Earthquake rupture is a notoriously complex process, at all observable scales. We introduce a simplified semi-dynamic crack model to investigate the connection between the statistical properties of stress and those of macroscopic source parameters such as rupture size, seismic moment, apparent stress drop and radiated energy. Rupture initiation is treated consistently with nucleation on a linea...

Several widely implemented and tested earthquake early warning algorithms employ empirical equations that relate earthquake magnitudes with groundmotion peak amplitudes and hypocentral distances. This approach is effective to the extent that the offline dataset available for setting the fitting coefficients in those equations is of sufficient quality and quantity. However, to address the proble...

Detailed analyses of teleseismic surface waves and body waves from the Guatemala e rthquake of February 4, 1976, show the following: (1) Left lateral displacement along a vertical fault with a strike varying from N66øE to N98øE is consistent with the teleseismic data. (2) The seismic moment was 2.6 X 102? dyn cm. The directivity ofthe surface wave radiation i dicates an asymmetric (1:2.3) bilat...

Seismological observations of the 2012 moment magnitude 8.6 Sumatra earthquake reveal unprecedented complexity of dynamic rupture. The surprisingly large magnitude results from the combination of deep extent, high stress drop, and rupture of multiple faults. Back-projection source imaging indicates that the rupture occurred on distinct planes in an orthogonal conjugate fault system, with relati...

Placing column lap-splice in the locations of possible nonlinear deformation may adversely affect the structures response to strong ground motions. Localization of damage in splice zone may change the structural response and prevent the load redistribution and development of a uniform pattern of nonlinear excursions among the various members. Validated by existing laboratory experiments, this s...

Analysis of broadband teleseismic data shows that the 18 June 2000 Wharton Basin earthquake, a moment magnitude 7.8 intraplate event in the region of diffuse deformation separating the Indian and Australian plates, consisted of two subevents that simultaneously ruptured two near-conjugate planes. This mode of rupture accommodates shortening by a mechanism different from that previously known el...

This work presents a high resolution source property study of hydraulic fracturing induced earthquakes in the Montney Formation, low-permeability tight shale reservoir Kiskatinaw area, northeast British Columbia, Canada. We estimate parameters, including focal mechanism solutions (FMSs), seismic moment, spectral corner frequency, and static stress drop values recorded between July 2017 2020. Wa...

S U M M A R Y Stress drop, a measure of static stress change in earthquakes, is the subject of numerous investigations. Stress drop in an earthquake is likely to be spatially varying over the fault, creating a stress drop distribution. Representing this spatial distribution by a single number, as commonly done, implies averaging in space. In this study, we investigate similarities and differenc...