Seismic discontinuities in the lithospheric mantle at the Dead Sea Transform

Abstract

SUMMARY The Dead Sea Transform (DST) was formed in the mid-Cenozoic, about 18 Myr ago, as a result of the breakaway of the Arabian plate from the African plate. Higher resolution information about the sub-Moho structure is still sparse in this region. Here, we study seismic discontinuities in the mantle lithosphere in the region of the DST using a modified version of the P- and S-receiver function methods. We use open data from permanent and temporary seismic stations. The results are displayed in a number of depth profiles through the study area. The Moho is observed on both sides of the transform at nearly 40 km depth by S-to-p and in P-to-s converted signals. The lithosphere–asthenosphere boundary (LAB) on the eastern side of the DST is observed near 180–200 km depth, which is according to our knowledge the first LAB observation at that depth in this region. This observation could lead to the conclusion that the thickness of the Arabian lithosphere east of the DST is likely cratonic. In addition, we observe in the entire area a negative velocity gradient at 60–80 km depth, which was previously interpreted as LAB.