1. Crustal Structure and Fault Geometry of the 2010 Haiti Earthquake from Temporary Seismometer Deployments
- Author
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Susan E. Hough, William L. Ellsworth, Roby Douilly, Bernard Mercier de Lépinay, Saint-Louis Mildor, Steeve Symithe, Jennifer S. Haase, Eric Calais, John G. Armbruster, Marie-Paule Bouin, Anne Deschamps, Mark Meremonte, Department of Earth and Atmospheric Sciences [West Lafayette], Purdue University [West Lafayette], Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, US Geological Survey [Pasadena], United States Geological Survey [Reston] (USGS), Observatoire Volcanologique de Guadeloupe, Department of Earth, Atmospheric, and Planetary Sciences [West Lafayette] (EAPS), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Géoazur (GEOAZUR 6526), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Bureau des mines et de l'énergie, Bureau des mines et de l'énergi, US Geological Survey [Santa Cruz], Scripps Institution of Oceanography (SIO - UC San Diego), University of California (UC)-University of California (UC), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Seismic gap ,Seismometer ,geography ,Strike and dip ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Geometry ,Fault (geology) ,Induced seismicity ,010502 geochemistry & geophysics ,Geodesy ,01 natural sciences ,Geophysics ,13. Climate action ,Geochemistry and Petrology ,Interferometric synthetic aperture radar ,Submarine pipeline ,Aftershock ,Seismology ,Geology ,0105 earth and related environmental sciences - Abstract
International audience; Haiti has been the locus of a number of large and damaging historical earthquakes. The recent 12 January 2010 Mw 7.0 earthquake affected cities that were largely unprepared, which resulted in tremendous losses. It was initially assumed that the earthquake ruptured the Enriquillo Plantain Garden fault (EPGF), a major active structure in southern Haiti, known from geodetic measurements and its geomorphic expression to be capable of producing M 7 or larger earthquakes. Global Positioning Systems (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data, however, showed that the event ruptured a previously unmapped fault, the Léogâne fault, a north‐dipping oblique transpressional fault located immediately north of the EPGF. Following the earthquake, several groups installed temporary seismic stations to record aftershocks, including ocean‐bottom seismometers on either side of the EPGF. We use data from the complete set of stations deployed after the event, on land and offshore, to relocate all aftershocks from 10 February to 24 June 2010, determine a 1D regional crustal velocity model, and calculate focal mechanisms. The aftershock locations from the combined dataset clearly delineate the Léogâne fault, with a geometry close to that inferred from geodetic data. Its strike and dip closely agree with the global centroid moment tensor solution of the mainshock but with a steeper dip than inferred from previous finite fault inversions. The aftershocks also delineate a structure with shallower southward dip offshore and to the west of the rupture zone, which could indicate triggered seismicity on the offshore Trois Baies reverse fault. We use first‐motion focal mechanisms to clarify the relationship of the fault geometry to the triggered aftershocks.
- Published
- 2013
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