Receiver function modelling of the lithosphere beneath the Sinai Subplate, west of the Dead Sea fault system

Abstract

The Sinai subplate in the eastern Mediterranean region separates the African and Arabian plates, and is demarcated on the east by the Dead Sea fault (DSF). The shallow and deep crustal Vs and Vp/Vs variations of the eastern Sinai subplate beneath Israel, as well as mantle properties, are not well constrained. With the recent development of the regional seismic network, we present new geophysical observations beneath the Sinai subplate. We focus on the crustal and mantle structure using receiver functions (RF) to image the lithosphere beneath the eastern Sinai subplate, including backazimuth variations. Around 250 teleseismic earthquakes greater than magnitude 6.0 from 2018-2023 are used for our analysis. The obtained receiver functions reveal negative conversions from basin structure, and positive phases from the sediment layer and Moho discontinuity, with backazimuth variations. RF computation is followed by inversion for investigating the shear velocity and Vp/Vs variations across depth, from shallow depths in the crust, extending to deep crust and mantle. An extensive Moho variation under the area is observed by integrating findings from this study and prior investigations. RF and inversion profiles reveal additional insights into seismic boundaries in the crust and mantle beneath the region. The lithospheric architecture beneath the eastern Sinai subplate highlights variations in crust and mantle properties beneath the region, along profiles stretching from north-west to south-east direction beneath the Sinai subplate, and along the strike of the DSF. This work enhances our understanding of the underlying lithosphere beneath the region and offers valuable insights into the evolution of the Sinai subplate and Dead Sea basin zone.