The thermal structure of Israel and the Dead Sea Fault

In this paper we analyze temperature data from all the available oil and water wells in Israel and compare the results with seismicity depth and with heat flux estimation from xenoliths. We show that the average heat flux in Israel is 40-45mW/m², consistent with measurements of the Arabian Shield. A heat flux anomaly exists in Northern Israel and Jordan. This could be attributed to groundwater flow or young magmatic activity (~100,000years) that is common in this area. A higher heat flux exists in Southern Israel and Jordan, probably reflecting the opening of the Red Sea and the Gulf of Eilat (Gulf of Aqaba) and does not represent the average value present in the Arabian Shield. The temperature gradient at the Dead Sea basin is relatively low, resulting in low heat flux (<40mW/m²) and a relatively deep seismicity extending to lower crustal depths, in agreement with earthquake depths (<25-30km). Higher heat fluxes at the Sea of Galilee (70mW/m²) and at the Gulf of Eilat (65mW/m²) results with shallower seismicity (<10-12km). The steep geothermal gradients yielded by xenoliths (>80mW/m²) could be the result of local heating by magmas or by lithospheric necking and shear heating.