Portland is probably similarly affected by the subduction zone, but the inland fault system is not as active as in Seattle. Nonetheless, there is a fault that i

Portland is probably similarly affected by the subduction zone, but the inland fault system is not as active as in Seattle. Nonetheless, there is a fault that is underneath the Portland Hills that could do some damage to the city. The seismic risk faced by a city or an individual is really the product of the hazard (formally, the probability of a certain level of ground shaking) and the response of the building stock or other infrastructure. Fortunately, both cities have a large amount of wood-framed housing, which performs quite well in earthquakes (as do modern apartment buildings). However there are a lot of old masonry buildings used for schools, offices, etc. If these aren't properly reinforced, they can be deadly, not only because they are fragile but because they are heavy when they do collapse. But if you live in and work in a modern structure or an old wooden one, you'll probably make it through alright, as long as you have some food and water at home. The big concern in both cities is actually liquefaction, where some water-saturated soils lose their strength during an earthquake. In both cities, there is some amount of housing stock built on liquefiable soils, but there is a huge amount of commercial and industrial building stock built out on fill dirt on the respective waterfronts (which is where the old masonry buildings are as well). One of the scariests scenarios is the Critical Energy Infrastructure in NW Portland, where massive amounts of oil are in the huge tanks built on fill into the Willamette, liquefying and then spilling into the Willamette/Columbia: https://www.multco.us/sustainability/cei-hub-seismic-risk-analysis https://www.multco.us/sustainability/cei-hub-seismic-risk-an...