This tool was created based on results from research on the effects of Cascadia Subduction Zone (CSZ) on the response of bridges conducted by Portland State University with support funding from the Oregon Department of Transportation. Oral traditions of people native to the Pacific Northwest and lots of scientific data point clearly to a major earthquake along the Cascadia Subduction Zone in 1700, and another one is looming. — The Cascadia Subduction Zone earthquake gets headlines around the Pacific Northwest, but geologists say the next big earthquake you feel will likely come from a fault somewhere else. 4-25), and deep zone of stable sliding extending beneath the volcanic arc. The Cascadia Subduction Zone is a 620-mile-long fault that stretches from British Columbia to Northern California, and pressure is building daily. Other times, a smaller segment of the faultline ruptures, resulting in a magnitude 8. Officials simulate their response to a Cascadia Subduction Zone earthquake at the Emergency Operations Center in Southeast Portland. The Cascadia Subduction Zone is a more than 600-mile fault located 70-100 miles off the West coast of North America. The most recent big Cascadia earthquake occurred on January 26, 1700, dated by accounts from Japan of an orphan tsunami generated by a Cascadia earthquake and recorded after the wave crossed the Pacific Ocean. In the event of a Cascadia Subduction Zone earthquake, over 200,000 homes are likely to be damaged in the city of Portland, according to a study by the Oregon Department of Geology and Mineral Industries (DOGAMI). The Cascadia Subduction Zone has remained locked, loaded, and quiet despite all this tumult elsewhere in the world. Though it produced a few small earthquakes within the “locked zone”, none of the larger earthquakes so prevalent in other subduction zones around the world have happened here. Earthquakes on the Cascadia Subduction Zone have struck the Northwest offshore for at least 10,000 years. Cascadia Subduction Interface The most threatening earthquakes in Cascadia are those associated with the Cascadia subduction zone, which is the tectonic plate boundary between the subducting oceanic Juan de Fuca, Gorda, and Explorer Plates and the over-riding continental North America Plate. Fig. The research team was led by Dr. Peter Dusicka and this tool is the result of work from research assistants Ramiro Bazaez, Zakary Hoyt and Mario Zavalas. The two largest cities in the Pacific Northwest, Seattle and Portland, are home to several million people.