It’s a disaster waiting to happen: Experts say a major earthquake off the coast of Washington State would hurl a tsunami across the Pacific Northwest coast, killing tens of thousands.
The wall of water would inundate low-lying coastal areas of Washington, Oregon and Northern California in minutes, leaving much of the region beneath 10 feet or more of seawater, the New York Times reported.
“The fact of the matter is that if a tsunami occurs tomorrow, we are going to lose all of our children,” said Andrew Kelly, superintendent of the North Beach School District, which includes Ocean Shores, Washington.
He’s among a growing number of local officials calling for a network of elevated buildings and platforms along the coast to provide refuge for residents who’d otherwise be doomed. Residents of Ocean Shores and neighboring hamlets west of the state capital, Olympia, will decide on Feb. 15 whether to approve a bond measure to build the structures.
Washington State officials have proposed a network of 58 vertical evacuation structures along the outer coast that could provide 22,000 people with escape options. Each structure could cost about $3 million.
Scientists have warned for years about another catastrophic earthquake from the Cascadia “megathrust” fault that stretches 600 miles from Vancouver Island, British Columbia, to Cape Mendocino, Calif. The last big one occurred in 1700.
A quake from the fault, about 70 miles offshore, could cause the shoreline to immediately drop by several feet. The shock beneath the sea would send massive waves hurling toward shore, hitting land within 15 minutes.
Many stretches of the Northwest coast lack bluffs or high buildings. The death toll could be unfathomable – surpassing any other natural disaster in U.S. history, according to the newspaper.
As many as 70,000 lowland residents would be engulfed by the large tsunami, according to Washington state computer models 9.0-magnitude quake. Half wouldn’t have access to high ground.
In Oregon, between 5,000 to 20,000 could die in a similar event. Additional deaths are expected in Northern California. In Crescent City, a tsunami that rolled in from Alaska in 1964 killed 11 people.
A catastrophic quake could bring widespread devastation to property and lives across a 140,000-square-mile region, including Seattle and Portland.
The chance of a 9.0 megaquake on the Cascadia fault in the next 50 years is one in nine, according to the research. The odds of a smaller but still powerful earthquake greater than 7.0 magnitude are one in three. Put another way, the last quake on the fault took place in 1700, and scientists expect another big one every 430 years. Include smaller but still powerful quakes and the timeline in some areas shrinks to every 250 years.
Few places are more vulnerable than Ocean Shores, where 6,700 residents live on a six-mile-long peninsula. A tsunami could put it 23 feet under water.
Those toward the southern end would be about eight miles from high ground. Many residents might have only 10 minutes after the shaking stopped before being overrun by the surge
[NYT] – Dana Bartholomew
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