Due to unforeseen circumstances the originally scheduled talk by Professor Brandon Johnson has been cancelled and replaced with the following seminar.

Theoretical and Computational Contributions to the Modeling of Global Tsunamis

The distribution of tsunami amplitudes in the open ocean is controlled by source mechanism as well as bathymetry geometry and resolution, with the latter controlling far-field tsunami features. However, large detailed bathymetry grids result in long computer simulation times for tsunamis. It is therefore of interest to investigate the amount of physical detail in bathymetric grids that control the most important features in tsunami amplitudes, to assess what constitutes sufficient level for grids in numerical simulations. By decomposing the Pacific bathymetry using a spherical harmonics approach one can create “smoothed” versions of the original field. Using these simplified bathymetries to simulate tsunamis from potential ruptures around the Pacific, we can see that for large megathrust events (M0=1029 dyn-cm), only a resolution of ~1000 km (equivalent to l=40), or ~1% surface smoothness of the Pacific is needed in order to reproduce the main components of the true distribution of tsunami amplitudes. This would result in simpler simulations, and faster computations in the context of tsunami warning algorithms.

In a separate context, an overview of tsunami studies and a report on a study of a meteotsunami are presented. These scenarios are evidence for the fact that tsunami studies are interdisciplinary fields of research that require coordinated efforts by investigators from various backgrounds.

MICDE is co-hosting this seminar with the Earth and Environmental Sciences department.