Triaxial experiments show that samples of fault gouge deform distinctly differently than those from the adjacent fault damage zone (e.g., Chester and Logan, 1986). Rock samples in the damage zone follow a characteristic elastic-brittle behavior, whereas fault gouge readily compacts and deforms in a more ductile manner. In order to explain the apparent weakness of large plate bounding faults suc...

A devasting Mw7.2 earthquake struck southern Haiti on 14 August 2021, leading to over 2000 casualties and severe structural failures. This earthquake, which ruptured ~70 km west of the 2010 Mw7.0 event, offers a rare opportunity probe mechanical properties Haiti. study investigates kinematic multi-fault coseismic rupture process by jointly analyzing teleseismic interferometric synthetic apertur...

We review some basic features of shear wave generation and energy balance for a 2D antiplane rupture. We first study the energy balance for a flat fault, and for a fault that contains a single localized kink. We determine an exact expression for the partition between strain energy flow released from the elastic medium surrounding the fault, radiated energy flow and energy release rate. This bal...

We have determined a source rupture model for the 1992 Landers earthquake (Mw 7.2) compatible with multiple data sets, spanning a frequency range from zero to 0.5 Hz. Geodetic survey displacements, near-field and regional strong motions, broadband teleseismic waveforms, and surface offset measurements have been used explicitly to constrain both the spatial and temporal slip variations along the...

We have determined a source rupture model for the 1992 Landers earthquake (Mw 7.2) compatible with multiple data sets, spanning a frequency range from zero to 0.5 Hz. Geodetic survey displacements, near-field and regional strong motions, broadband teleseismic waveforms, and surface offset measurements have been used explicitly to constrain both the spatial and temporal slip variations along the...

Spontaneous bilateral mode II shear ruptures were nucleated on faults in photoelastic Homalite plates loaded in uniaxial compression. Rupture velocities were measured and the interaction between the rupture front and short fault branches was observed using high-speed digital photography. Fault branches were formed by machining slits of varying lengths that intersected the fault plane over a ran...

[1] We studied the complex multiple-faulting pattern of the 40-km-long rupture zone of the 1999 M7.1 Hector Mine, California, earthquake with fault zone trapped waves generated by near-surface explosions and aftershocks, and recorded by linear seismic arrays deployed across the surface rupture. The explosion excited trapped waves, with relatively large amplitudes at 3–5 Hz and a long duration o...

[1] Earthquake ruptures are modeled as dynamically propagating shear cracks with the aim of gaining insight into the physical mechanisms governing their arrest or, otherwise, the often-observed variations in rupture speeds. Fault bends have been proposed as being the main cause for these variations. Following this line of reasoning, the existence of deviations from fault planarity is chosen as ...

Observations and modeling of 3- to 6-hertz seismic shear waves trapped within the fault zone of the 1992 Landers earthquake series allow the fine structure and continuity of the zone to be evaluated. The fault, to a depth of at least 12 kilometers, is marked by a zone 100 to 200 meters wide where shear velocity is reduced by 30 to 50 percent. This zone forms a seismic waveguide that extends alo...

The 2021 August 14 MW 7.2 Nippes, Haiti earthquake occurred 75 km west of the epicenter 2010 Leogane (Haiti) on transpressive Caribbean - North America plate boundary. We present an updated fault map for Hispaniola and model coseismic early postseismic slip using Interferometric Synthetic Aperture Radar pixel offsets. find ruptured multiple segments Enriquillo-Plantain Garden Fault Zone. Slip i...