Soft sediment thickness and shear-wave velocity estimation from the H/V technique up to the bedrock at meteorite impact crater site, Sao Paulo city, Brazil

摘要

To obtain shear wave velocity profile for near-surface application many geophysical techniques is used. The most recently used approach is the joint inversion of H/V spectral ratio curve and dispersion curve extracted from the multi-channel analysis of surface waves (MASW) survey. However, in some cases, it is difficult to acquired dispersion curve in engineering application frequency range 1-30 Hz. In that situation, dispersion curve can be indirectly inverted from all the available points of the frequency-VRayleigh curve to shear wave velocity and depth. This result a series of (s-wave velocity and depth) values through which a best-fit trend can be passed. The best fit gives us an idea of the rate of shear wave velocity increase with depth and shear wave velocity at one-meter depth. This information can later be utilized in an inversion of Rayleigh wave ellipticity curve.