Shear Wave Imaging by Inverting Surface Wave Dispersion Curves Extracted From Train Induced Vibrations and Urban Traffic Noise
Description:
Train induced vibrations are exceptionally good source of surface wave energy and provide a unique type of opportunistic source for subsurface shear wave velocity imaging using approaches based on seismic interferometry. Similarly, urban traffic noise is also abundant in surface wave energy in higher frequency range (1-15 Hz) and could be used to resolve the near surface structure. However, the presence of local sources outside the stationary phase zone causes bias in the estimation of surface wave dispersion via seismic interferometry. We develop a novel array processing technique, based on Matched Field Processing (MFP), for large-N style arrays to capture local source locations first and then extract more accurate surface wave phase velocity dispersion curves. The extracted multimodal dispersion curves are then inverted using a non-linear Markov chain Monte Carlo (McMC) method to retrieve the shear wave velocity structure. The addition of higher-mode dispersion curves reduces non-uniqueness and provide an improved high-resolution shear-wave velocity structure.
We analyze datasets from Tierra Grande nodal deployment which utilizes multiple sub-arrays of 10 to 20 elements placed at different locations from the railroad track over the Socorro Magma Body (SMB). We compare dispersion curves extracted from train induced vibrations using data from a spiral sub-array array deployed near railroad tracks with dispersion curves from a spiral sub-array far from railroad tracks. Our analysis clearly demonstrates the effectiveness of MFP approach for dispersion curve extraction using train induced vibrations as opportunistic sources in higher frequency band. We further demonstrate the potency of our approach with a DAS cable deployment at University of Louisiana at Lafayette, deployed for monitoring water table variation in south Louisiana that recorded urban traffic noise.
Session: New Directions in Environmental, Seismic Hazard and Mineral Resource Exploration Studies [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Yashwant
Student Presenter: Yes
Invited Presentation:
Poster Number: 118
Authors
Yashwant Soni Presenting Author Corresponding Author yashwant_soni1@baylor.edu Baylor University |
Jay Pulliam jay_pulliam@baylor.edu Baylor University |
Rui Zhang rui.zhang@louisiana.edu University of Louisiana at Lafayette |
Diego Quiros diego.quiros@uct.ac.za University of Cape Town |
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Shear Wave Imaging by Inverting Surface Wave Dispersion Curves Extracted From Train Induced Vibrations and Urban Traffic Noise
Category
New Directions in Environmental, Seismic Hazard and Mineral Resource Exploration Studies