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Abstract

On January 9, 2014 a M=5.1 earthquake occurred on the north shore of Cuba. The event was dip-slip on a WNW-ESE fault. The location is the site of offshore islands, oriented WNW-ESE, with a total length of 200 km. This suggests that larger seismic events are possible. The earthquakes are 90 miles (144 km) from the south shore of Florida. We modeled potential tsunamis from a fault oriented WNW-ESE and dipping 90 degrees. To represent shaking from a M=7.5 earthquake we used a length of 100 km, width 10 km, and slip 1.85 m. The modeling was performed using a numerical program (Nicolsky et al., 2011) at UAFGI. Results show heights of 3-8 cm at Key West, Everglades (ENP), Marco Island and Miami. Maximum heights of 0.4 m are observed near source. Travel times for initial wave are: ENP 15 min; Key West 28 min; Miami 30 min; Marco Island 240 min. The peak occurs 10-50 min later. We also modeled slip with reversed polarity (some aftershocks showed reverse slip); the models gave the same heights and times but reversed polarity. This is because the grid for bathymetry is coarse (3x3.7 km pixel size) so detailed interaction with the shore is not well represented. We modeled a larger event by increasing the slip. This resulted in a M=7.8 hypothetical event, with higher amplitudes but similar time histories. These results suggest that South Florida would experience only a modest hazard from tsunamis generated by earthquakes on the north shore of Cuba.