The massive destruction and heartache caused by the series of tsunami in the Indian Ocean Sunday could result in more than 80,000 deaths. But a disaster of that magnitude is unlikely on Whidbey Island.
Officials say that Whidbey is relatively sheltered from the potentially explosive Pacific subduction faults along the Pacific coast, which limits the possibility of a tsunami — a very large ocean wave caused by an underwater earthquake or landslide.
A fault that runs through downtown Seattle could create other, equally dangerous phenomena, known as seiches (pronounced SAY-shh), said Dave Hollett, deputy director of the Island County Department of Emergency Services.
“It’s something that could happen here, but hasn’t for a long time,” Hollett said.
A seiche is created when an earthquake creates waves that are timed with the naturally occurring waves in an enclosed body of water. But even the chance of a secihe occurring in Puget Sound is remote, Hollett said.
“I’d say there’s a 5 percent chance of that happening here and that’s being real generous,” he said.
On Sunday, a 9.0 earthquake off the coast of Sumatra triggered a series of tsunamis that wiped out entire villages and killed thousands.
A tsunami has hit Whidbey Island, however. Two University of Washington scientists discovered traces of sand that washed ashore in Cultus Bay following an earthquake near Alki Point in Seattle. The scientists found a layer of sand approximately 1,000 years old in the marsh around the bay.
Local plan in effect
Hollett said that if a tsunami were to occur, a warning system is already in place. Many of the deaths in Asia could have been prevented by going to higher ground, but the Indian Ocean area has no warning system.
A rudimentary system of buoys that contain “tsunameters” peppers the Pacific ocean and are monitored by two stations, one in Hawaii and another in Alaska. If a shift in water pressure is detected, an alarm is sounded at the stations.
The tsunami warning system in the United States is a function of the National Oceanic and Atmospheric Administration’s National Weather Service, Hollett said. The regional, Alaska Tsunami Warning Center (ATWC) has an elaborate telemetry network of remote seismic stations in Alaska, Washington, California, Colorado and other locations. They are responsible for issuing warnings to British Columbia, Washington, Oregon and California for tsunamis generated off their coasts, he said.
If an earthquake occurs that is strong enough to trigger a tsunami, an alert is issued.
Island County has a fairly simple tsunami plan, Hollett said — get to high ground.
“Stay away from the coast and especially West Beach,” he said. “There’s not a lot we could do here except get to higher ground.”
A series of signs posted several years ago directs people toward high ground. If a tsunami were to hit the island, the Department of Emergency Services would be able to work with local law enforcement to ensure the safety and well being of people, Hollett said.
The biggest fear would be the loss of Deception Pass Bridge and the ferry docks, he said.
But Whidbey Island has a lot of factors that would prevent serious damage from occurring, Hollett said.
“We’re fortunate with the situation we’re in,” he said. “There’s not a lot of high buildings and there’s not a lot of exposure to seiches or tsunamis.”
