Three‐dimensional dynamic rupture simulations across interacting faults: TheM_w7.0, 2010, Haiti earthquake

Abstract

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 M7.9 Denali USA and 2010 M7.1 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 M6.9 Loma Prieta and 2010 M7.0 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.

3‐D velocity structure in southern Haiti from local earthquake tomography

“…Bimaterial fault interfaces also influence ground motion during an earthquake [Ben-Zion, 2001]. Therefore, this result is vital to assess ground motion level from potential earthquake scenarios mainly on the EPGF not only because this fault still remains a major seismic threat for the nearby cities in southern Haiti [Calais et al, 2010;Douilly et al, 2015;Prentice et al, 2010;Symithe et al, 2013] but also because sedimentary basin could trap the energy and significantly amplify the ground shaking [Day et al, 2006;Olsen, 2000;Wald and Graves, 1998]. As an example, Komatitsch et al [2004] used a spectral element method to simulate ground motion in the Los Angeles basin and their results uncover large amplification within the basin for their 3-D simulation with respect to their 1-D case.…”

“…They also infer that a change in elastic properties with depth could explain the upward termination of the Loma Prieta earthquake. The 2010 Haiti earthquake and the 1989 Loma Prieta earthquake share several similarities in tectonics and earthquake rupture processes [Douilly et al, , 2015Symithe et al, 2013]. They both involved rupture initiation on smaller blind thrust fault adjacent to major strike-slip fault without transferring to the main fault.…”

“…The 2010 M7.0 Haiti earthquake ruptured the multisegment Léogâne fault [Douilly et al, , 2015Meng et al, 2012;Symithe et al, 2013], killed about 240,000 people, and caused heavy damage in the Port-au-Prince region equivalent to the country's annual gross national product [Bellerive, 2010]. As tragic as this event was, data collected during this event and its associated aftershocks provide useful insight to better understand the tectonics of this region.…”

A Probable Earthquake Scenario near Istanbul Determined from Dynamic Simulations

“…On the other hand, numerical simulations incorporating the mechanics of earthquake rupture (hereafter termed dynamic simulation) revealed that the earthquake rupture, under typical tectonic loading, is controlled by intrinsic features of the fault macroscopic structure . In particular, the fault geometry plays a significant role in the earthquake process as inferred from numerical simulations (e.g., Harris and Day, 1999;Oglesby et al, 2003;Aochi and Kato, 2010;Kase, 2010;Fukuyama and Hao, 2013;Douilly et al, 2015), as well as from geological observations (e.g., King and Nábĕlek, 1985;Wesnousky, 2008). The aim of this study is to make use of high-performance computing of dynamic simulations to infer the likelihood of several earthquake scenarios in the Sea of Marmara.…”

Dynamic and Quasi‐Dynamic Modeling of Injection‐Induced Earthquakes in Poroelastic Media

“…Simulations of earthquake rupture in complex scenarios or involving earthquake sequences often use the so-called quasi-dynamic approach (Erickson & Day, 2016;Erickson & Dunham, 2014;Douilly et al, 2015;Rice, 1993;Rice et al, 2001;Wei et al, 2013), in which inertial effects are neglected. Slip instability under quasi-static mechanics leads to unbounded slip speeds, and the singularity is resolved through a radiation damping approximation, that is, by adding a velocity-dependent cohesion that bounds the slip velocity at rupture fronts (Rice, 1993;Rice et al, 2001).…”