Finite-Fault Simulation of Broadband Strong Ground Motion from the 2010 Mw 7.0 Haiti Earthquake

Because of the socioeconomic environment in the small island nation of Haiti, no seismic recording stations were operating in the source region at the time of the 2010 M-w 7.0 earthquake. The lack of strong motion instruments has hindered the estimation of the amplitude, duration, and frequency content of the ground shaking caused by the seismic event. In this study, synthetic broadband strong ground motions are generated in the vicinity of the 2010 Haiti earthquake. The low-frequency components of the synthetic motions are simulated using a slip model compatible with seismological observations, geologic field data, and space geodetic measurements. The computations are carried out using the discrete wavenumber representation method and the generalized transmission and reflection coefficient technique. The high-frequency ground-motion components are generated using the stochastic modeling approach and the specific barrier model. The two independently derived ground-motion components are subsequently combined using matched filtering at a crossover frequency of 1 Hz to generate broadband ground-motion time histories and response spectra for the city of Port-au-Prince and other sites in the vicinity of the earthquake. Finally, the synthetic strong ground motions are compared against peak ground-motion estimates inferred from the U. S. Geologic Survey ShakeMap of peak ground accelerations, ground-motion prediction equations, and observed structural damage. The synthetic time histories and response spectra generated in this study should be seen as plausible, but not necessarily unique, ground motions that capture the primary features of the 2010 Haiti earthquake.