Integrated Mapping of Active Faults and Seismic Hazard Evaluation for the example of Haiti

Abstract

This study presents a comprehensive mapping and analysis of active onshore and offshore faults in the North-West and South peninsula of Haiti, with implications for seismic hazard assessment. Field investigations (2017-2019), high-resolution satellite imagery, morphotectonic analysis, and structural data were integrated to identify and characterize major and secondary active faults. Kinematic analyses of onshore active faults indicate a dominant NNE–SSW compressional regime with oblique deformation. This pattern aligns with the regional stress field imposed by the relative motion of the Caribbean and North American plates. Despite limited historical seismicity, geomorphic and structural evidence demonstrates the recent and ongoing activity on the identified onshore faults. Deterministic seismic hazard assessment, incorporating fault geometry, segmentation, and kinematics, was conducted to estimate physically plausible maximum magnitudes (Mmax) and peak ground accelerations using multiple ground-motion prediction equations. Results indicate the highest onshore PGA values (up to ≥0.42 g) are associated with the Enriquillo–Plantain Garden Fault Zone, while secondary faults also contribute significantly to local ground motions. These highlight the critical role of both major and secondary active faults in controlling regional seismic hazard and underscore the importance of integrating detailed fault mapping into hazard models, particularly in regions with limited historical seismic records.