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Tue April 5, 2011
Scientists propose earthquake warning system
Earthquake scientists are hoping to build an early-warning system for Washington, Oregon and California. It would give typically about five to 30 seconds of notice that a big quake was starting. The scientists have been meeting this week to craft a proposal.
There’s no way to predict earthquakes. But once a big one starts, it sends out different kinds of shock waves that move at different speeds. One type is fast-moving, but barely perceptible. These are called P-waves. They arrive before the slow traveling but damaging shock waves (called S-waves).
So, if you have precise sensors, they can detect the fast-moving waves and send out alarms.
After the devastating Kobe earthquake in 1995, Japan spent half a billion dollars installing such a warning system, as Steve Henn reported for PRI's Marketplace. And it worked last month – at least enough to give people far from the epicenter a warning:
"More than a minute before the ground began to shake in Tokyo, texted warnings hit millions of cell phones; stations interrupted their broadcasts; bullet trains came to a halt; and factories got urgent e-mails to secure their assembly lines."
A similar warning system has been discussed for years in California. The obstacles include the huge price-tag, and the fact that any such system includes inevitable false-alarms, according to a report by Amy Standen for NPR in 2009. Plus, the warnings might only offer a few seconds advance warning, leaving some to wonder if the system would really provide much benefit.
Scientists from all three Pacific coast states have been meeting in Berkeley, Calif., on April 4-5, to devise a coast-wide warning system. It would take years to install hundreds of the sensitive seismometers and to create a warning network.
[UPDATE: By the end of their two-day meeting, the scientists projected it would cost about $80 million to finish the California warning system. John Vidale of the University of Washington said it would cost roughly another $65 million, over five years, to wire-up the Pacific Northwest. Vidale also says, in a best-case scenario, during a monster subduction quake of the Washington coast, people in the Seattle area might get four minutes of warning.]
Presumably, the vivid images of Japan's ordeal might make federal funding seem more realistic.