What is the Dead Sea?

(English name: Dead Sea) Arabic is al-Bahr al-Mayyit, and Hebrew is Yam ha-Melah (meaning "salt sea"). The inland salt lake between Israel and Jordan is the lowest water area on the earth, with an average of about 400 meters (1, 3 12 feet) below sea level. The northern half belongs to Jordan; The southern half is divided between Jordan and Israel. However, after the 1967 Israeli-Arab war, the Israeli army has been occupying the whole West Bank. The name comes from the salt-rich Dead Sea and its coast. In such water, aquatic organisms such as fish are difficult to survive, and there are only bacteria and no living things in the water; There are no flowers and plants growing on the shore and around it, so people call it the "Dead Sea". The name of the Dead Sea can be traced back at least to the Hellenistic era (32330 BC). Since the time of Abraham (the ancestor of the Hebrews) and the destruction of Sodom and Gomorrah (according to the Old Testament, these two cities were burned by skyfire because of their heinous crimes; Because the former sites of these two cities may have sunk into the Dead Sea, the Dead Sea has been linked with biblical history. The dry lake and river provided shelter for David (King of Israel) and Herod I (King of Judaism). Herod I shut himself up in Masaadeh Castle when the rest of the people besieged Jerusalem in 40 BC. Mechada Castle was besieged for three years. Finally, in 73 AD, its Jewish fanatics committed suicide collectively and the castle was destroyed by the Romans. The Jewish Sect that left the Bible manuscript, now called the Dead Sea Scrolls, once hid in a cave in the northwest of the lake. Geographical location and water scale The Dead Sea is located at the lowest point of the Jordan-Dead Sea Trench (560 km [350 miles] long) and is the northern continuation of the Great Rift Valley in East Africa. This is the sinking crust sandwiched between two parallel geological fault cliffs. Seen from the lake, the eastern cliff along the edge of Moab Plateau is clearer than the western cliff, showing the characteristics of Jewish uplift with small slope. The Dead Sea is an inland salt lake located in the Jordan Valley between Israel and Jordan. The West Bank is the Jewish Mountain, and the East Bank is the Outer Jordan Plateau. The Jordan River flows from the north. Jordan River injects 540 million cubic meters of water into the Dead Sea every year. In addition, four small rivers with water all the year round are injected from the east. Due to the large evaporation in summer and water injection in winter, the water level of the Dead Sea changes seasonally, ranging from 30 to 60 cm. The Dead Sea is 80km long and18km wide, with a surface area of about1020km2, an average depth of 300m, and the deepest point of 415m. Lisan Peninsula in the east of the lake divides the lake into two lake basins of different sizes, with an area of three quarters in the north and a depth of 4 15m, and an average depth of less than 3m in the south. There is no water outlet, and the water inflow mainly depends on the Jordan River, which is roughly equal to evaporation. It is one of the natural water bodies with the highest salinity in the world. Because the Dead Sea is located on the disputed border between Jordan and Israel, it has not been used for navigation on a large scale. The lakeshore is barren and there are few long-term settlements. There are only Sedom's factory and several hotels and hot spring resorts in Kalia, and there is also a Kibbutz (Israeli agricultural community) in the' En Gedi area in the west. Occasionally a small piece of cultivated land can be seen on the shore of the lake. Geomorphological features The Dead Sea is located at the lowest part of the Jordan-Dead Sea Trench, which is the northern continuation of the Great Rift Valley in East Africa. This is the sinking crust sandwiched between two parallel geological fault cliffs. The Dead Sea formed in the rift valley, like a huge catchment basin. It is said that Sodom and Gomorrah in Sin City, which were destroyed by God in Genesis, sank at the bottom of the South Dead Sea. No wonder the water is shallow in the south and deep in the north. The water level of the Dead Sea is about 400 meters below sea level, which is the lowest point on the earth's surface. The West Bank is the Jewish Mountain, and the East Bank is the Outer Jordan Plateau. The Jordan River flows from the north. The Dead Sea is 80 kilometers (50 miles) long and 18 kilometers (1 1 mile) wide, with a surface area of about 1 0,020 square kilometers (394 square miles) and a deepest point of 400 meters (1 1,300 feet). AL-Lisan Peninsula in the east of the lake divides the lake painting into two lake basins with different sizes and shades. The northern part is large, accounting for about 3/4 of the total area of the lake, with a water depth of 400 meters; The south is small and shallow (less than 3m on average [10ft]). Before the biblical era and the 8th century BC, only the northern lake basin was inhabited. At that time, the lake was about 35 meters (1 15 feet) lower than the level at the end of the 20th century. 1896, the lake rose to the highest water level (389 meters below sea level [1, 275 feet]). After 1935, the lake fell again. Climatic characteristics The Dead Sea is located in the desert, with little and irregular rainfall. The annual rainfall of Lisan Peninsula is 65mm. The climate is warm in winter and hot in summer. The average annual evaporation of the lake is 1400 mm, so the lake often forms dense fog. The water level of the lake changes with the seasons, ranging from 30 to 60 cm. The upper water temperature of the lake is 19-37℃, the salinity is lower than 300‰, and it is rich in sulfate and bicarbonate. The bottom water temperature is 22℃ and the salinity is 332‰, which is rich in sulfide, magnesium, potassium, chlorine and bromine. Its bottom is full of sodium and chloride. There are chemical plants and saltworks in Jingtian on the south bank. It is said that the Dead Sea is not frozen in winter, and it is very hot in summer, which causes the lake surface to evaporate about 1400 mm every year, and the lake surface often fogs. The temperature of the Dead Sea is very high, and almost all the water (4-6.5 billion liters per day) flowing into the Dead Sea from the Jordan River has dried up, leaving more salt. The Dead Sea lies in the desert. Rainfall is small and irregular. The annual rainfall in Lisan Peninsula is about 65 mm (2.5 inches), while the annual rainfall in Sedom (the city near the historic city of Sodom) is only about 50 mm (2 inches). Due to the low altitude and the shelter of the lake, the climate in winter is warm and pleasant. In June, 5438+ 10, the average temperature in the southern end of Jingtiancheng 17℃(63℉) and the northern end 14℃ (58 ℉). There is no ice in the lake. It is very hot in summer. In August, the average temperature in Jingtian City was 34℃(93℉), and the highest record reached 565,438+0℃ (65,438+024 ℉). Evaporation of lake water-it is estimated that the average annual evaporation is about 1 1,400 mm (55 inches)-often forms dense fog on the lake surface. The atmospheric humidity on the river ranges from 45% in May to 62% in 10. There is often a breeze on the lake and land. During the day, the wind blows in all directions on the lake, and then blows to the center of the lake in turn at night. Water comes from the Jordan River, with a large amount in winter and spring, averaging 540 million cubic meters (65.438+0.9 billion cubic feet) per year. Four small rivers that flow all the year round descend from Jordan and pass through deep valleys in the east: Al-Uzaymi, Zarqa Main, Al-Mawjib and Al-Hasa. Rivers from many other rivers sometimes flow in from neighboring highlands or Arabian valleys in a short time. Sulfur-bearing hot spring water is also injected into the river. Due to the evaporation of lake water in summer, especially the inflow of river water in winter and spring, the water level of lake water varies seasonally, ranging from 3060 cm (1224 inch). The salt content of unique seawater dead seawater is extremely high, and the higher it goes to the bottom of the lake, the higher it is 10 times than that of ordinary ocean. The deepest part of the lake has been petrified (generally, the salt content of seawater is 35 per thousand, while the salt content of the Dead Sea is about 230 to 250 per thousand). The salt content of surface water is 227-275g per liter, and that of deep water is 327g. )。 Because of the high concentration of salt water, swimmers are easy to float. There are no other animals and plants in the lake except bacteria. Fish from Jordan or other small rivers will die immediately at high tide. Coastal plants are mainly halophytes adapted to saline-alkali land. The Dead Sea is a huge salt storage area. The coast of the Dead Sea is barren, there are almost no fixed settlements, and occasionally there are small plots of cultivated land and health resorts. Sodium chloride saturated in deep water precipitates into petrochemical products. Because of the high salt content in the lake, swimmers can easily float. Generally, the salt content of seawater is 35 per thousand, and that of the Dead Sea is about 230 to 250 per thousand. In surface water, the salt content per liter is 227 to 275 grams, so the Dead Sea is a large salt reservoir. It is estimated that the total salt content of the Dead Sea is about 654.38+0.3 billion tons. But in recent years, scientists have found that there are green algae and bacteria in the sediments at the bottom of the Dead Sea Lake. The lake is dark blue, very calm and salty, which makes people unable to sink or swim. Put one arm in the water and the other arm or leg will float. If you want to immerse yourself in the water, you should gradually tilt your back until you lie flat. The salt content of the water in the Dead Sea is extremely high, and the salt content increases as it reaches the bottom of the lake. There are actually two different water masses in the lake. From the water surface to the depth of 40m (130ft), the water temperature ranges from 1937℃(6698℉), the salt content is slightly lower than 300, and the water is rich in sulfate and bicarbonate. After the transition zone of 40 100 m (130330 ft), the temperature of the lower water remains unchanged, about 22℃(72℉), and the salt content is higher (about 332%), including hydrogen sulfide and high concentrations of manganese, magnesium, potassium, chlorine and bromine. In deep water, saturated sodium chloride precipitates to the bottom of the lake. The water below has been petrified (that is, it is very salty and thick and has been at the bottom of the lake for a long time); Sheung Shui is the ancient water in the last centuries after the biblical era. Because of the high concentration of salt water, swimmers are easy to float. The fresh water of the Jordan River remains on the surface; In spring, the color of mud can be seen as far as 50 kilometers (30 miles) south of the entrance of the river into the Dead Sea. Because of the high salt content, there are no animals and plants except bacteria. As soon as the water rises, the fish flowing out of the Jordan River or the small river will die immediately. Except for the vegetation along the river bank, the only plants are intermittent, mainly halophytes (plants growing in saline-alkali land). The Dead Sea is a huge salt storage area. Salt is mainly stored in Jingtian Mountain on the southwest coast. Since ancient times, a small amount of salt has been mined here. 1929, a potash fertilizer plant was opened in Kaliya, the mouth of the Jordan River. Later, auxiliary facilities were established in Sedom. In the Israeli-Arab war of 1948 1949, the factory in Kalia was destroyed. Dead Sea Factory Co., Ltd. established a factory in Jingtian on 1955 to produce potassium carbonate, magnesium chloride and calcium chloride. Another factory produces bromine and other chemical products.