Intercomparison of hydrostatic and nonhydrostatic modeling for tsunami inundation mapping

Nonhydrostatic modeling has emerged as an effective tool for seismological and tsunami research over a decade, but its general application in hazard mapping engineering design remains topic of discussion. The approach incorporates the depth-averaged vertical velocity nonhydrostatic pressure nonlinear shallow-water equations that provide Poisson-type equation via conservation mass quasi-three-dimensional flows. After 2011 Tohoku tsunami, State Hawaii augmented existing inundation maps to account probable maximum tsunamis from Mw 9.3 9.6 Aleutian earthquakes. use both hydrostatic with common set telescopic computational grids covering 1330 km shorelines facilitates thorough intercomparison under distinct extreme events range tropical island terrain bathymetry. Including flow dynamics can enhance formation slowly attenuating trough behind leading crest across ocean well drawdown receding water steep nearshore slopes. consistently gives lower predictions offshore amplitude due frequency dispersion produce more severe coastal surges resonance insular slopes trapping waves by wide shelves. Despite potential underestimating surges, lack inertia models result substantially larger runup terrain. processes are complex strong dependence on waveform topography be elucidated approach.