Estimations of Ambient Seismic Noise Sources Around Antarctica From Waveform Inversions of Multi-Component Rayleigh-Wave Crosscorrelations

Date: 4/26/2019

Time: 06:00 PM

Room: Grand Ballroom

The ambient seismic noise source distribution is a critical, and often under characterized, component of ambient noise imaging and monitoring methods. In practice, seismic sources are non-uniformly distributed around receivers, which leads to errors when the cross-correlation results are interpreted as Green's functions. The cross-correlations themselves contain both source and structure information, and one must unravel the source information if one wants to estimate structure information from noise correlations. Complimentary to the structure information, estimates of the source location(s) are useful to study and monitor source processes. Here we present a source location inversion scheme based on full-waveform inversion of ambient noise cross-correlations to provide an accurate estimation of sources in and around the Antarctic continent. We compare our results with other source imaging methods (e.g. matched-field processing). We have implemented a fully elastic waveform inversion, and we will discuss the use of different misfit functions (e.g. full waveforms or travel-time) in the source inversion process. We discuss related sensitivities to inversion parameters (e.g. the starting model) and explain the physics behind the different types of source kernels derived from the misfit functions. Finally, we discuss the benefits of using the multicomponent cross-correlations during noise estimation as opposed to only the vertical component correlations.

Presenting Author: Zongbo Xu

Authors