A fast global tsunami modeling suite as a trans-oceanic tsunami hazard prediction and mitigation tool

Abstract:

The past decade has been witness to two mega-tsunami events, 2004 Indian ocean tsunami and 2011 Japan tsunami and multiple major tsunami events; 2006 Java, Kuril Islands, 2007 Solomon Islands, 2009 Samoa and 2010 Chile, to name a few. These events generated both local and far field tsunami inundations with runup ranging from a few meters to around 40 m in the coastal impact regions. With a majority of the coastal population at risk, there is need for a sophisticated outlook towards catastrophe risk estimation and a quick mitigation response. At the same time tools and information are needed to aid advanced tsunami hazard prediction. There is an increased need for insurers, reinsurers and Federal hazard management agencies to quantify coastal inundations and vulnerability of coastal habitat to tsunami inundations. A novel tool is developed to model local and far-field tsunami generation, propagation and inundation to estimate tsunami hazards. The tool is a combination of the NOAA MOST propagation database and an efficient and fast GPU (Graphical Processing Unit)-based non-linear shallow water wave model solver. The tsunamigenic seismic sources are mapped on to the NOAA unit source distribution along subduction zones in the ocean basin. Slip models are defined for tsunamigenic seismic sources through a slip distribution on the unit sources while maintaining limits of fault areas. A GPU based finite volume solver is used to simulate non-linear shallow water wave propagation, inundation and runup. Deformation on the unit sources provide initial conditions for modeling local impacts, while the wave history from propagation database provides boundary conditions for far field impacts. The modeling suite provides good agreement with basins for basin wide tsunami propagation to validate local and far field tsunami inundations.