FY 1993

Modeling tsunami flooding of Crescent City

Mader, C.L., and E.N. Bernard

In Tsunami '93, Proceedings of the IUGG/IOC International Tsunami Symposium, Wakayama, Japan, 23–27 August 1993, 321–326 (1993)

The generation, propagation and interaction of tsunami waves with Crescent City, California is being numerically modeled for specific historical events. The modeling is performed using the SWAN code which solves the nonlinear long wave equations. The March 28, 1964 tsunami was caused by an Alaskan earthquake. The tsunami generation and propagation across the Pacific was modeled using a 20 minute grid for the North Pacific. The wave arriving in the region of the U.S. west coast was modeled using a 5 minute grid. The wave arriving outside of Crescent City harbor was then modeled using a 25 meter grid of the harbor and town. The model gives approximately the observed maximum area of flooding of Crescent City. The large amount of flooding of Hilo, Hawaii from the 7.6 magnitude 1946 Alaskan earthquake and small amount of flooding from the 8.4 magnitude 1964 Alaskan earthquake at Hilo while extensively flooding Crescent City was reproduced by the numerical model. The effect of the tide was modeled and found to be small.