West Coast not ready for tsunami, study says

SEATTLE – More than six years after the Indian Ocean tsunami shocked the world with its deadly power, communities along the West Coast remain ill-prepared for a similar event, concludes a report from the National Academies of Science.

An earthquake on the offshore fault called the Cascadia subduction zone could send waves crashing to the shores of Washington, Oregon and Northern California within minutes – not enough time for authorities to issue warnings or evacuate, said John Orcutt, the University of California, San Diego, seismologist who led the review.

“That’s what happened to Banda Aceh (in Indonesia), and the disquieting thing is that it could happen to us,” he said.

The only way to prepare people for such a fast-moving disaster is to deeply ingrain a simple message, Orcutt said: When the ground shakes or the water pulls back from the shore, walk uphill as quickly as possible.

States and local communities have undertaken education programs to spread that message, but results are uneven and approaches vary widely. In some towns, local residents removed tsunami evacuation signs because they didn’t want to scare off tourists, Orcutt said.

The report recommends a more uniform approach in terms of signs, warning messages, educational approaches and risk assessment.

“You need good coordination to deal with tsunamis,” added Oregon State University civil engineering professor Harry Yeh, who served on the review committee. “These kind of events are not local business – they’re everybody’s business.”

The analysis was requested by Congress, which boosted funding for ocean buoys and tidal gauges after the Indian Ocean tsunami. Today, a network of 39 buoys stretches from Alaska to South America, capable of detecting tsunami waves as they pass.

But the high-tech instruments are mainly useful for tsunamis generated by distant earthquakes – off the coast of South America, for example. In that case, several hours of warning time would allow for evacuation of coastal communities, Orcutt said.

But nearly a third of the buoys are out of service at any time due to malfunctions, Orcutt said. “That’s a very, very large number.” The report recommends that the National Oceanic and Atmospheric Administration beef up maintenance or design hardier instruments.

Tsunami awareness has increased tremendously since the Indian Ocean disaster, Yeh said. But with federal funding already dropping, it’s not clear how long that awareness will last.