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...

Initially, the devastating Mw 7.0, 12 January 2010 Haiti earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillo–Plantain Garden fault zone. Here, we combine seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process involved slip on ...

The San Diego trough fault zone (SDTFZ) is part of a 90-km-wide zone of faults within the inner California Borderland that accommodates motion between the Pacific and North American plates. Along with most faults offshore southern California, the slip rate and paleoseismic history of the SDTFZ are unknown. We present new seismic reflection data that show that the fault zone steps across a 5-km-...

Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-typ...

[1] Using dynamic rupture models, we examine the response of compliant fault zones that surround pre‐existing faults to nearby earthquakes. We find that some portions of a compliant fault zone can experience inelastic deformation due to dynamic stress perturbations, while the remaining portions deform elastically. Inelastic response of the fault zone results in sympathetic fault‐parallel motion...

[1] Pore pressure changes are rigorously included in Coulomb stress calculations for fault interaction studies. These are considered changes under undrained conditions for analyzing very short term postseismic response. The assumption that pore pressure is proportional to faultnormal stress leads to the widely used concept of an effective friction coefficient. We provide an exact expression for...

Batubesi Dam which is located in Sorowako region in the middle part of Sulawesi island had been designed with seismic coefficient about 0.20g. The region constitutes an active earthquake zone with the recurrence frequency and magnitude of the earthquake are relatively high. The region is located on and active fault zone due to lateral fault movement (strike-slip) of Matano fault, Palukoro fault...

[1] The initiation of frictional instability is investigated for simple models of fault zone using a linearized perturbation analysis. The fault interface is assumed to obey a linear slipweakening law. The fault is initially prestressed uniformly at the sliding threshold. In the case of antiplane shear between two homogeneous linearly elastic media, space-time and spectral solutions are obtaine...

Determining the relationship between crustal movement and faulting in thrust belts is essential for understanding the growth of geological structures and addressing the proposed models of a potential earthquake hazard. A Mw 5.9 earthquake occurred on 21 January 2016 in Menyuan, NE Qinghai Tibetan plateau. We combined satellite interferometry from Sentinel-1A Terrain Observation with Progressive...