One of the world's most famous bodies of water, due to its unique characteristics, is the Dead Sea. It's famous for several reasons. First, its extremely high salt content prevents life from developing in its waters and allows other objects to float. It's also well-known because it's mentioned in several passages of the Bible. Despite being called the Dead Sea, it's an endorheic lake with no outlet.
In this article we are going to tell you about all the characteristics, geology and curiosities of the Dead Sea.
Key features
The Dead Sea is an endorheic lake, completely surrounded by land with no outlet to the open air. It is a hypersaline lake with a high salt concentration, exceeding that of any sea or ocean. Located on the borders of Jordan, Israel, and the West Bank, it lies approximately 400 meters below sea level, which may explain its extremely high salinity.
If we analyze it from a perspective, we can see that the Dead Sea is one of the lowest points on Earth. That is, it is the lowest body of water of all. It is divided into two basins separated by a land bridge. The entire basin sits on a depression created by a rift or fault known as the Jordan Valley. This is located between the Judean Hills and the Transjordanian Plateau.
The northern part of the Dead Sea is the largest and deepest. It stretches for about 50 kilometers and reaches depths of up to 400 meters . The southern basin, on the other hand, is only 11 kilometers long and a mere 4 meters deep. The only river that flows into this lake is the Jordan River, which is its only continuous tributary. It typically discharges a large amount of freshwater, especially into the northern basin. If you're interested in the geography of the river, you can read more in the history of the Jordan River.
In the southern part, it is usually fed by water from various streams. But this is not a significant contribution. This means that the Dead Sea level does not fluctuate throughout the year. The high salt content amounts to approximately 340 grams per liter. One of the factors that contributes to the high salt content is that the amount of fresh water it receives is less than the amount of water that evaporates. Furthermore, it is important to consider why seawater is salty, which is closely related to its mineral content.
In this case, we have a very high rate of seawater evaporation. This is because it is located in an area with high temperatures and little rainfall. The salts found in this water are sodium chloride, magnesium chloride, calcium chloride, potassium chloride, and magnesium bromide. It can be said that approximately 27% of the water in this sea is composed of solid substances.
Formation of the dead sea
As we mentioned before, the Dead Sea is situated on a tectonic rift. That is, it is a depression bordered by parallel faults. This fault extends along the African and Arabian tectonic plates. Before this rift formed, the Mediterranean Sea was much larger than it is now. It covered all of Palestine during the Jurassic and Cretaceous periods . However, in the Miocene , the Arabian Plate collided with the northern part of the Eurasian Plate. This is how the land began to rise, and the central mountain range of Palestine was formed. Gradually, over the years, the tectonic rift formed and filled with seawater.
Already in the Pleistocene, there was a large amount of land between the Mediterranean and the valley that was formed because of the crack between the tectonic plates. It was possible to raise several meters until the sea water was withdrawn. This caused the pit and the waters to be isolated. The Gulf of Aqaba was also isolated.
Biodiversity of the Dead Sea
As we have mentioned before, the salinity of the Dead Sea is very high. It becomes about 10 times the salinity of the ocean. This makes it practically a marine desert in which only some living beings are capable of inhabiting it. The only living beings capable of surviving in these extreme conditions are bacteria, protozoa, and single-celled algae.
Most of these algae belong to the genus Dunaliella. However, along the entire shoreline of the Dead Sea, we can find some halophytic plants. These plants are adapted to areas with high concentrations of salinity or alkalinity. Conversely, we cannot find any type of fish, reptiles, amphibians, and certainly no mammals. Occasionally, some fish are carried by the river currents and end up dying without any chance of survival.
Therefore, we cannot speak of biodiversity when referring to the Dead Sea. However, this does not mean that this sea lacks valuable resources. Thanks to its high salinity, its salts can be extracted for therapeutic purposes. The mud found on the seabed can also be applied to the body, as it has numerous beneficial properties due to its mineral content.
Threats
Although this sea is not overfished, its size and volume have been decreasing over the last few decades. This is mainly due to water diversions and significant land subsidence, which has led to the collapse of some surrounding areas. A reduction in the total water volume has been observed since 1960. This began when Israel established a pumping station on the shores of the Sea of ​​Galilee. This pumping station diverted water from the Jordan River to other countries that used it for drinking water and irrigation.
The diversion of large amounts of water from its main tributary, coupled with significant evaporation, is causing the volume of water in this sea to steadily decrease. The water level is receding by approximately one meter per year. You can read more about the effects of its disappearance in the article "Humanity and Climate Change ."