The 1992 Landers earthquake sequence: Earthquake occurrence and structural heterogeneities

The 1992 Landers Earthquake Sequence: Earthquake Occurrence and Structural Heterogeneities

The June 28, 1992, Mw 7.3 Landers earthquake occurred in the southeastern Mojave Desert, California. Over 10,000 aftershocks of the earthquake were recorded by the Caltech-USGS Southern California Seismic Network (SCSN) in 1992. To investigate the relationship between complexities in the crustal structure and variations in seismicity, we have used a tomographic method to invert 145,098 P wave a...

The 1992 Landers Earthquake Sequence: Seismological Observations

The (Mw6.1, 7.3, 6.2) 1992 Landers earthquakes began on April 23 with the Mw6.1 1992 Joshua Tree preshock and form the most substantial earthquake sequence to occur in California in the last 40 years. This sequence ruptured almost 100 km of both surficial and concealed faults and caused aftershocks over an area 100 km wide by 180 km long. The faulting was predominantly strike slip and three mai...

Aftershocks and Pore Fluid Diffusion Following the 1992 Landers Earthquake

Modeling afterslip and aftershocks following the 1992 Landers earthquake

[1] One way to probe the rheology of the lithosphere and fault zones is to analyze the temporal evolution of deformation following a large earthquake. In such a case, the lithosphere responds to a known stress change that can be assessed from earthquake slip models constrained from seismology and geodesy. Here, we model the postseismic response of a fault zone that is assumed to obey a rate-str...

State of Stress from Focal Mechanisms Before and After the 1992 Landers Earthquake Sequence

The state of stress in the Eastern California Shear Zone (ECSZ) changed significantly because of the occurrence of the 1992 Mw 6.1 Joshua Tree and the Mw 7.3 Landers earthquakes. To quantify this change, focal mechanisms from the 1975 Galway Lake sequence, the 1979 Homestead Valley sequence, background seismicity from 1981 to 1991, and the 1992 Landers sequence are inverted for the state of str...