Open-File Report O-08-12, Prehistoric Cascadia Tsunami Inundation and Runup at Cannon Beach, Clatsop County, Oregon.
One of the most important tasks for the Oregon Department of Geology is helping coastal communities understand and mitigate for the risk of possible tsunamis. Communities located in exposed, low-lying areas along the Oregon coast face the risk of inundation by tsunamis produced by earthquakes around the Pacific Rim far from Oregon, as well as local earthquakes on the Cascadia subduction zone.
As part of this important effort, DOGAMI is remapping the state’s entire 362-mile long coastline for tsunami inundation using state-of-the-art computer models, coupled with laser based terrain mapping and field based geologic investigations. This report by Dr. Rob Witter of DOGAMI, discusses field investigations conducted over the past 2 years that detail the landward extent of sand deposits left by Cascadia tsunamis that inundated the lower Ecola Creek valley in Cannon Beach over the last 2,000 years. 2008
by Rob Witter