Void detection is challenging due to the complexity of near-surface materials and the limited resolution of geophysical methods. Although multichannel, high-frequency, surface-wave techniques can provide reliable shear (S)-wave velocities in different geological settings, they are not suitable for detecting voids directly based on anomalies of the S-wave velocity because of limitations on the r...

shear wave velocity (vs) data are key information for petrophysical, geophysical and geomechanical studies. although compressional wave velocity (vp) measurements exist in almost all wells, shear wave velocity is not recorded for most of elderly wells due to lack of technologic tools. furthermore, measurement of shear wave velocity is to some extent costly. this study proposes a novel methodolo...

This paper studies the propagation of shear waves in a composite structure consisting of a piezoelectric layer perfectly bonded over a micropolar elastic half space. The general dispersion equations for the existence of shear waves are obtained analytically in the closed form. Some particular cases have been discussed and in one special case the relation obtained is in agreement with existing r...

Ground motions recorded within sedimentary basins are variable over short distances. One important cause of the variability is that local soil properties are variable at all scales. Regional hazard maps developed for predicting site effects are generally derived from maps of surficial geology; however, recent studies have shown that mapped geologic units do not correlate well with the average s...

Crustal velocity structure of the Chingshui-Tuchang area is obtained from the analysis of Pand S-wave arrivals of 257 local earthquakes recorded by a temporary seismic network in Ilan, northeastern Taiwan. The results of one-dimensional structure show that a major discontinuity in the uppercrust is found at the depth of 3 km for both Pand S-wave velocities. In addition, a significantly low S-wa...

W reflection seismology, surface waves or ground roll, are often considered a form of unwanted sourcegenerated noise. Unlike body waves, surface waves propagate exclusively in the lateral direction and are virtually insensitive to structure deeper than one wavelength. For a nominal frequency of 5 Hz and phase velocity of 500 m/s, this means that a surface wave of the Rayleigh or Love type only ...

summarythe explanation of the elastic, or velocity structure of the earth has long been a goal of the world’s seismologists. for the first few decades of seismological research, the investigation on velocity structure was restricted to the determination of one-dimensional models of the solid earth and of various regions within it. seismologists are currently obtaining three dimensional velocity...

Recent work by S. Lentz et al. documents offshore transport in the inner shelf due to a wave-driven return flow associated with the Hasselmann wave stress (the Stokes–Coriolis force). This analysis is extended using observations from the central Oregon coast to identify the wave-driven return flow present and quantify the potential bias of wind-driven across-shelf exchange by unresolved wave-dr...