H/V amplitude ratio measurement using multicomponent ambient noise cross-correlations and its relationship to Vp/Vs
Abstract
R etriev al of sub-surface V p - structure using A mbient N oise C ross- C orrelation (ANCC) is more challe n ging than retrieving V s - structure ( by inversion of surface wave dispersion curves ), and has been addressed by only a few researchers. W e explore the potential of ANCC for V p -imaging, using Rayleigh wave ellipticity, which has shown higher sensitivity to V p and ρ in comparison to surface wave phase and group velocity dispersion . O ur aim is to study the effect of V p on H/V ratio s measured from multicomponent ANCC waveforms, which are modelled rigorously using spatially uncorrelated but arbitra r ily distributed noise sources. We utiliz e the analytical expression for the Rayleigh wave Green function in a 1-D (vertically stratified) medium. We simulat e ANCC waveforms for a suite of subsurface models covering a range of V p / V s values, and compute H/V ratios in each case. The dependence of these measurements on model V p /V s is contrasted with the that of the classic Rayleigh H/V, for a variety of source distributions ranging from uniform to strongly anisotropic. Finally, w e add noise to our synthetic ANCC waveforms, to assess whether the sensitivity of the mesurements to V p rises above typical noise levels in passive seismic data.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMS019.0010M
- Keywords:
-
- 7203 Body waves;
- SEISMOLOGY;
- 7255 Surface waves and free oscillations;
- SEISMOLOGY;
- 7270 Tomography;
- SEISMOLOGY;
- 7299 General or miscellaneous;
- SEISMOLOGY