Finite Frequency Sensitivity Kernel for the Differential Measurements of Ambient Noise Correlations: Theory and Numerical Tests

Date: 4/25/2019

Time: 02:30 PM

Room: Elliott Bay

Full waveform adjoint tomography has achieved great success in applications from global structure using earthquakes to exploration seismology using active sources. When combined with ambient seismic noise interferometry, however, the shape of the sensitivity kernel can be distorted with significant sensitivity outside the inter-station region due to non-isotropic distribution of far field noise sources. We compute the sensitivity kernel for ambient noise cross-correlation differently from existing approaches by introducing an additional station to the classic two-station setting. We compute sensitivity kernels for differential travel time and amplitude measurements. The differential sensitivity kernels show prospect for canceling the overlapping part of the original source and structure kernels for two pairs of stations in interferometry, thus reducing the effect of non-isotropically distributed and non-stationary noise sources. We derive analytically and calculate numerically the differential sensitivity kernel for seismic interferometry and show examples based on 2D membrane waves. Our results for multiple station pairs show promise for future velocity and attenuation tomography based on seismic noise interferometry (Liu & Beroza 2019, submitted).

Presenting Author: Xin Liu

Authors