Welcome to Portland--Sitting on the Big One

Abstract

Welcome Seismological Society of America meeting attendees to Portland, Oregon, my hometown! Home of clear blue skies (when it's not raining), the beautiful Willamette (Wil-LAM-ette) and Columbia rivers, creeks and lakes galore, majestic volcanic peaks (look to the north and east if it's a clear day), green trees, trees, and more trees, delicious pinot noirs, and of course, gigantic earthquakes. Not just big earthquakes but gigantic earthquakes, like magnitude ( M ) 9! Trouble is, hardly anyone knows about it. Well, that's not exactly true. A good number of Portlanders, Oregonians, and Pacific Northwesterners know that earthquakes can occur in this corner of the country, but unfortunately the majority of people rarely think about these lurking hazards and certainly have not prepared for them. The biggest and baddest earthquake sits on the doorstep of the Pacific Northwest, or more specifically beneath our beautiful coastline along the Cascadia subduction zone megathrust between the overlying North America plate and the down-going Juan de Fuca plate. The biggest and baddest earthquake sits on the doorstep of the Pacific Northwest, or more specifically beneath our beautiful coastline along the Cascadia subduction zone megathrust between the overlying North America plate and the down-going Juan de Fuca plate. Yet thousands of high-risk buildings such as unreinforced masonry (URM), tilt-up, preseismic code steel-frame, and vulnerable transportation structures still stand, ready to be damaged or to collapse when the next giant megathrust earthquake strikes. It's been more than three centuries since the last M 9 shook the Pacific Northwest in 1700. The event generated a tsunami that swept over the beaches of northern California, Oregon, Washington, southern British Colombia, and even Japan. A repeat of such an event could result in thousands of deaths, particularly along the coastline, with significant damage to infrastructure as far inland as the Willamette Valley …