The Dead Sea is nearly 10 times more salty than the ocean because water evaporates, leaving behind salt that accumulates in the water and is deposited on the lake bottom.
The Dead Sea is one of the saltiest seas on the planet. Essentially an inland lake instead of a sea, the Dead Sea lies between Jordan, Israel, and Palestine. The complete absence of fish, birds or plants is proof that this is truly an unsuitable place for living creatures, according to IFL Science.
The Dead Sea is so salty because it is fed by the Jordan River but has no outlet, meaning the water can only escape by evaporation, leaving behind minerals and salts. Therefore, the Dead Sea becomes increasingly salty over time as salt accumulates. Currently, it is estimated that this sea is 9.7 times saltier than the ocean.
Increased salinity due to human activity causes less water from the Jordan River to the Dead Sea. Under the impact of dams and agricultural diversions, the amount of fresh water available to dilute saltwater lakes gradually decreases. The problem is exacerbated by the heat in the region and mineral springs along the Dead Sea banks due to tectonic activity.
The Dead Sea is the second saltiest lake in the world, second only to Gaet’ale pond located in the Danakil basin, Ethiopia. This pond has a salt concentration of 43.3%, higher than the Dead Sea’s 34%. For comparison, the average salt concentration in the ocean is 3.5%.
Extremely high salinity makes Dead Sea water look like olive oil mixed with sand, according to NASA’s Earth Observatory. Any object that enters it can float easily. The Dead Sea’s water level is also falling at a rate of about 1.2 meters per year due to human activity, making it infinitely saltier.
The Dead Sea Observatory found that corresponding to rising salinity, salt at the bottom of the lake is being deposited, creating a layer of salt that grows several centimeters thick each year. This happens through a process called double diffusion convection, in which hot water sinks to a cooler lower layer and loses its ability to contain salt as it cools. Instead, salt accumulates in crystalline form. The process occurs relatively quickly because the Dead Sea is already at a critical level in terms of the amount of salt that can be saturated in water.
The only living things that can be found in the Dead Sea are microorganisms. Since the 1930s, scientists have known that the Dead Sea is not completely absent of life. This is the home of microorganisms that exist at a density of about 1,000 – 10,000 archaea/milliliter. In 1992, the salt-loving algae Dunaliella parva bloomed on the lake’s surface, likely due to rainwater. Although D. parva is a green algae, the phenomenon that turns the Dead Sea water red is due to the high concentration of bacterioruberin protein.