Speaker: Giusi Ruggiero

Date: Thursday 20th of June 2024, 1:15pm.

Abstract:

Seismic images techniques such as full waveform inversion (FWI) are based on frequency band-limited seismic data, and therefore they can only recover the smooth version of a true earth model, which is not suited for a proper geological interpretation at the small-scale. A relation between this smooth model and the true model can be established through the homogenization technique. In this study, we use the inverse homogenization, or downscaling, to address the problem of quantifying structural uncertainty. In the proposed approach, we apply the homogenization operator in the context of the elastic FWI (HFWI) to obtain the corresponding effective medium. As a second step, we carry out the downscaling inversion: assuming the HFWI solution represents the effective elastic properties of a true earth model, we aim to recover small-scale information. We define the downscaling with a Bayesian formulation and we show, in the case of a 2D fault model, how the inversion strategy is able recover fault-related parameters such as the location, spatial extent of fault-related deformation, slope angle and maximum slip.