1887

Abstract

Hazardous sinkholes started to appear in alluvial fans and unconsolidated sediments along the Dead Sea coast in 1990, when a small group of sinkholes 2 to 15m in diameter and up to 7m deep were formed in alluvial sediments in and around the middle of the main asphalt road close to Neve Zohar. Since then hundreds of sinkholes have appeared along the western coast from the Attraction Beach in the north to Nahal Hamar to the south of the Dead Sea. There are currently three theories explaining the sinkhole forming mechanism in the Dead Sea region. This could be a pseudo-sinkhole phenomenon (piping) for alluvial fan gravel holes, or mass mobilization and suspended clay transfer hypothesis for mud holes or salt layer dissolution mechanism. However, while none of these explains the sinkhole phenomenon completely, all the investigators agree that sinkhole formation is a dynamic process. It follows in time and could be accompanied by variation of the medium properties (density), salt layer or saline clays dissolution and/or fines washing out and transfer. The presence of fresh or salty groundwater plays an important role in sinkhole formation. Numerous geophysical investigations carried out in recent years were mainly aimed at detecting the sinkholes formation mechanism at depths of tens meters (salt layers, fresh water and large voids detection). In the present study we have used geoelectric methods to achieve a better understanding of the subsurface geoelectric structure at the sinkhole development sites, taking into account that electric parameters (such as resistivity or conductivity) are very sensitive to medium properties and their variations in time, for example, high porosity or voids including medium manifests the same as a high resistivity anomaly zone. In contrast, the water (different degree of salinity) as well as zones including clay appear as low resistivity anomalies. First, we reinterpreted previously obtained and published results of geoelectric surveys at the Neve Zohar, Nahal Hever southern and Ein Gedi Holiday Village sinkhole development sites. We then performed geoelectric mapping of the Ein Gedi Holiday village and palm tree plantation areas using the Continuous Vertical Electric Sounding (CVES) method (Ezersky, 2002) .

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201406217
2002-09-08
2020-05-26
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201406217
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error