A New Paradigm for Nuclear Explosion Monitoring of Test Sites and Broad Areas: Full Waveform Inversion Tomography and Moment Tensor Inversion With 3D Greens Functions
Description:
Advances in the workflow for full waveform inversion (FWI) tomography, improved open broadband waveform data sets and more powerful high-performance computing (including GPU accelerated platforms) now make it possible to easily develop three-dimensional (3D) seismic Earth models for improved simulations of complete waveforms. Regional- and continental-scale FWI models enable physics-based simulations of observed complete waveforms including path-specific propagation effects of wavespeed heterogeneity. Forward waveform simulations in 3D models can provide Greens functions (GFs) for source inversions to estimate the moment tensor, seismic moment (and magnitude) as well as depth and location. This presentation will demonstrate how FWI tomography models can be obtained with modern workflow tools and openly available broadband waveform data. The resulting models improve waveform simulations for earthquakes and nuclear explosions. We show how reciprocity can be used to precompute databases of Strain Greens Tensors for use as receiver-side GFs. Precomputation of databases liberates operational pipelines from dependence on “on demand” HPC for event-specific analysis. Such databases can provide GFs via HDF5 file or webservices queries (e.g. InstaSeis). Rapid access of GFs enables stochastic inversions (e.g. Random Walk Hastings-Metropolis, Hamiltonian Monte Carlo) for source parameters with their improved representation of posterior probabilities (parameter variance and covariance). We propose that FWI models can be developed for nuclear test sites and broad areas enabling moment tensor inversion with improved accuracy provided by better representation of path-specific propagation effects. Stochastic inversions of source parameters with improved parameter uncertainties and covariances support quantitative source-type characterization that compliments traditional identification and magnitude/yield estimation.
Session: Advancements in Forensic Seismology and Explosion Monitoring - I
Type: Oral
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Arthur
Student Presenter: No
Invited Presentation:
Poster Number:
Authors
Arthur Rodgers Presenting Author Corresponding Author rodgers7@llnl.gov Lawrence Livermore National Laboratory |
Lars Gebraad lars.gebraad@mondaic.com Mondaic AG |
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A New Paradigm for Nuclear Explosion Monitoring of Test Sites and Broad Areas: Full Waveform Inversion Tomography and Moment Tensor Inversion With 3D Greens Functions
Category
Advancements in Forensic Seismology and Explosion Monitoring