קולוקוויום בחוג לגאופיזיקה: Local Angle Domain EigenWave Inversion

Zoom: https://tau-ac-il.zoom.us/j/83888751261?pwd=36z53wLKBh2swtqb0scG5UTUYs2g95.1

Abstract:

Seismic full-waveform inversion (FWI) has become a key technology for retrieving high-resolution subsurface model parameters (e.g., elastic and viscoelastic properties, including density). Being inherently multiscale, it is applied across a wide range of disciplines, from global seismology, lithospheric imaging and deep crustal characterization to hydrocarbon exploration, reservoir monitoring, near-surface investigation and even medical imaging.

FWI is formulated as a nonlinear optimization problem that minimizes the misfit between the observed seismic data and the data simulated (modelled) with the current estimate of the model parameters. However, its practical application remains challenging due to cycle skipping, cross-talk between parameter classes and the complexity of wave propagation in realistic Earth models.

In this talk, I will present Local Angle Domain EigenWave Inversion (LAD-EWI), a new framework that combines finite-frequency, ray-based wave physics (EigenWaves, the finite-frequency extension of two-point EigenRays) with local angle-domain scattering wavefield analysis. The method represents seismic information in phase space, enabling the inversion to operate on local angle-domain gathers, parameterized by directional angles (dip and azimuth of the local reflector normal) and reflection angles (opening angle and opening azimuth), rather than on conventional space–time wavefields alone. This perspective provides greater physical insight into wave propagation and scattering, naturally handles multipathing and anisotropic effects, and offers a promising route toward more robust and interpretable waveform inversion. I will discuss the theoretical foundations of the method and illustrate its potential with synthetic examples, highlighting its connection to recent developments in phase-space local angle-domain waveform inversion [3] and finite-frequency EigenWaves [4], which build on full-azimuth local angle-domain decomposition and imaging [1, 2].

References

1. Koren, Z. & Ravve, I., 2011. Full-azimuth subsurface angle domain wavefield decomposition and imaging Part I: Directional and reflection image gathers, Geophysics, 76(1), S1–S13.

2. Ravve, I. & Koren, Z., 2011. Full-azimuth subsurface angle domain wavefield decomposition and imaging: Part 2 — Local angle domain, Geophysics, 76(2), S51–S64.

3. Koren, Z., 2026. Theoretical framework for phase-space local-angle-domain waveform inversion in anisotropic elastic media, arXiv:2608.04901.

4. Koren, Z., 2026. Eigenwaves: Finite-frequency eigenrays in anisotropic elastic media, arXiv:2610.04101.

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