Full SH-wavefield modelling and multiple-mode Love wave inversion

Improving the accurate assessment of a shear‐wave velocity reversal profile using joint inversion of the effective Rayleigh wave and multimode Love wave dispersion curves

“…This is a typical dispersion feature of Rayleigh waves when a thick LVL is present, noted for example in field tests by Forbriger () and Safani et al . (). As can be seen clearly in their reports, the effective Rayleigh dispersion curve is actually a superposition of several modes of propagation over the given frequency band.…”

“…As discussed by Safani et al . () for such a structure the mode energy distribution of Love wave modes is less regular, comprising many transitions between dominating higher modes, up and down with increasing frequency. They showed that Love wave inversion is obviously inaccurate when such an effective phase velocity dispersion is employed and multiple‐mode inversion of Love waves provided a more accurate estimate.…”

Finite-Difference Modeling and Dispersion Analysis of High-Frequency Love Waves for Near-Surface Applications

“…The layered half-space model is a fundamental model and widely used for most shallow investigations (e.g., XIA et al, 1999;BEATY et al, 2002;SAFANI et al, 2005SAFANI et al, , 2006. To test the staggered-grid FD code and study the propagation of Love waves, a two- …”

“…As its horizontally polarized counterpart, Love-wave propagation has been a topic of interest to crustal, earthquake, and engineering seismologists for many years. Because of their independence from Poisson's ratio and greater sensitivity to changes in S-wave velocity and layer thickness than Rayleigh waves (SONG et al, 1989;ZENG et al, 2007), more recently Love waves have received considerable attention in near-surface seismology, including data acquisition and survey parameters (WINSBORROW et al, 2003;ESLICK et al, 2008), dispersion extraction and inversion (LI, 1997;KINOSHITA, 1999;BEN-HADOR and BUCHEN, 1999;GUZINA and MADYAROV, 2005;SAFANI et al, 2005SAFANI et al, , 2006, and lateral inhomogeneity detection (LEE and MCMECHAN, 1992;YU et al, 1996;KE et al, 2006). Love waves are formed by constructive interference of multiple reflections of SH waves at the free surface, and their particle motion is parallel to the surface but perpendicular to the direction of propagation.…”

“…It is well known that Love-wave generation requires the existence of a low S-wave velocity layer in a multilayered earth model (e.g., STONELEY, 1950;GARLAND, 1979;ALEKSEEV, 1989;AKI and RICHARDS, 2002). Safani et al (2006) found that it is difficult to identify Love-wave mode when a low-velocity layer (LVL) is bounded by equally stiff layers. ESLICK et al, (2008) examined subsurface conditions and survey parameters for a LVL in order to record usable Love-wave data in near-surface seismology.…”