Re-creating Seaside

Story Posted: Sun, Jun 10, 2007

One miniature at a time

By KYLE ODEGARD
Corvallis Gazette-Times

Daniel Cox held up a yellow wooden house about the size of a shoebox, a model that looked plucked from some brightly colored, giant Monopoly set.

“This is a residential home. They’re building the hotels right now,” said Cox, the director of Oregon State University’s O.H. Hinsdale Wave Research Laboratory.

But these aren’t fictional buildings.

The lab’s Tsunami Wave Basin is re-creating the tourist center of Seaside at a 50th of the actual size so researchers can repeatedly slam tidal waves into it.

Officials of the Oregon coast town are thrilled.

The $1 million study could help save lives. It will be added to other tsunami preparation efforts in Seaside, such as bridge renovations, said Kevin Cupples, the city’s planning director.

“We think it will be one more piece of good information to add to the mix. … Several people in the community are going down to check out the lab,” said Deb Treusdell, Seaside’s tsunami preparedness program coordinator.

OSU wanted to look at how a tsunami would impact an actual community and decided to choose one in Oregon, Cox said.

The 36-foot-wide model will capture a slice of Seaside three blocks north and south of Broadway, a street dotted with tourist shops and arcades. The miniature city will stretch west from the popular Turn-Around on Broadway a few blocks east to the Necanicum River.

The Promenade is one of the prominent features of that area. At the Turn-Around, the concrete walkway sits atop a wall 15 feet above the sand.

The model buildings will be put in place this summer, but a big part of the replica is a mockup of the sea floor leading up to the town. It cost about $100,000 to pour and sculpt the concrete floor of the Tsunami Wave Basin, Cox said.

The study hopes to determine the size of a potential tsunami in Seaside and whether it would be better to run for the hills or get to an upper floor of a beachfront hotel.

Scientists believe a large tsunami — a 35-foot-high wall of water rushing over the beach in Seaside — could be caused by a Cascadia subduction zone earthquake just offshore.

Researchers know that one occurred on Jan. 26, 1700. Such an event today would be similar to the Indian Ocean tsunami of 2004, which several people survived through “vertical evacuation” — taking refuge on the second story of a hotel or bar.

“They call it a 500-year event,” Cox said. “There’s a chance it could happen sooner.”

In fact, experts say, there’s a 14 percent or greater chance that it could occur in the next 50 years.

Such a tsunami would take about 15 to 20 minutes to hit the Oregon coast, according to the Oregon Department of Geology and Mineral Industries. It would take just about that long to flee from the beach to higher ground outside the tsunami-flooding area.

“The current evacuation plan leaves no margin for error,” Cox said.

The town actually slopes downhill from the shoreline, which stretches out the flooding zone, and people heading for the hills would need to cross a river and creek on bridges that might not survive the initial earthquake, Cox said.

Cupples said that with major bridge renovations, it is hoped that a route will remain open from downtown Seaside and from the northern end of town at 12th Street.

The Clatsop County community has a population of nearly 6,000. On a sunny summer day, tourists could triple the number of people in the city, Cox said.

“There’s a tsunami coming so quickly, there are so many people, and there’s so far to go,” he added, summarizing potential problems for the city.

A tsunami from an Alaska-area earthquake actually hit the Oregon coast on March 28, 1964, killing four children camping near Newport, according to the National Oceanic and Atmospheric Administration. Seaside suffered $276,000 in damage, mostly near the Necanicum River, and one person died from a heart attack.

The OSU Wave Research Laboratory was created in 1972. The Tsunami Wave Basin opened in 2003 at a cost of about $6 million. At about 50 meters by 25 meters, it is the world’s largest tsunami research facility, Cox said.

An open house and demonstrations of the Seaside model will be held on Nov. 9 and 10, during Dad’s Weekend at OSU. The model will be used for research from this fall until next April.

The National Science Foundation and Oregon Sea Grant are funding the studies.

The OSU Wave Research Laboratory includes a 104-meter long wave flume and is also used by other universities for research. The Tsunami Wave Basin will be the site of other studies this summer, including research on the scouring effects of tsunamis on beaches by Princeton University and an investigation of the impact of hurricane winds on residential structures by Colorado State University and OSU.

The wave basin previously was used for a navigational study for the state of Washington’s ferry system. The Seaside study is a big step forward in research, however.

“This is one of the first projects to model tsunami inundation for a real coastal community,” Cox said. “We are looking at a coastal community. It’s an exciting time to try to really look into this problem.”

Kyle Odegard can be contacted at kyle.odegard@lee.net or 758-9523.