Tsunami Escape - Washington's Uphill Battle

Thirty to sixty-foot tsunami waves reach outer beaches within 10 to 20 minutes of 9.0 quake.
This short documentary explores how coastal communities along Washington's outer coast are preparing for an eventual earthquake and tsunami emanating from the Cascadia Subduction Zone fault. About 70 miles off Washington’s outer coast at the bottom of the Pacific Ocean, the boundary between tectonic plates is in the loading phase of a destructive cycle. Pressure has been building up for more than three hundred years.
The Cascadia Subduction Zone is a megathrust fault stretching several hundred miles from Vancouver Island, Canada to Northern California.
It's a locked tectonic boundary where the Juan de Fuca plate collides with the North American plate. The denser oceanic plate is being forced down and spongier rock at the edge of the continental plate is being compressed like a spring.
The ground above is rising. All of coastal Washington and Oregon, and part of Northern California are at risk of a cataclysmic natural disaster because of the CSZ.
At some point the continental plate will snap back into its former position. At that moment, the land on Washington’s outer coast could drop by several feet and jump several feet to the west.
All of Western Washington will be subjected to several minutes of violent shaking. The sudden uplift on the seafloor will send tsunami waves hurtling outward in every direction at the speed of a commercial jet. The waves slow down and pile up as they reach the shore crashing inland with debris filled water capable of scouring buildings down to their foundations.
Towering tsunami waves reaching 30 to 60 feet in height are projected to reach the outermost beaches within 10 to 20 minutes of the shaking.
High ground is too far from many popular Pacific Northwest beaches for people to make it to safety before the waves arrive.
Chief Hazards Geologist Corina Allen with the Washington State Department of Natural Resources explains tsunami inundation models and what coastal communities around the Olympic Peninsula can expect in the event of a full rupture of the Cascadia fault.
“In these coastal communities, particularly the low-lying communities like Long Beach or Ocean Shores, the tsunami inundation, which is the amount of flooding over previously dry land, can be up to 60 feet in some locations,” said Allen. “Vertical evacuation structures are really the only hope to save the number of people that are on these peninsulas in some of these high risk communities.”
The documentary features stunning images from the 2011 Tohoku earthquake and tsunami in Japan, the 2001 Nisqually earthquake in Washington state, and the 1964 Great Alaskan Earthquake as well as extensive aerial and ground level footage of the Washington state coast line. There’s even underwater video of the Cascadia fault itself from the early 1980’s.
You’ll hear about the overwhelming amount of work needed to make the northwest coast more resilient, the challenges and of building vertical evacuation structures and the tradeoffs for beach towns with small budgets.
It also explores the history of megathrust earthquakes and tsunamis in the Pacific Northwest.
USGS Scientist emeritus and Affiliate professor at the University of Washington, Brian Atwater, retraces his steps in uncovering the significance of ghost forests in the Pacific Northwest and the evidence of major Cascadia tsunamis in the past.
Quinault Indian Nation President Guy Capoeman relates the Quinault tribe’s long-term plan to move buildings and houses to higher ground and the oral traditions that may be linked to ancient Cascadia megaquakes.
The Washington’s Military Department’s Emergency Management Division Director Robert Ezelle describes why he believes a magnitude 9 or greater earthquake and tsunami from the Cascadia Subduction Zone would be the worst natural disaster in the history of the United States.
“It will dwarf Katrina, Sandy, and a number of other large disasters combined. It’ll be absolutely the largest thing that we will have had to have dealt with in our country and it’s not a matter of if we have to deal with it, it’s a matter of when,” said Ezelle. “People need to be prepared to be a month, two months, on their own.”
“Tsunami Escape” highlights how DNR and EMD have been working to raise awareness about the threats and assist local governments in planning vertical evacuation structure construction.
Long Beach City Administrator David Glasson explains what happened with their early plans to develop a vertical evacuation berm.
Shoalwater Bay Indian Tribe Emergency Management Director Ken Ufkin describes the process of building what will be only the second purpose built tsunami vertical evacuation structure in the state.
(Traditional music courtesy of Quinault Indian Nation President Guy Capoeman)
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