Artificial waves will put little 'Seaside' to test

Story Posted: Wed, Jul 18, 2007

Tsunamis - OSU researchers are ready to simulate waves from Northwest quakes
Wednesday, July 18, 2007
RICHARD L. HILL
The Oregonian Staff

Towering over a miniature "Seaside" like game-playing giants, the Oregon State University students carefully position yellow houses, red businesses and blue hotels along a shoreline.

But this isn't a game. The students are preparing the scale-model city -- a partial replica of the popular Oregon beach community -- to be clobbered by artificial tsunamis.

Their goal: give planners a better of idea of how a real tsunami would act if it struck the coast.

The students are part of a research team at OSU's Hinsdale Wave Research Laboratory that will be studying how tsunamis of various sizes would sweep through Seaside.

"It's a simplified model of the waterfront area and the bathymetry offshore," said Melora Park, a tsunami researcher at the high-tech wave laboratory. "The main interest is looking at the path of the tsunami. How is the wave going to channel through the city?"

The hotels resemble those in Seaside: Many residents may be able to escape the tsunami by going to higher floors in hotels and other buildings rather than trying to flee the city.

Daniel Cox, director of the wave lab, said the first phase of the project this fall will measure inundation patterns, while a second phase will take measurements of flow depth and speed. Cox said several waves will be generated in the 50-yard-long Tsunami Wave Basin, the world's largest tsunami lab, which was completed four years ago.

The biggest wave would simulate conditions produced by a 30-foot-high tsunami that scientists think could be generated by a magnitude 9 earthquake off the Northwest coast in the Cascadia Subduction Zone. The zone, where two tectonic plates converge, is nearly geologically identical to the area off Indonesia that caused an earthquake and tsunami in 2004 that killed more than 200,000 people.

Evidence indicates that subduction-zone quakes have occurred frequently off Oregon, with the last one striking in January 1700. Scientists say another one is inevitable.

Many Seaside residents recall the tsunami that swept through the city in 1964, the result of a magnitude 9.2 subduction-zone earthquake off Alaska. The "Good Friday Quake" triggered a tsunami that moved south toward Oregon and California, sweeping four children who were camping with their parents to their deaths at Beverly Beach north of Newport and causing significant damage at Seaside, Newport and other Oregon coast communities. It killed 11 people in Crescent City, Calif.

"We're watching this OSU project with a great deal of interest," said Deborah Treusdell, tsunami preparedness coordinator for Seaside. "The more we can learn about how tsunamis would affect our city, the better prepared we can be."

Richard L. Hill: 503-221-8238; richardhill@news.oregonian.com