Mapping Tsunami Inundation for the U.S. East Coast

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By contrast with the long history of tsunami hazard assessment on the US West coast and Hawaii, tsunami hazard assessment along the eastern US coastline is still in its infancy, in part due to the lack of historical tsunami records and the uncertainty regarding the magnitude and return periods of potential large-scale events (e.g., transoceanic tsunamis caused by a large Lisbon 1755 type earthquake in the Azores-Gibraltar convergence zone, a large earthquake in the Caribbean subduction zone in the Puerto Rico (PR) trench or near Leeward Islands, or a flank collapse of the Cumbre Vieja Volcano (CVV) in the Canary Islands). Moreover, considerable geologic and some historical evidence (e.g., the 1929 Grand Bank landslide tsunami, Currituck slide site off NJ) suggests that the most significant tsunami hazard in this region may arise from Submarine Mass Failures (SMF) triggered on the continental slope by moderate seismic activity (as low as Mw = 6 to the maximum expected in the region Mw = 7.5); such tsunamigenic landslides can potentially cause concentrated coastal damage affecting specific communities.

This project will assess tsunami hazard from the above mentioned and other relevant tsunami sources recently studied in the literature and model the corresponding tsunami inundation in affected US East coast communities. We will combine ocean scale simulations of transoceanic tsunami sources, such as Lisbon 1755 like or Puerto Rico Trench co-seismic events, and CVV collapse, with regional scale simulations of these events, along with the regional scale SMF events, in order to establish the relative degree of hazards for East Coast communities. Detailed inundation studies will be conducted for highest-risk East Coast communities, and results of these studies will be used to construct a first-generation of tsunami inundation maps for the chosen communities.

The primary role of DGS is create relevant flood inundation maps appropriate for both the public and emergency management personnel, pertaining to modeled runs of tsunami waves off the mid-Atlantic coast. Initially, the relevant areas are from central/southern New Jersey to the southern point of the Delmarva peninsula. Relevant high resolution lidar and basemap datasets will be collected and stored, with modeled run data mapped at various scales and time intervals. Particularly, maps of peak infiltration of waves onto the coastal areas under set conditions are a primary product.

This project is being done in collaboration with the Center for Applied Coastal Research, University of Delaware, and the Department of Ocean Engineering, University of Rhode Island. Funding is from the NOAA National Tsunami Hazard Mitigation Program (NTHMP).