Using Full-Waveform Inversion (FWI) to Decipher Southeast Asia’s Tectonics
Presenter
DescriptionSeismic tomography has played a crucial role in the illumination of deep Earth structure since the first pioneering studies of the mid 1970s. A wide range of tomographic methods now exist, but these are mostly based on seismic ray theory and hence do not fully account for the true physics of wave propagation. Full-waveform inversion (FWI) embraces the full complexity of seismic wave propagation by accurately solving the 3-D seismic wave equation numerically. While computationally more expensive than ray-based imaging methods, FWI coherently incorporates the effects of anisotropy, wavefront healing, interference and (de)focusing, and is thus especially suitable for strongly heterogeneous regions such as Southeast Asia.
Based on >3,000 h of analyzed waveform data, we image the seismic structure beneath Southeast Asia at periods between 20-150 s via an iterative non-linear inversion that begins from a 1-D reference model. At each iteration, the full 3-D wavefield is determined through an anelastic Earth using the spectral-element wave propagation solver Salvus (Afanasiev et al., 2019), accommodating effects of topography, bathymetry and ocean load. Our new model after 87 L-BFGS iterations reveals detailed anomalies down to the mantle transition zone, including multiple features associated with ongoing subduction, particularly along the Indonesian volcanic arc.
Based on >3,000 h of analyzed waveform data, we image the seismic structure beneath Southeast Asia at periods between 20-150 s via an iterative non-linear inversion that begins from a 1-D reference model. At each iteration, the full 3-D wavefield is determined through an anelastic Earth using the spectral-element wave propagation solver Salvus (Afanasiev et al., 2019), accommodating effects of topography, bathymetry and ocean load. Our new model after 87 L-BFGS iterations reveals detailed anomalies down to the mantle transition zone, including multiple features associated with ongoing subduction, particularly along the Indonesian volcanic arc.
TimeTuesday, June 2816:30 - 17:00 CEST
LocationSingapore Room
Session Chair
Event Type
Minisymposium
Climate, Weather and Earth Sciences
Computer Science and Applied Mathematics
Physics
