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.
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
Members of UBC’s
Research Facility team
set up early-detection
sensors in Vancouver,
“You want to deliver actions
that people can take, like
moving away from windows.”