Preliminary results on the geomorphology and shallower structure of the south-western Hispaniola offshore margin.

Oblique convergence between the North American and Caribbean plates is accommodated in the Hispaniola Island by means of strain partitioning. A remarkable example of this process is the devastating M7.0 2010 Haiti event which occurred in SW Hispaniola. In this area, the relative convergence between the thick crusts of the island arc and the Caribbean igneous plateau is taking place. This has resulted in significant deformation by means of left-lateral transpression, indentation and uplifting in the SW Hispaniola and its insular margin. We studied the structure and morphology of the offshore southern margin of the Southern Peninsula (Haiti) and Bahoruco Peninsula (Dominican Republic). For that, we have compiled a large dataset of swath bathymetry and 2D seismic reflection profiles from several marine geophysical surveys (A2097L01-1978, FM0502-1980, CaribeNorte-2009, HaitiOBS-2010, HaitiSIS-2012, NorCaribe-2013). This study presents a preliminary mapping of the main morphotectonic provinces:  Island Slope, Haiti plateau and Haiti sub-basin. Noticeable features are active E-W and NW-SE trending folds and fault-propagation folds. As dominant active sedimentary processes are widespread gravity slumping, erosive canyon networks and extended areas of sediment waves. This study is in progress and will provide detailed observations on the active tectonic and sedimentary processes to help future studies assess the seismic and tsunami hazard.