The length of the sea is 47 m., and its maximum breadth is about 9½ m.; its area is about 340 sq. m. It lies nearly north and south. Its surface being 1289-1300 ft. below the level of the Mediterranean Sea, it has of course no outlet. It is bounded on the north by the broad valley of the Jordan; on the east by the rapidly rising terraces which culminate in the Moabite plateau, 3100 ft. above the level of the lake; on the south by the desert of the Arabah, which rises to the watershed between the Dead and the Red Sea--65½ m. from the former, 46½ from the latter; height 660 ft.--and on the west by the Judean mountains which attain a height of 3300 ft. On the east side a peninsula, El-Lisan ("the tongue"), of white calcareous marl with beds of salt and gypsum, divides the sea into two unequal parts: this peninsula is about 50 ft. high, and is connected by a narrow strip of marshland with the shore. Its northern and southern extremities have been named Cape Costigan and Cape Molyneux, in memory of two explorers who were among the first in modern times to navigate the sea and succumbed to the consequent fever and exhaustion. North of the peninsula the lake has a maximum depth of 1278 ft.; south of it the water is nowhere more than 12 ft., and in some places only 3 ft. The surface level of the lake varies with the season, and recent observations taken on behalf of the Palestine Exploration Fund seem to show that there are probably cyclical variations also (ultimately dependent on the rainfall), the nature and periodicity of which there are as yet no sufficient data to determine. In 1858 there was a small island near the north end rising 10 or 12 ft. above the surface and connected with the shore by a causeway; this has been submerged since 1892; and owing to the gradual rise of level within these years the fords south of the Lisan, and the pathway which formerly rounded the Ras Feshkhah, are now no longer passable.
The slopes on each side of the sea are furrowed with watercourses, some of them perennial, others winter torrents only. The chief affluents of the sea are as follows:--on the north, Jordan and 'Ain es-Suweimeh; on the east Wadis Ghuweir, Zerka Ma'in (Callirrhoë), Mojib (Arnon), Ed-Dera'a, and el-Hesi; on the west, Wadis Muhawat and Seyal, 'Ain Jidi (En-Gedi), Wadi el Merabbah, 'Ain Ghuweir, Wadi el-Nar, 'Ain Feshkhah. The quantity of water poured daily into the sea is not less than 6,000,000 tons, all of which has to be carried off by evaporation. The consequence of the ancient evaporation, by which the great Pleistocene lake was reduced to its present modest dimensions, and of the ceaseless modern daily evaporation, is the impregnation of the waters of the lake with salts and other mineral substances to a remarkable degree. Ocean water contains on an average 4-6% of salts: Dead Sea water contains 25%. The following analysis, by Dr Bernays, gives the contents of the water more accurately:--