Salty Fingers Mystery


For decades, the Dead Sea eluded our understanding: Formation of 'salty fingers' does not defy the laws of physics, the study explains

Research from 2019 detailed the formation of salt structures on the bottom of the Dead Sea. They are increasing every year.

Salt crystals are slowly accumulating at the bottom of the Dead Sea, according to 2019 research. Located in Jordan, this sea is considered to be the saltiest sea to be found on Earth. It has been a major attraction for people for thousands of years, due to its supposed healing properties.

Since the Dead Sea is saltier than normal seawater, it also has a higher density and therefore more buoyancy. In recent decades, the sources of freshwater that replenished the Dead Sea have also gradually disappeared, making it even saltier. As early as 1979, however, scientists noticed that salt crystals began accumulating on the sea’s bottom. This layer increases by approximately 10 centimeters every year, explains the AGU portal.

The peculiarity of this process was until 2019 fact that the process of snowing crystals to the bottom of the sea was against the laws of physics. But a study by the authors from this year proved that the accumulation of salt at the bottom of the Dead Sea is not a process that would rebel against nature. In their work, they described the formation of "salty fingers" that slowly help the salt sink to the bottom of the sea.

On the one hand, the study helps to better understand how the Dead Sea works, but on the other hand, they also gain invaluable knowledge about how massive deposits of salt are deposited in the earth's crust. As the study's authors explain, the Dead Sea is the only body of water on Earth where the process of forming salt crystals occurs. That is why they consider it a unique laboratory in which they can take a closer look at how these mechanisms operate.

Solving the mystery

As mentioned earlier, the Dead Sea becomes saltier over time, so some salt began concentrating near the surface. During the summer months, the Sun heats the surface of the sea and separates it into two distinct layers. The upper layer is warmer, and the cold layer is held at the bottom. During the summer, the water in the warmer layer evaporates and becomes saltier than in the lower layer.

However, this did not explain why the salt from the higher layer mixed with the cooler one, since the two layers do not mix. The explanation came in a study from 2016, which they tested in practice only three years later. According to this theory, small particles can reach the cooler layer when the water level is disturbed. The heat dissipates faster than the salt, so the salt separates and forms crystals that sink to the bottom of the sea.

In 2019, a study using computer simulation confirmed the correctness of the theory of salty fingers. The authors managed to demonstrate the flow of salt to the bottom of the sea and the creation of salt deposits in the middle of it. Using this model, scientists can better explain the formation of salt deposits in the earth's crust, which can reach a thickness of up to one kilometer. However, the process of their formation has not been scientifically described.