Fault zone structure determined through the analysis of earthquake arrival times

Three‐dimensional VP and VP/VS Velocity Models of the Los Angeles basin and central Transverse Ranges, California

“…An averaging vector is a row in the resolution matrix. Where the density of seismic rays is high within the model we expect good resolution and small values of the spread function [Michelini, 1991 ].…”

“…The smaller the damping, the higher the resolution and the larger the average standard error is ( Figures A4e and A4f) In general, the damping for the Ve models is higher than for the Ve/Vs models simply because the P data set is bigger than the S-P data set. The S-P data are of inherently lower quality than the P data because some stations only have a parameter has a small resolving width, while less welldefined parameters have broad kernel shapes and small overall values of the resolving kernel [Michelini, 1991 ]. An averaging vector is a row in the resolution matrix.…”

Integrated High Resolution Microearthquake Analysis and Monitoring for Optimizing Steam Production at The Geysers Geothermal Field, California

“…The event is located using a program developed by Michelini (1991) which can also be used to perform a simultaneous inversion for location and velocity model. At this point, the program is used only to determine the location of the event.…”

Heterogeneous slip and rupture models of the San Andreas fault zone based upon three-dimensional earthquake tomography

“…Thurber, 1983;Eberhart-Phillips, 1989;Michelini andMcEvilly, 1991, Michelini, 1991) have advanced during the . past decade to a degree that makes it possible to define major subsurface lithologic inhomogeneities along well-instrumented active fault zones to a resolution of a few kni.…”

“…Information on sub-surface lithology interpreted from the Lorna Prieta and Parkfield three-dimensional crustal velocity models computed by Michelini (1991) is integra~ed with information on slip behavior provided by the distributions of earthquakes located using the three-dimensional models and by surface creep data to study the relationships between large-scale lithological heterogeneity and slip segmentation along these two sections of the fault zone. The velocity models are calibrated using published velocitypressure and velocity-temperature data for basement rock types that outcrop within the study areas, and both models are in good agreement with published refraction surveys.…”