TSUNAMI DISPERSION SENSITIVITY TO SEISMIC SOURCE PARAMETERS

The study focuses on the sensitivity of frequency dispersion effects to the form of initial surface elevation of seismic tsunami source. We vary such parameters of the source as rupture depth, dip-angle and rake-angle. Some variations in magnitude and strike angle are considered. The fully nonlinear dispersive model on a rotating sphere is used for wave propagation simulations. The main feature of the algorithm is the splitting of initial system on two subproblems of elliptic and hyperbolic type, which allows implementation of well-suitable numerical methods for them. The dispersive effects are estimated through differences between computations with the dispersive and nondispersive models. We consider an idealized test with a constant depth, a model basin for near-field tsunami simulations and a realistic scenario. Our computations show that the dispersion effects are strongly sensitive to the rupture depth and the dip-angle variations. Waves generated by sources with lager magnitude may be even more affected by dispersion.