Lab's 'tsunami' floods a town

Story Posted: Fri, Sep 14, 2007

Research - Experts at Oregon State use their state-of-the-art facility to study a disaster's impact on Seaside

Friday, September 14, 2007
RICHARD L. HILL
The Oregonian Staff

CORVALLIS -- With the gentle click of a computer mouse, a powerful tsunami surged through a Lilliputian-size Seaside on Thursday, inundating the city's landmark beachfront turnaround, businesses, homes and streets.

While the real Seaside was dry, scientists at Oregon State University were using the nation's most sophisticated tsunami research facility and a miniature-scale model to study what would happen if a fast-moving, 35-foot-high tsunami hit the community.

The partial replica of several blocks of the popular beach community's waterfront -- complete with a "Welcome to Seaside" sign -- will be repeatedly flooded with artificial tsunamis this fall and winter in the basin.

Daniel Cox, director of the world's largest tsunami lab, said the project's first phase will examine how the water will channel through the city. A second phase will measure flow depths and speeds, a third phase will examine the water force on buildings, and a final step will look at the destructive movement of debris, including cars and trucks.

Researchers are exploring whether Oregon coastal communities should consider "vertical evacuations" -- going to higher floors of hotels and other newer quake-resistant buildings -- as well as setting up evacuation routes for people to flee to higher ground.

"Many lives were saved in the Sumatra earthquake in 2004 when people just went up in reinforced concrete buildings," Cox said. "Maybe that's an option when you only have 20 to 30 minutes to escape from a tsunami produced near the coast."

Cox said several waves will be generated in the 50-yard-long Tsunami Wave Basin, completed four years ago with $5 million from the National Science Foundation. The $170,000 Seaside project is being funded by Oregon Sea Grant.

Low-lying Seaside is one of the most tsunami-savvy Oregon communities, with drills, public-education programs and evacuation routes. City officials have welcomed their city being used as a model, saying it would help make them even more prepared for a tsunami.

Oregon's coastline faces tsunamis from near and far. A 35-foot-high tsunami is what scientists say 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 a geological twin to the area off Indonesia that caused this week's large earthquakes and a 10-foot-high tsunami. It is the same area off Sumatra that produced the powerful 2004 quake and tsunami that killed 230,000 people in a dozen countries.

Evidence indicates that subduction-zone quakes have occurred about 20 times in the past 10,000 years off Oregon, with the last one striking 300 years ago.

In 1964, Seaside, Newport and other Oregon coastal towns were damaged by a tsunami caused by the magnitude 9.2 "Good Friday quake" in Alaska. The earthquake triggered a tsunami that moved south toward Oregon and California, killing four children at Beverly Beach north of Newport and 11 people in Crescent City, Calif.

"Oregon is vulnerable to tsunamis, and that's why we decided to do this project," Cox said. "We want this research to have a practical benefit. It could result in saving lives."

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