Propagation across the open ocean onto the continental shelf of Australia of tsunami waveforms generated by submarine earthquakes has been modelled using a coarse-grid depth-averaged hydrodynamic-numeric model. The initial conditions require the specification of the seafloor displacement field, which is determined analytically using the seismic parameters of the fault which generated the tsunami.
Focussing mechanisms are evident as the waveform propagation responds to bathymetric features. Near the land boundary, emphasis is upon the envelope of tsunami amplitudes and arrival times, which are compared with tide gauge data where available.
This model has been developed with a view to identify the areas of the Australian coast most vulnerable to tsunami damage due to seismic activity in the Indonesian region and large earthquakes south of Australia. The next phase of this project involves linking this model to a fine-grid coastal-sea model to simulate runup and inundation.
