Thousands of people living along the U.S. Pacific coastline from Northern California to Washington state could survive a powerful tsunami, as long as they are prepared to walk briskly to higher ground, a researcher said on Tuesday.
About 95,000 people live on a 620-mile stretch of the Pacific Northwest coast which is considered vulnerable to a tsunami triggered by an earthquake offshore, scientists said.
A research team assessing the risk to that population found that in many areas, people can be ready to move out of danger in the minutes between the earthquake and the tsunami by simply walking, according to a study published in the Proceedings of the National Academy of Sciences.
“We’ve identified several towns where moving faster can mean the difference between life and death,” said the lead author of the study, Nathan Wood, a geographer with the U.S. Geological Survey.
The study said 49 cities, seven tribal reservations and 17 counties in Northern California, Oregon and Washington are “directly threatened by tsunami waves” associated with a quake in the Cascadia subduction zone, an offshore undersea fault.
The study said the regional impact could be on par with Japan’s 2011 earthquake, tsunami and nuclear disaster that devastated a wide swath of Honshu’s Pacific coastline and killed nearly 20,000 people.
Because a quake would make car travel mostly impossible, the study focuses on walking people to safety, or higher ground.
In the coastal Washington cities of Aberdeen and Hoquiam, about 90 percent of the 20,000 residents could have enough time to evacuate if they walked to safety at a minimum of 2.2 mph, Wood said. That percentage rises to 99 percent if they move faster, and know where to go, he said.
The study found the most people in coastal communities should have sufficient time to evacuate, and that high ground is reachable if people are aware of the threat and practice their routes.
A small percentage of people who live too far from high ground would need tall, specially constructed structures to withstand the quake and tsunami, it said.
(Reuters)
