Puget Sound's Risk for a Haiti-Like Earthquake

You've probably spent a lot of time the past week watching video and photos, reading news articles and tweets about the Haiti earthquake. You've felt sorry for the Haitians, aghast at the scenes of death and ruin, and agonized over the condition of the survivors. But you probably haven't imagined anything remotely similar happening in the Seattle area.

Back in June 2005, a half year after the earthquake and tsunami in Southeast Asia, and over four years after the Nisqually earthquake, the Earthquake Engineering Research Institute and the Washington Military Department brought out a "Scenario for a Magnitude 6.7 Earthquake on the Seattle Fault."

That is, an earthquake slightly lighter than what struck Haiti last week, and one that would come on the Seattle Fault, which runs through south Seattle, Mercer Island, Bellevue, and the Issaquah area. It wasn't pretty: the vision of the aftermath of a 14-mile surface rupture running roughly parallel to I-90 involved over 1,600 dead, another 24,000 wounded, $33 billion of damage, and months of transportation problems for Puget Sound.

The scenario said a 6.7 Seattle Fault quake will cause damage "far worse and more extensive than seen in any earthquake in the state's history."

"The viaduct will be heavily damaged or collapse," in a way very similar to how Oakland's Cypress Viaduct pancaked in the Loma Prieta quake, Boeing Field "will experience significant liquefaction" on its runways and close for several days, the Seattle ferry terminals "will shut down for at least a week due to damage from ground failures and failure of the seawall," and we'll see a lot of the brick buildings in Pioneer Square tumble, along with a lot of the concrete warehouses south of downtown.

The field hospitals being set up in Haiti will appear here, as various hospital buildings shut down from quake damage. We'll have similar trouble getting water, gas, sewage, and other utilities to start working again, because the quake will crack pipes, splinter power lines, and shut down cell phone service. Those sturdy old brick schools in Seattle and elsewhere? Some, at least, will crumble.

I could go on for some time detailing the wheres and whats of how the 1,600 will die in the envisioned 6.7 quake, as well as the many problems faced by its survivors. But if you're not an emergency planner or a seismologist, what it all comes to is: Don't just feel sorry for the Haitians. We could be the next object of pity, so we'd better get ready. Learn from the disaster in Haiti, don't just look at it.

You can learn about Puget Sound earthquake hazards-the Seattle Fault Scenario's just one of three basic quake types threatening the region-by visiting the Cascadia Region Earthquake Workgroup, the Pacific Northwest Seismic Network, and by reading through the "Scenario for a Magnitude 6.7 Earthquake on the Seattle Fault." And if you want some context for the region's earthquake hazards, take a look at my project chronicling the many sizable historic Northwest quakes from the massive Cascadia Subduction Zone quake of 1700 to the Nisqually quake in 2001.