NHESS Natural Hazards and Earth System Sciences NHESS Nat. Hazards Earth Syst. Sci. 1684-9981 Copernicus Publications Göttingen, Germany 10.5194/nhess-14-2577-2014 Revision of the geological context of the Port-au-Prince metropolitan area, Haiti: implications for slope failures and seismic hazard assessment Terrier M. 1 Bialkowski A. 1 Nachbaur A. 2 Prépetit C. 3 Joseph Y. F. 4 BRGM, 3 Avenue Claude Guillemin, BP 36009, 45060 Orléans CEDEX 2, France BRGM, Villa Bel Azur, 4 Lot. Miramar, Route de la pointe des Nègres, 97200 Fort-de-France, Martinique, French West Indies BME, P.O. Box 2174, Port-au-Prince, Haiti LNBTP, Rue Toussaint Louverture, #27, Port-au-Prince, Haiti 26 09 2014 14 9 2577 2587 Copyright: © 2014 M. Terrier et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://nhess.copernicus.org/articles/14/2577/2014/nhess-14-2577-2014.html The full text article is available as a PDF file from https://nhess.copernicus.org/articles/14/2577/2014/nhess-14-2577-2014.pdf

Following the earthquake of 12 January 2010 in the Port-au-Prince area, the Haitian government, in close cooperation with BRGM, the French geological Survey, decided to undertake a seismic microzonation study of the metropolitan area of the capital in order to take more fully into account the seismic risk in the urbanization and planning of the city under reconstruction. As the first step of the microzonation project, a geological study has been carried out. Deposits of Miocene and Pliocene formations in a marine environment have been identified. These deposits are affected by the Enriquillo-Plantain Garden N80° E fault system and N110° E faults. Tectonic observations and morphological analysis indicate Quaternary activity of several faults mapped in the area of Port-au-Prince. These faults have a N110° trend and show a reverse-sinistral strike-slip motion. Moreover, on the basis of these geological results and of new topographical data, a hazard assessment of ground movements has been made. Along with the map of active faults, the hazard map of ground movements is an integral component of the seismic microzonation study.

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