Cascadia's Fault - Jerry Thompson [134]
I gave my stopwatch to Patrick Corcoran, who strapped it on his wrist and got ready to run. He stood only a few steps away from the wide, sandy beach at the base of the Lewis and Clark statue in the traffic circle at the western terminus of Broadway, the main drag in Seaside, Oregon. Young and fit, probably in his late thirties, Corcoran is a surfer by choice and an employee of Oregon State University by profession. As a “hazards outreach” specialist, he helps people along the coast plan for and come to terms with some of the realities of life on the edge—things like major winter storms, and getting ready for “the Big One” from Cascadia’s fault.
Corcoran is demonstrating the official evacuation route, which begins at the beach promenade and follows Broadway, the main east–west business corridor, all the way across the downtown core to higher ground on the east side of town. As I give Corcoran the nod, he clicks the stopwatch and starts running.
In a real emergency, running or walking would probably be the only way to get out of town fast. Previous experience with tsunami false alarms in Seaside had already taught local residents that vehicle traffic hits gridlock almost immediately. It was a busy summer day so the sidewalk was crowded with shoppers and tourists out for a stroll. Corcoran jogged at a brisk pace, zigzagging through the throng.
The Pacific coastline here runs almost exactly north–south, so to get away from the ocean on the west side you have to move toward the first rank of low hills in the Coast Range mountains on the east. The city of Seaside is built on the wide, flat delta of the Necanicum River, so anyone trying to outrun a tsunami would have to hustle to get across the two bridges that span branches of the river, hoping the earthquake and the incoming tsunami had not already knocked the concrete decks off their pilings.
By the time Corcoran got past the river and started uphill on a winding switchback road, he was breaking a sweat and breathing hard. He had covered more than twenty city blocks without gaining any altitude. Now the road started to climb steeply. He already knew from studying the map contours exactly which house he had to reach in order to get himself at least fifty feet (15 m) above sea level and presumably beyond the reach of the biggest waves likely to come from Cascadia’s subduction zone.
When he crossed the imaginary finish line, he stopped and clicked the watch again. “So, seven minutes and thirty-three seconds,” he huffed. “Not too bad, but it was a hard run.” On a nice sunny day under ideal conditions, he certainly would have made it to high ground in plenty of time. But what if the earthquake happened on a stormy winter’s night? Powerlines and trees would be down and all kinds of obstacles would be in the way.
And what about those not as young or physically fit as Patrick Corcoran? The likelihood that the vast majority of people could make that run before the first tsunami surge hit the beach seemed pretty slim to me. For those who hung around to watch the incoming waves, mesmerized by the spectacle as so many were on the beaches of Sumatra and Thailand, the chances of survival would be even less.
Corcoran has a set of simple guidelines he explains to anyone who will listen. Rule number one: if you’re anywhere near the coast in a subduction zone and you feel the earth begin to shake, start moving to higher ground as soon as the shaking stops, or sooner if you can. Rule number two: if you’re living in or visiting a coastal earthquake zone you should already know where the high, safe ground is and how to get there. Grab a map, study the evacuation routes, and always have a sense of where you are. Rule number three: don’t wait for a warning siren because there probably won’t be one. Your only warning will be the violent shaking of the ground, so don’t wait for