Numerical modeling of tsunami propagation over varying water depth

Abstract

A dispersion-correction finite difference numerical scheme is employed to simulate the propagation of distant tsunamis over slowly varying topography with improved dispersion effect of waves. The scheme solves the shallow-water equations on a uniform grid system. However, the actual computation is made on an imaginary grid system whose grid size is adjustable according to the condition required to satisfy local dispersion relationships. The present model is applied to the simulation of a historical tsunami event. Numerical results are compared with the tide gage records, and reasonably good agreements are obtained.