Testing the Amplitude of Ambient-field Green’s Function by Simulated Scattered Waves in a 3D Sedimentary Basin

Shiying Nie, & Shuo Ma

Submitted August 14, 2018, SCEC Contribution #8586, 2018 SCEC Annual Meeting Poster #107

We numerically simulate the scattered waves in a 3D sedimentary basin by using small-scale heterogeneities with 4421 point sources, uniformly distributed surrounding the basin. The simulated scattered wave fields make an ideal environment to test different methods of extracting the amplitude of Green’s functions from the random field, as the deterministic station-to-station Green’s functions can be computed in the known velocity structure. Our results show that both raw correlation- and deconvolution-based Green’s functions extracted from the scattered wave fields match well with the deterministic Green’s functions in terms of amplitude and phase, i.e., clear basin amplification is reproduced from either the correlation or deconvolution approach. The data processing methods of the cross-correlation approach—mainly one-bit and whitening—generally worsen the fit between retrieved and simulated Green’s function. In a realistic setting where the noise source distribution is non-uniform, however, we expect that both approaches may lead to possible biases in the amplitude of ambient-field Green’s functions.

Citation
Nie, S., & Ma, S. (2018, 08). Testing the Amplitude of Ambient-field Green’s Function by Simulated Scattered Waves in a 3D Sedimentary Basin . Poster Presentation at 2018 SCEC Annual Meeting.


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