One of the worst nightmares for many Pacific Northwest residents is a huge earthquake along the offshore Cascadia Subduction Zone, which would unleash damaging and likely deadly shaking in coastal Washington, Oregon, British Columbia and northern California. The last time this happened was in 1700, before seismic instruments were around to record the event. So what will happen when it ruptures next is largely unknown. A University of Washington research project, to be presented October 24 at the Geological Society of America’s annual meeting in Seattle, simulates 50 different ways that a magnitude-

9.0 earthquake on the Cascadia subduction zone could unfold. “There had been just a handful of detailed simulations of a magnitude-9 Cascadia earthquake, and it was hard to know if they were showing the full range,” said Erin Wirth, who led the project as a UW postdoctoral researcher in Earth and space sciences. “With just a few simulations you didn’t know if you were seeing a best-case, a worst-case or an average scenario. This project has really allowed us to be more confident in saying that we’re seeing the full range of possibilities.” READ MORE