|MadSci Network: Earth Sciences|
Why is the Dead Sea so salty? Why does it have a sulphur like odour?
The Dead Sea is salty because it has no outlets. Any minerals which flow into it stay there. All bodies of fresh water have outlets which allow them to dispose of dissolved minerals which flow into them from their sources. Oceans and seas typically have no outlets (although there are exceptions; the Mediterranean Sea is saltier than the Atlantic Ocean, and loses mineral-laden water by a deep outflow layer through the Straits of Gibraltar).
This "no-outlet" condition is general with all landlocked bodies of salt water, such as the Great Salt Lake in Utah, USA, or the Caspian Sea. Saltiness can be aggravated, as it is in the Dead Sea or the Great Salt Lake, by location in a hot, dry climate.
The sulfur odor (note the American spelling I am using!) comes from dissolved, reduced sulfur in the water and is probably a property of the feedwater. Does the Jordan River smell of sulfur as well? Does it flow through swamps? My Palestinian geography is not what it should be.
The drinking water in my home in northwestern Ohio, USA, smells of sulfur as well, because the area in which I live used to be the Great Black Swamp. Swamps in general are hotbeds of reduced materials like methane ("swamp gas") and peat, so that any source of sulfur in a swamp will likely be in chemically reduced form; hence the strong odor of sulfur in our drinking water.
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