Sumatra 2004. Chile 2010. New Zealand and Japan 2011.
British Columbia… tomorrow?
The Cascadia Subduction Zone is a crack in the earth’s crust roughly one hundred kilometres offshore extending from northern Vancouver Island to the Redwood Coast of California. A segment of the infamous Pacific “Ring of Fire,” the Cascadia fault is virtually identical to the tectonic time bombs that decimated Sumatra in 2004, Chile in 2010, and Japan in 2011. And yet for years conventional wisdom held that Cascadia was not a significant seismic threat—because no major earthquake had occurred there “in all of recorded history.”
This book tells the tale of scientific sleuthing that uncovered convincing evidence that Cascadia is indeed an active and very dangerous fault. From stories told by the elders of coastal tribes, to stories of “an orphan tsunami” that struck Japan in 1700, to “a ghost forest” of cedars drowned on the Washington coast, to GPS tracking data that confirmed the uplift, buckling and horizontal movement of entire coastal mountain ranges—scientists with muddy boots solved the mystery of Cascadia’s Fault.
A “full margin rupture” of the Cascadia fault can and will generate the same kind of earthquake that hit Japan in March 2011—at magnitude 9 or higher. Scientists now know there have been 43 Cascadia quakes in the last 10,000 years. Statistically there is a 30 percent chance a Cascadia quake will happen within the next fifty years. It could happen tonight.
Unlike quakes on the San Andreas that ravage one city or region at a time (either San Francisco or Los Angeles…) shockwaves from Cascadia will slam five cities at once—Vancouver, Victoria, Seattle, Portland, and Sacramento—and will wreck dozens of smaller towns and coastal villages in between. Tsunami waves will hit the beaches of the West Coast as well as Alaska, Hawaii, Japan, Indonesia, Hong Kong, the Philippines, Australia, and New Zealand. One scientist suggested a Cascadia quake will be like five Hurricane Katrinas at the same time.
Contrary to first impressions, however, this book in not about doom and gloom. Its underlying message is that the vast majority of people living in Cascadia’s multiple danger zones will survive the coming jolt. The key issue is how well they endure the aftermath. And that depends entirely on how much time and attention they invest now in preparing and making their communities resilient.