Numerical modeling of a potential landslide-generated tsunami in the southern Strait of Georgia

Abstract We report results of numerical simulations a potential subaerial landslide on the coast Orcas Island and resultant tsunami waves in southern Strait Georgia near US/Canada border. A likely trigger is strong ground shaking during large earthquakes nearby Holocene active Skipjack fault zone. For worst-case scenario, we assume 0.17 $${\textrm{km}}^3$$ km 3 rigid failure steep northeast island, spanning $$\sim$$ ∼ 5 km between previous deposits adjacent seafloor. The motion resulting generation are modeled using three-dimensional (3D) non-hydrostatics physics-based NHWAVE model. simulated moves downslope with peak velocity 13.64ṁ/s travels 732 m before coming to rest after 85 s 75-m water depth. Tsunami propagation then continued 2D fully nonlinear dispersive Boussinesq wave model FUNWAVE-TVD succession layered nested grids. modeling reveals susceptible locations, particularly as will arrive little or no warning. In near-source region, have amplitudes 15–20 m, current speeds up 10 m/s, runup 30 m. Smaller, but significant, occur throughout region surrounding Island. direction, reaches 7.5 at Neptune Beach Lummi Bay. Both initial reflected cause significant (> 1.5 m) along much shoreline Point Roberts