Attenuation Estimation with Uncertainty Based on Seismic Noise Interferometry: Application to a Dense Array in Groningen, Netherlands
Abstract
Seismic wave attenuation provides important additional information to elastic structure for the shallow subsurface because it is sensitive to fractures, temperature, composition, and fluid content. It also has an important influence on strong ground motion. We develop a method based on noise cross-correlations of linear triplet of stations (Liu et al., 2015) that measures the relative amplitude decay. We assume that the quality factor, Q, is constant, and that the geometric spreading is the same for different frequencies within each narrow band. We combine our analysis with uncertainty quantification for the stacked noise cross-correlation (Liu & Beroza 2018) to estimate Q value and propagate the amplitude uncertainty to the uncertainty of Q value through linear least-squares analysis. We apply this method to the Loppersum dense 3C array in Groningen, Netherlands. For each virtual source, we construct amplitude maps with uncertainties for the fundamental and first higher Rayleigh wave modes. Unreliable amplitude measurements are identified and removed based on Signal-Noise Ratio (SNR) and spatial coherency. Our initial results of amplitude gradient maps show agreement with known geological features.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.S31D0546L
- Keywords:
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- 7260 Theory;
- SEISMOLOGYDE: 7270 Tomography;
- SEISMOLOGYDE: 7290 Computational seismology;
- SEISMOLOGY