Geophysical Investigations of Ghor Haditha Sinkholes, Jordan

The aim of the geophysical investigations carried out in Ghor Haditha area is to detect the subsurface sinkholes and define their dimensions, delimitation the fresh-saline water interface and predict the scenario of any hazards as well as predicting safe areas and hazardous areas. Three geophysical methods were applied over sinkholes area;Ground Penetrating Radar, Electrical Resistivity Tomography and Time Domain Electromagnetic using NanoTEM technique. Resistivity and GPR surveys show that all subsurface sinkholes are accompanied with or above fresh water or fresh water effects. layers seem to be shapeless or crumbled as an effect of fresh water that swept through them. An important fact is that, all detected subsurface sinkholes were accompanied with fresh water and no sinkholes exist in dry areas. It seems that, the mechanism of subsurface sinkholes formation in the area is depending on the fresh water presence. Results and analysis of geophysical studies show that, the source of fresh water is mainly rain water passing through streams such as Wadi Ibn Hammad, and secondly from irrigation water.Fresh water flowing westwards to the Dead Sea. The interface between fresh and saline water is the boundary between the safe zone and vulnerable zone.