The oceans occupy 2/3 of the surface of our planet. It is distinguished among other factors by the increased salinity of the water. This indicator depends on the content of dissolved substances in 1 kg of liquid. There are more than 50 of them. This indicator is expressed in ppm (‰). This is a tenth of a percent.
On average, on the surface of the ocean, salinity is 32-37 ‰. If you go deeper into the living environment of most living things, then this indicator can be fixed at around 34-35 ‰. But not in all seas the same level of the presented indicator is noted. The salinity of the Red Sea significantly exceeds this level. There are several explanations for this phenomenon. Everyone will be interested to know about them.
General information
Examining the topic, it is first necessary to remember where the Red Sea is located on the world map. This pond is located between the Arabian Peninsula and Africa. Its length from southeast to northwest is 1932 km. The width of the sea is 280 km. The area of the Red Sea is 460 thousand km².
The average depth is determined at the level of 437 m, and the deepest place reaches 3039 m. This sea belongs to the basin of the Indian Ocean, with which it is connected by the narrow strait of Bab el-Mandeb. In the north there is a connection through the Suez Canal with the Mediterranean Sea.
The width of the channel of communication between the sea and the Indian Ocean is very small (only about 26-120 km). Therefore, the hollow in which the represented reservoir is located is considered the most isolated in the basin. The Red Sea is considered one of the youngest.
Bottom relief
When considering the Red Sea on a world map, attention should also be paid to its relief. The shelf stands out clearly here. Its width increases from north to south. At a depth of 120-200 m, the shelf passes into a steep ledge on the slope of the mainland. This is the main gutter. It is located at a depth of 500 to 2, 000 km.
The underwater relief is rich in mountain ranges, ridges and a series of steps. A narrow deep fault passes along the axis of the depression. This is an axial trough. In the 60s, in its central part (a depth of about 2 thousand km), scientists discovered several deep brines. Their composition is unique.
Brines appeared due to underwater tectonic activity. In more than 15 hollows of the axial trench, many underwater mineral springs with salinity of more than 250 обнаружено are now found. This fact also has a certain effect on the composition of the water of the Red Sea.
Climate of the reservoir
The peculiar weather conditions also affect the salinity of the Red Sea. It is located in a continental tropical climate. Therefore, high air temperatures prevail here, which varies in accordance with the season.
Over the northern part is somewhat colder. In winter, it averages +15 ° С here, and in summer +27 ° С. In the south, at the same time, this indicator reaches +20 ° С in January and +32 ° С in August.
Rainfall over the sea can be described as low. This figure does not exceed 50 mm per year. Rains most often occur in the form of showers. The amount of evaporation per year is about 200 mm. Such a high evaporation of water is also an important factor in increasing salinity.
Storm activity is quite low. It increases in the winter. More often storms occur in the northern part of the reservoir.
Water exchange and hydrocirculation
Studying what explains the high salinity of the Red Sea, it is worth paying attention to its water exchange. This factor also explains the increased level of salinity. It should be noted that not a single river flows into the Red Sea. Water exchange occurs only through channels of communication with the Indian Ocean and the Mediterranean Sea.
About 1-1.3 thousand km flows through the Bab el-Mandeb Strait. cube water. This figure exceeds the amount of water flowing through the Gulf of Aden. The remainder is spent on evaporation. Also, these waters make up for the negative value of fresh balance.
This is a closed structure, which is built on the processes of interaction with the atmosphere. The wind forms summer and winter water circulation. This, in turn, determines the conditions for the flow of water from the Gulf of Aden. These masses affect the upper layers of the reservoir. Due to the current situation, the distribution of hydrological characteristics in the north is quite uniform. In the south, a complex structure of water masses arises.
Salinity
The distribution of salinity in the Red Sea is explained by the processes occurring in it. In the south, due to hydrothermal processes, this figure is lower - 36 ‰. But in the northern regions it reaches 42 ‰.
The waters of the Gulf of Aden are warmer and less salty. They move in the upper layers from south to north. In winter, they are found with colder and salty waters of the Red Sea.
In the intermediate water layer at a depth of 200-500 m, relatively constant indicators of salinity and temperature are determined. Both in the north and in the south, this figure is 40-40.5 ‰.
The deep layer is formed in the process of convective motion of water masses. It is determined at a level of 500 m and below. Here the water temperature is quite high. It reaches +22 ° C, and its salinity is more than 40 ‰. Deep masses are moving south. Mineral brines are determined in these layers. Their effect on water layers has so far been little studied.
Convective mixing
The density of water in the Red Sea changes as a result of cooling and heating of the masses in winter and summer. This is called convective motion. Heated water has a lower density. It rises, displacing the colder and denser masses in depth.
This process is accompanied by good mixing of water in the sea. In almost all depths and territories, salinity is characterized by uniformity. Underwater tectonic faults generate heat and salty streams in the bowels of the sea. Therefore, the reservoir is heated in the bottom areas. It also promotes convective mixing of the masses.
The above features of the presented water system explain why the Red Sea is the most saline among all water bodies of the World Ocean.
Why is the water salty?
As mentioned above, deep water shows the highest salinity of the Red Sea (in percentage these masses make up 75 parts of the total volume of the reservoir). This is a pretty high rate. Summarizing all the above, several reasons for this phenomenon should be noted.
Evaporation from the surface of the water due to the large area of the sea is quite large. At the same time, salts and other chemical elements remain in place. Only fresh water enters the atmosphere. A hot climate also contributes to increased evaporation.
Due to the lack of rivers flowing into the sea, as well as its insufficient communication with other water bodies of the World Ocean, desalination is characterized by a negative indicator.
The rainfall in the Red Sea is very low. Therefore, rainwater also cannot desalinate water masses.
How does salinity affect water
The water of the Red Sea is unique. Due to the absence of strong storms, rains, river flows, it is characterized by high transparency. Its bright blue color attracts divers from all over the world.
Unlike the Dead Sea, life is in full swing here. Many fish, shellfish, algae and corals have adapted to similar conditions. The diversity of species in the Red Sea is very large.
Special climatic conditions allow the sea to maintain almost always a constant water temperature and salinity level. This allows living organisms to actively develop in these waters.
