The configuration of the fresh–saline groundwater interface within the regional Judea Group carbonate aquifer in northern Israel between the Mediterranean and the Dead Sea base levels as delineated by deep geoelectromagnetic soundings

Abstract

A combined high resolution short offset transient electromagnetic (SHOTEM) and deep sounding, long offset (LOTEM) survey has been carried out along two traverses between the Mediterranean Sea and the Jordan-Dead Sea Rift (DSR). The DSR is located in the study area some 200–250 m below sea level. The measurements detected a deep conductor, the top of which exhibited a regular behavior along the both traverses, declining from the Mediterranean to the DSR base level. The geometry of this geoelectric boundary coincides fairly well with the configuration of a supposed fresh/saline groundwater interface as also obtained by both numerical and physical modeling for the known hydrogeological conditions in the study area. Therefore the detected geoelectric boundary is identified with the interface, supporting the hypothesis of current seawater intrusion into the deep regional aquifers between the Mediterranean and the DSR base levels. The intrusion causes the salination of fresh groundwater within the aquifers as well as the salination of the Sea of Galilee.