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Three‐dimensional dynamic rupture simulations across interacting faults: The M w 7.0, 2010, Haiti earthquake
Author(s) -
Douilly R.,
Aochi H.,
Calais E.,
Freed A. M.
Publication year - 2015
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2014jb011595
Subject(s) - seismology , geology , earthquake rupture , fault (geology) , elastic rebound theory , slip (aerodynamics) , shear (geology) , seismic gap , seismic hazard , strike slip tectonics , transform fault , engineering , petrology , aerospace engineering
The mechanisms controlling rupture propagation between fault segments during a large earthquake are key to the hazard posed by fault systems. Rupture initiation on a smaller fault sometimes transfers to a larger fault, resulting in a significant event (e.g., 2002 M 7.9 Denali USA and 2010 M 7.1 Darfield New Zealand earthquakes). In other cases rupture is constrained to the initial fault and does not transfer to nearby faults, resulting in events of more moderate magnitude. This was the case of the 1989 M 6.9 Loma Prieta and 2010 M 7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike‐slip plate boundary fault but did not propagate onto it. Here we investigate the rupture dynamics of the Haiti earthquake, seeking to understand why rupture propagated across two segments of the Léogâne fault but did not propagate to the adjacent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a finite element model to simulate propagation of rupture on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence, in particular, the ground displacement. The two slip patches inferred from finite fault inversions are explained by the successive rupture of two fault segments oriented favorably with respect to the rupture propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure.