouver, British Columbia, Canada created an early-warning system that uses underground sensors to detect vibrations. The program began installing either sensors or alarms in 59 of the city's Catholic schools in 2014, and last year expanded to 62 area schools at a cost of CA$15,000 to CA$30,000 per institution. The schools and the British Columbia Ministry of Transportation jointly sponsored the projects.
“Early-warning systems can save millions of dollars and lives, even though we're just talking about seconds.”
—Paul Bodin, PhD, Pacific Northwest Seismic Network, University of Washington, Seattle, Washington, USA
Team members can't just install sensors and then walk away, however. They have to train the system's users: the teachers and students. “We developed a protocol they have to follow if the alarm goes off,” says Carlos Ventura, PhD, director of the Earthquake Engineering Research Facility at the University of British Columbia in Vancouver. That protocol involves showing teachers how to instruct students to get under their desks within just five seconds of hearing the alarm and then evacuating the building after the shaking subsides.
The team members gleaned valuable lessons from the pilot test project. A continuously ringing siren didn't allow teachers to tell their pupils what to do, so the team adjusted the siren to ring in intervals. The team also learned that some users respond better to voices, so the warning system now includes sirens, automated instructions and a public-address speaker through which school officials can speak.
Another Pacific Northwest early-warning project team also learned from its pilot phase. Sponsored by the U.S. Geological Survey and the Gordon and Betty Moore Foundation, the US$38 million ShakeAlert system would provide advance notice to people in California, Oregon and Washington. Sensors detect P-waves, the first waves of energy from earthquakes, which rarely cause damage, to predict the magnitude of the slower but more destructive S-waves. “It's like looking at lightning to predict the thunder,” Dr. Bodin says. The system sends users a digital map that indicates the quake's location and the estimated time of the shaking.
Yet the team learned during the pilot it wouldn't be enough just to warn users that the quake was on its way. ShakeAlert also needed to tell users how to respond. So the project team incorporated an alarm and an automated voice announcing the quake, the time of impact and instructions. “You want to deliver actions that people can take, like moving away from glass windows,” Dr. Bodin says. The team also decided to send warnings to users via text message rather than just email.
“You want to deliver actions that people can take, like moving away from windows.”
Members of UBC's Earthquake Engineering Research Facility team set up early-detection sensors in Vancouver, British Columbia, Canada.
The ShakeAlert team also learned from Japan. In 2011, Japan's early-warning system didn't predict a devastating 9.0-magnitude earthquake, in part because the system used only seismic data, which measures shaking, and not GPS data, which measures displacement. “A large earthquake doesn't only shake; the slip on the fault line is so large it permanently displaces the ground,” Dr. Bodin says. So the new system's requirements included incoming GPS data.
That posed the challenge of working with other agencies gathering that data, though. “We need to make it part of all their missions to support our early-warning system,” Dr. Bodin says. In seismically active areas like the U.S. West Coast, the stakes couldn't be greater. —Novid Parsi
PM NETWORK MAY 2016 WWW.PMI.ORG
MAY 2016 PM NETWORK