Nested and multi-physics modeling of tsunami evolution from generation to inundation

This paper aims to introduce non-dispersive shallow water and dispersive, Boussinesq-type numerical models used in tsunami modeling, as well as an approach to two-way couple these models together. The fundamental purpose of the coupling effort is to develop the capability to seamlessly model tsunami evolution from generation to inundation with fine scale resolution, without the loss of locally important physics. The two model components are briefly introduced, and the physical mismatch between the two models is examined analytically. As coupling of numerically and physically heterogeneous models may result in undesirable errors, a general benchmark test has been undertaken to provide a parameter range for expected accuracy and stability. Long wave propagation onto a shallow shelf is simulated to validate the coupled model, examining the importance of dispersive and nonlinear effects in the nearshore area, as well as the utility of the coupled modeling system. Finally, the model is applied to the 2004 Indian Ocean tsunami. In this test, the local dynamics experienced in the Port of Salalah in Oman, as documented by Okal et al. (2006), are recreated.

► A Boussinesq model has been two-way coupled with a shallow water wave equation model.
► Resolution of local, small-scale (O(1 m)) effects imbedded in an ocean-basin-scale domain.
► Simulation of the 2004 Indian Ocean tsunami with grids lengths ranging from 10 m to 5 km.
► Recreation of eddies in Salalah Port responsible for breaking of ship’s mooring lines.