FY 1998

Cascadia subduction zone tsunamis: Hazard mapping at Yaquina Bay, Oregon

Priest, G.R., E. Myers, A.M. Baptista, P. Fleuck, K. Wang, R.A. Kamphaus, and C.D. Peterson

Open-File Report O-97-34, Department of Geology and Mineral Industries, State of Oregon, 144 pp (1997)

Potential tsunami flooding from Cascadia subduction zone earthquakes at Yaquina Bay in Newport, Oregon was explored by simulating fault ruptures and resulting tsunamis. Flooding from most scenario tsunamis is modest, because of protection by large jetties and sand dunes. However, a worst case tsunami reaches elevations of 35 feet at the open coast and floods all lowlands 1.5 miles inland. Flooding from scenario tsunamis reaching elevations of 12 and 27 feet at the open coast was also mapped to illustrate the range of uncertainty in the mapping technique. Current velocities in the main shipping channel were up to 16 knots.