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...

Existing data on source parameters of large crustal earthquakes (subduction events are not considered here) over a wide range of repeat imes indicate that, for a given magnitude (Ms or Mw), earthquakes with long repeat times have shorter fault lengths than those with short repeat imes. A shorter fault length for a given magnitude indicates a larger average stress drop which reflects the average...

We analyze Bouguer anomalies in/around the focal region of the 2016 Kumamoto earthquake to examine features, such as continuity, segmentation and faulting type, of the active fault zones related to the earthquake. Several derivatives and structural parameters calculated from a gravity gradient tensor are applied to highlight the features. First horizontal and vertical derivatives, as well as a ...

[1] We systematically investigate the velocity contrast along the Calaveras fault that ruptured during the 1984 Morgan Hill earthquake using fault zone head waves (FZHW) that refract along the fault interface. We stack waveforms in 353 sets of repeating clusters, and align the peaks or troughs of the direct P waves assuming rightlateral strike-slip focal mechanisms. The obtained velocity contra...

1. Location map of selected fault-controlled valleys in western Idaho and northeastern Oregon 3 2. Plot of all scarp height and slope angle values obtained in this study 5 3. Map of sackung features, vegetation lineaments, and landslide headscarps on West Mountain 6 4. Map of Meadows Valley, showing approximate trace of Meadows Valley fault zone 8 5. Surficial geologic map of the north end of M...