Application of the marine time-domain electromagnetic method in lakes: The sea of Galilee, Israel

The proposed surface-marine time-domain electromagnetic (TDEM) system has been applied in the Sea of Galilee ( Lake Kinneret) to trace the distribution of subbottom saline groundwater which poses a threat to the quality of the lake water. Eight marine profiles, accompanied by a number of supplementary onshore TDEM soundings, have been carried out throughout the lake to investigate the situation. A very low-resistivity layer (less than 1 ohm-m), which can undoubtedly be identified as highly saline groundwater, has been detected in all onshore and offshore measurements, except for those carried out in the north-western part of the lake. The depth to the top of the low-resistivity layer varies from a few tens of metres to about 100 metres below the lake floor.