The Dead Sea minerals

The saltiest water most people will ever float in, and half of Britain's wartime potash came out of it.

The Dead Sea lies in the endorheic basin of the Jordan Rift Valley, fed mainly by the Jordan River. As of 2025 its surface sits 439.78 metres below sea level, which makes its shores the lowest land on Earth, and at 304 metres deep it is the deepest hypersaline lake in the world. The US Geological Survey records a potassium prospect on the Jordanian side under the name Aghwar.

The chemistry is genuinely strange. Salinity measured 342 grams per kilogram, about 34 per cent, roughly 9.6 times as salty as the ocean, at a density of 1.24 kilograms per litre, which is why floating is effortless. More telling is what the salt is made of. Measured as anhydrous chlorides by weight it runs magnesium chloride 50.8 per cent, sodium chloride 30.4, calcium chloride 14.4 and potassium chloride 4.4. Ordinary seawater salt is about 85 per cent sodium chloride. Sulfate here is very low and bromide is the highest of any water on Earth.

People have taken products out of it for a very long time, from asphalt for Egyptian mummification to potash for fertiliser. The Palestine Potash Company supplied half of Britain's potash during the Second World War, and both its plants were destroyed by the Jordanians in the 1948 war. The Dead Sea Works was founded on the remnants in 1952 as a state enterprise, privatised in 1995, and by 2001 was producing 1.77 million tons of potash and 206,000 tons of elemental bromine a year.

The lake is disappearing as you read this. Its surface area is now 605 square kilometres, down from 1,050 in 1930, and schemes to slow the loss, including the Red Sea to Dead Sea Water Conveyance, have been proposed and scrapped.

Look south along the shore for Mount Sodom, a halite formation standing 210 metres tall.