Repeated cross-correlations of ambient seismic noise indicate a long-term seismic velocity change associated with the 2006 M7.5 slow-slip event (SSE) in the Guerrero region, Mexico. Because the SSE does not radiate seismic waves, the measured velocity change cannot be associated with the response of superficial soil layers to strong shaking as observed for regular earthquakes. The perturbation ...

Detection of debris flow occurrence can be efficiently obtained through different types of sensors. A pair of ultrasonic sensors placed at a known distance from each other along a torrent have been used as a method to obtain mean front velocity of debris-flows, in addition to their use as detectors of debris flow occurrence. Also seismic and acoustic sensors have been employed to measure debris...

In this dissertation, I investigate the assembly and evolution of the Archean cratonic lithosphere by using two complementary seismological methods to image the lithospheric structure of the Slave craton in Canada. First, I perform surface wave tomographic inversions to constrain the depth dependence of Rayleigh wave phase velocity, shear wave velocity, and azimuthal anisotropy of the Slave cra...

Aligned vertical fractures introduce velocity anisotropy which is directly related to parameters, such as fracture density, fracture shape and fracture contents. Effective medium models allow us to study qPand qS-wave velocity anisotropy in rocks with aligned vertical fractures, intersecting fracture sets and aligned fractures with smallscale porosity. Spatially varying fracture density distrib...

laboratory data, which relate the liquefaction resistance of firoozkooh sand and non-plastic silt mixtures to shear wave velocity are presented and compared to liquefaction criteria derived from seismic field measurements by andrus and stokoe [1]. in the work described herein, cyclic triaxial and resonant column tests were conducted on specimens of clean sand and sand-silt mixtures with silt co...

Shear and Compressional Wave Velocities along with other Petrophysical Logs, are considered as upmost important data for Hydrocarbon reservoirs characterization. Shear Wave Velocity (Vs) in Well Logging is commonly measured by some sort of Dipole Logging Tools, which are able to acquire Shear Waves as well as Compressional Waves such as Sonic Scanner, DSI (Dipole Shear Sonic imager) by Schlumbe...

Abstract The application of quantitative interpretation techniques for hydrocarbon prospect evaluation from seismic has become so vital. effective employment these is dependent on several factors: the quality and well data, sparseness physics rock, lithological structural complexity field. This study adopts reflection pattern, amplitude versus offset (AVO), Biot–Gassmann fluid substitution cros...

Earthen dams and levees are prone to progressive failure through internal erosion of their structure. Internal erosion is often invisible to current methods of inspection until it manifests itself at the exterior surface. This study focuses on the novel use of passive seismic interferometry to monitor temporal changes in earthen embankments caused by internal erosion. This technique uses the am...

[1] We present results from the cross-correlations of seismic noise recordings among pairs of stations in the Parkfield network, California. When performed on many station pairs at short ranges, the noise correlation function (NCF) is the passive analog to a shot gather made with active sources. We demonstrate the presence of both a P-wave and a Rayleigh wave in the NCF. A time-frequency analys...

Compressional(Vp) and shear-wave (Vs) velocities were determined within earthen levees on the Rio Grande River in south Texas, south New Mexico and New Orleans. A loosely fitting relationship was developed to better characterize the internal condition of the levees. Seismic data were incorporated with surface observations, existing core taken from the levee, and airborne EM data acquired. Sever...