The Big-Shake, Big-Wave Theory
If a megaquake like the one that hit Japan last March were to strike the U.S., the Pacific Northwest coast would be the likeliest spot. Geologists have their eyes on the Cascadia subduction zone, a 740-mile seam where the Juan de Fuca and North American plates meet. The CSZ has been building up tension for more than 300 years, say some seismologists. If that te
A. MINUTE 0:00. The North American plate slides 57 feet west over the heavier Juan de Fuca plate, which moves east about an inch per year. The quake’s initial pressure wave travels through the Earth’s crust at 13,000 miles per hour and reaches the Northwest coast in ten seconds.
Totally Psyched for the Full-Rip Nine
Join us on a footnoted foray into the terrifying world of megaquakes, tidal waves, and the fine art of being your own Jesus.
B. MINUTE 0:00. Displaced water creates a low standing wave, which peels off in two directions. One wave heads toward Japan at 450 miles per hour, reaching Honshu in ten hours. The other will reach the Northwest coast in 20 minutes.
C. MINUTE 3:00. The Northwest coast drops five feet
D. MINUTE 5:00. The earthquake stops. The tsunami is now 35 miles offshore.
E. MINUTE 10:00. The wave is 15 miles offshore. Water at the coast has begun to recede.
F. MINUTE 20:00. The edge of the tsunami hits the coast at flash-flood speed, about 30 mph, and then slows to 11 mph on dry land. The water will rise to 30 feet in places and proceed as far as six miles inland.
Lead Photo: Illustration by Emily Cooper
Our mission to inspire readers to get outside has never been more critical. In recent years, Outside Online has reported on groundbreaking research linking time in nature to improved mental and physical health, and we’ve kept you informed about the unprecedented threats to America’s public lands. Our rigorous coverage helps spark important debates about wellness and travel and adventure, and it provides readers an accessible gateway to new outdoor passions. Time outside is essential—and we can help you make the most of it. Making a financial contribution to Outside Online only takes a few minutes and will ensure we can continue supplying the trailblazing, informative journalism that readers like you depend on. We hope you’ll support us. Thank you.
Contribute to Outside →