Elastic FWI of Surface Waves for Near-Surface Characterization of Middle East Land Data

The south of the Sultanate of Oman is characterized by very strong lateral and vertical velocity contrasts that make seismic imaging particularly challenging. In this context, full waveform inversion (FWI) appears promising. The first attempts based on acoustic FWI implementations faced difficulties in this region because the characterization of the complex near surface is critical for the success of acoustic FWI and imaging of the deeper layers. Acoustic FWI was initially coupled with near-surface characterization methods, such as inversion of the dispersion curves of surface waves, which introduces some elastic properties in the process. We take here a step further by applying elastic FWI to surface waves for an improved near-surface characterization. Since surface waves are primarily sensitive to Vs, the associated inverse problem is less prone to cross-talk with other elastic parameters. Moreover, our workflow benefits from the ultra-low frequencies recovered by interferometry. We present an application using a dataset from the south of the Sultanate of Oman that combines elastic FWI for Vs using virtual and active data and utilizes this Vs model to constrain the shallow Vp model.