Crustal and upper mantle structure across the Dead Sea rift and Israel from teleseismic P-wave tomography and gravity data

Abstract

New findings of the structure of the crust and the upper mantle across the Dead Sea rift and Israel were obtained by applying P and PKP wave relative travel time residuals inversion of 612 teleseisms, recorded by the seismic networks in Israel and Jordan. Independently of the relative teleseismic travel time residuals, the Bouguer gravity anomalies were used as an additional aid to examine the structure of the crust and upper mantle. An examination of the teleseismic travel time residuals in Israel suggests the existence of two prominent provinces of distinct crustal structure. The northward increase of the teleseismic travel time residuals is in good agreement with a gradual thickening of the sedimentary sequence and a simultaneous thinning of the crust. Examination of the inverted velocity anomalies indicates that the upper and lower crusts are sub-divided into a number of structures. We identify several velocity anomalies that are associated with prominent geological structures. The southern Dead Sea basin is characterized with the largest decrease of velocity, in both upper and lower crustal layers, due to the infilling of light material relative to the surrounding material. The velocity anomaly in the Carmel structure is probably associated with variations in the upper part of the upper mantle. Examination of a cross-section that traverses the Dead Sea transform supports the existence of lighter mass density material on the eastern side relative to that on the western side.