The equivalent body forces for a stress-drop seismic source are found. When the isotropic stress drop and one of the three principal stress drops are zero, then the equivalent body forces are the same double couple without moment which would result from a shear dislocation. In general however, all six stress-drop components must be specified as independent functions of time. THE STRESS-DROP SOU...

Source mechanisms of 26 large shallow earthquakes are determined in terms of a double-couple point source with a correction for the nondirectional part of source finiteness by using P-wave first motions and long-period Rayleigh wave spectra recorded on WWSSN, IDA, and GDSN networks. The combined use of both data sets allows us to determine the double-couple mechanism uniquely in most cases. Con...

We study the Darcy problem with log-normal permeability, modeling the fluid flow in a heterogeneous porous medium. A perturbation approach is adopted, expanding the solution in Taylor series around the nominal value of the permeability. The resulting recursive deterministic problem satisfied by the expected value of the stochastic solution, analytically derived and studied in [4], is discretize...

The seismic moment and source orientation of the 8 November 1980 Eureka, California, earthquake (Ms = 7.2) are determined using long-period surface and body wave data obtained from the SRO, ASRO, and IDA networks. The favorable azimuthal distr ibution of the recording stations allows a well-constrained mechanism to be determined by a simultaneous moment tensor inversion of the Love and Rayleigh...

This study presents the application of an automated moment tensor analysis procedure on microcracks which were generated during a triaxial compression test of a cylindrical rock salt specimen (diameter 150 mm, length 300 mm). The acoustic emission signals were detected in a frequency range between 20 kHz and 1 MHz using 12 acoustic emission sensors mounted on the surface of the specimen cylinde...