Cascadia's Fault: The Coming Earthquake and Tsunami That Could Devastate North America

Jerry Thompson


“I live here. And every time I drive to the coast, I see towns that are not long from now going to be under water from the next tsunami…The Cascadia Subduction Zone earthquake and the tsunami that’ll come with it will be virtually identical to the one in 2004 in Sumatra. It’ll dwarf 1906 (San Francisco). And Katrina. It’ll be many dozens of Katrinas all at once. Coastal towns from northern California to Canada will be virtually wiped out…It’s a little hard to go to the beach and just hang out there and enjoy it.”

Chris Goldfinger, marine geologist at Oregon State University, from Cascadia’s Fault


Waiting for the Next Big Thing

On Good Friday, 1964, the Alaskan earthquake caused extensive damage over 50,000 miles. An area the size of Washington and Oregon suddenly heaved up, lifting the sea floor 50 feet and displacing so much water as to create the tsunami that reached as far south as Crescent City, California, where more than a dozen people were killed.

The 9.2 magnitude earthquake, one of the largest in recorded history, was also significant for what it taught scientists about this dynamic planet we precariously inhabit. With each subsequent major seismic event, scientists have been steadily learning more about the fiery, grinding mechanisms that result in earthquakes and the deadly tsunamis they often generate.

Jerry Thompson, a documentary film producer for the Canadian Broadcasting Corporation, has been following the scientists’ work for decades, with a particular focus on the Cascadia Subduction Zone. Living on the coast of British Columbia, Thompson has more than an academic interest. Beneath him (and us) the Juan de Fuca plate is sliding east under the westward-moving North America plate. The anticipated mega-earthquake and resulting tsunami is expected to wipe out entire communities along the northwest coast, to shock, rock, and destroy or extensively damage the infrastructures of Vancouver, BC, Seattle, Tacoma, and Portland, and kill hundreds of thousands of people.

But if you can just get past the idea of catastrophic death and destruction, this is a fascinating tale of geologists acting as major sleuths in uncovering one of the earth’s deepest mysteries. The rather fantastical 19th century idea of Continental Drift matured into the 20th century theory we know today as plate tectonics, where not really “continents” but huge plates are shifting and moving over the earth as the planet continues to expand from its internal heating.

Thompson discusses developments in monitoring the plates’ movements to help warn of impending disaster. Electronic equipment now “listens” to the continual grinding of the plates (“When all the normal rumble and grind along a big subduction zone mysteriously goes quiet, watch out—something’s bound to happen.”)

He also reviews measures that coastal communities are taking, such as “vertical evacuation shelters” and coastal sirens (You have fifteen minutes—so please don’t dawdle,) and considers lessons learned from recent major quakes and tsunamis, such as the 2011 Fukushima disaster: Probably not a good idea to build nuclear reactors on active fault lines.

He writes without being sensationalistic—he doesn’t need to be—but in the final chapter, he paints a chilling hour-by-hour scenario of what scientists expect will happen maybe this year…or in the next fifty years. Or maybe the next hundred years (Sorry we can’t be more precise.) Oh, and you probably shouldn’t bother buying more insurance: “Before the day is done seven of the world’s largest insurance companies file for bankruptcy. There’s absolutely no way they can pay all the claims.”

Stay tuned for updates.


This review first appeared in The Columbia River Reader (May 15-June 15, 2020.) Reprinted with permission.