Nicaragua outer-rise earthquake characteristics were defined by the analysis of the oceanic lithosphere characteristics and the local seismicity, considering INETER and CMT catalogs; establishing a distance range of occurrence for the outer-rise earthquakes, a range of depth and a range of the most common dip angle for these events.
The Mw 6.9 outer-rise earthquake occurred in 2016 surrounding the subduction zone of Nicaragua may be triggered by the interplate Mw 7.3 earthquake occurred in 2012 in the same area. An analysis of the 2016 Nicaragua outer-rise earthquake was carried out by tsunami simulation, considering linear dispersion; taking as input parameters, the values for hypocenter location and focal mechanism given from CMT solution. The best fault model for the earthquake and the slip amount were found by comparing the simulated tsunami signal and observed tsunami signal at the DART32411 buoy.
Under the consideration that interplate events can trigger huge outer-rise events, we performed a tsunami simulation considering a tsunami triggered by an outer-rise event with Mw 8.4 located in the same area as the 1992 Nicaragua events. GEBCO bathymetry of 30 arc-minutes and SRTM of 3 arc-seconds were used to perform the tsunami inundation. The comparison between inundation measures obtained by simulation and measures surveyed in 1992 shows that an outer-rise event with this magnitude could cause a similar effect to the last devastated tsunami earthquake in 1992.
Since outer-rise events represent a real tsunami hazard for the Pacific coast of Nicaragua, the study of these earthquakes must be considered for the disaster prevention policies and countermeasure processes.
Keywords: Outer-rise Earthquake Characteristics, Linear Dispersion, Tsunami Simulation