Digital topography and bathymetry of the area of the Dead Sea Depression

Abstract

The Dead Sea Depression occupies the central part of that segment of the Syrian-African rift extending from the mountains of southern Lebanon to the Arava Valley north of the Gulf of Aqaba on the Red Sea. The lowest continental feature in the world, it encloses the Dead Sea, whose surface now lies at about −409 m. This shrunken sea consists of a shallow southern basin occupied by evaporation pans, and a northern basin, 50 km in length by 13–17 km in width, with a flat floor some −731 m below MSL. The depression is asymmetric, with the mountains to the east being up to 500 m higher. The closed depression has two outlets, one at 60.5 m altitude into the Mediterranean via the Jezreel Valley near Afula, and a second into the Red Sea at about 200 m altitude in the Arava Valley. A digital terrain model (DTM), based upon the local 1:50,000 scale topographic maps and modern bathymetric surveys, gives elevations to decimeter resolution on a grid with 25 m spacing. When visualized as shaded relief or in coloured hypsometric format, the DTM graphically shows the overall morphology and its many features. These include the local tectonics, from the major boundary faults to the associated subsidiary faults and lineaments, and their possible relationships with the incised canyons offshore. Also clearly visible are the volcanic cones on the Golan heights, the coast-paralleling kurkar ridges, and the halokinetic disruptions to the deep offshore topography. The DTM was used to compute a hypsometric curve for the closed depression from −731 m to +60 m. The maximum area and volume of a lake extending to the Afula ‘spillway’ would be 5985 km 2 and 1602 km 3, respectively. Inflection points were observed at −715 m, where the Dead Sea's flat bottom meets its steep flanks, at −385 m where the northern basin meets the flat floor of the southern basin and surrounding plain, at −228 with the step up to the basin of the Sea of Galilee, and at Mediterranean sea level.