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The Dead Sea (; ) is both the lowest point in Eurasia at 418 metres (1,371 ft) below sea level and falling, and the deepest hypersaline lake in the world at 330 m (1,083 ft) deep and 799 m (2,621 ft) below sea level. It is also one of the saltiest bodies of water on Earth with a salinity of about 30%. This is about 8.6 times greater than the average ocean salinity. It measures 67 kilometres (42 mi) long, up to 18 kilometres (11 mi) wide, and is located on the border between the West Bank, Israel, and Jordan, and lies in the Jordan Rift Valley. The main tributary is the Jordan River. The Dead Sea has attracted interest and visitors from around the Mediterranean basin for thousands of years. It was a place of refuge for King David, it was one of the world's first health resorts for Herod the Great, and it has been the supplier of products as diverse as balms for Egyptian mummification to potash for fertilizers. In Arabic the Dead Sea is called meaning "the Dead Sea", or less commonly Bahr Lūţ meaning "the Sea of Lot". Historically, another Arabic name was the "Sea of Zoar", after a nearby town. In Hebrew the Dead Sea is called the - meaning "sea of salt", or Yam ha-Mavet - meaning "sea of death". In past times it was the "Eastern Sea" or the "Sea of Arava". To the Greeks, the Dead Sea was "Lake Asphaltites" (see below).
Natural history
Climatic features Therapies popular at Dead Sea Chemistry and health effects Until the winter of 1978-1979, the Dead Sea was composed of two stratified layers of water that differed in temperature, density, age, and salinity. The topmost 35 meters or so of the Dead Sea had a salinity that ranged between 300 and 400 parts per thousand and a temperature that swung between 19 °C (66 °F) and 37 °C (98 °F). Underneath a zone of transition, the lowest level of the Dead Sea had waters of a consistent 22 °C (72 °F) temperature and complete saturation of sodium chloride (NaCl). Since the water near the bottom is saturated, the salt precipitates out of solution onto the sea floor. Beginning in the 1960s water inflow to the Dead Sea from the Jordan River was reduced as a result of large-scale irrigation and generally low rainfall. By 1975 the upper water layer of the Dead Sea was actually saltier than the lower layer. The upper layer nevertheless remained suspended above the lower layer because its waters were warmer and thus less dense. When the upper layer finally cooled down so that its density was greater than the lower layer the waters of the Dead Sea mixed. For the first time in centuries the lake was a homogeneous body of water. Since then stratification has begun to redevelop. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride (common salt) with the remainder comprised of various trace elements. The concentration of sulfate, SO42-, ions is very low, and the bromide ion concentration is the highest of all waters on Earth. Chlorides neutralize most of the calcium ions in the Dead Sea and its surroundings. While in other seas sodium chloride is 97% of the salts, in the Dead Sea the quantity of NaCl is only 12-18%. Comparison between the chemical composition of the Dead Sea to other lakes and oceans show that the salt concentration in the Dead Sea is 31.5% (the salinity fluctuates somewhat). Because of its unusually high concentration of salt, anyone can easily float in the Dead Sea because of natural buoyancy as a result of the higher density of the water. In this aspect, the Dead Sea is similar to the Great Salt Lake in Utah, in the United States. The water of the Dead Sea has a greasy feel to it. The water stings cuts, and causes pain if it comes in contact with the eyes. One of the most unusual properties of the Dead Sea is its discharge of asphalt. From deep seeps, the Dead Sea constantly spits up small pebbles of the black substance. After earthquakes, chunks as large as houses may be produced. The Dead Sea area has become a major center for health research and treatment for several reasons. The mineral content of the waters, the very low content of pollens and other allergens in the atmosphere, the reduced ultraviolet component of solar radiation, and the higher atmospheric pressure at this great depth each have specific health effects. For example: persons suffering reduced respiratory function from diseases such as cystic fibrosis, seem to benefit from the increased atmospheric pressure. Sufferers of the skin disorder Psoriasis also benefit from the ability to sunbathe for long periods in the area due to its position below sea level and subsequent result that many of the sun's harmful UV rays are reduced. Flora and fauna The sea is called "dead" because its high salinity means no fish or macroscopic aquatic organisms can live in it, though minuscule quantities of bacteria and microbial fungi are present. In times of flood the salt content of the Dead Sea can drop from its usual 35% salinity to 30% or lower. In the wakes of rainy winters the Dead Sea temporarily comes to life. In 1980, after one such rainy winter, the normally dark blue Dead Sea turned red. Researchers from Hebrew University found the Dead Sea to be teeming with a type of algae called Dunaliella. The Dunaliella in turn nourished carotenoid-containing (red-pigmented) halobacteria whose presence is responsible for the color change. Since 1980 the Dead Sea basin has been dry and the algae and the bacteria have not returned in measurable numbers. Many animal species make their homes in the mountains surrounding the Dead Sea. A hiker can see camels, ibex, hares, hyraxes, jackals, foxes, and even leopards. Hundreds of bird species inhabit the zone as well. Both Jordan and Israel have established nature reserves around the Dead Sea. The delta of the Jordan river was formerly a veritable jungle of papyrus and palm trees. Flavius Josephus described Jericho as "the most fertile spot in Judea". In Roman and Byzantine times sugarcane, henna, and sycamore all made the lower Jordan valley quite wealthy. One of the most valuable products produced by Jericho was the sap of the balsam tree, which could be made into perfume. By the nineteenth century Jericho's fertility was a thing of the past. Human history The human history of the Dead Sea goes all the way back to remote antiquity. Just north of the Dead Sea is Jericho, the oldest continually occupied town in the world. Somewhere, perhaps on the Dead Sea's southeast shore, are the cities mentioned in the Book of Genesis which were destroyed in the times of Abraham: Sodom and Gomorra and the three other "Cities of the Plain". King David hid from Saul at Ein Gedi nearby. The Greeks knew the Dead Sea as "Lake Asphaltites", due to the naturally surfacing asphalt. Aristotle wrote about the remarkable waters. During the Egyptian conquest it is said that Queen Cleopatra obtained exclusive rights to build cosmetic and pharmaceutical factories in the area. Later, the Nabateans discovered the value of bitumen extracted from the Dead Sea needed by the Egyptians for embalming their mummies. Prominent personages linked with the Dead Sea and its surroundings are Herod the Great, Jesus of Nazareth, and John the Baptist. Also in Roman times some Essenes had settled on the Dead Sea's western shore; Pliny the Elder identifies their location with the words, "on the west side of the Dead Sea, away from the coast ... above the town of Engeda" (Natural History, Bk 5.73); and it is therefore a hugely popular though not uncontested hypothesis today, that same Essenes are identical with the settlers at Qumran and that "the Dead Sea Scrolls" discovered during the 20th century in the nearby caves had been their own library. King Herod the Great built/re-built several fortresses and palaces on the Western Bank of the Dead Sea. The most famous was Masada, where, in 66-70 AD, a small group of rebellious Jewish zealots held out against the might of the Roman Legion, and Machaerus where, it has been argued from the Gospel according to Luke 3:20, that John the Baptist had been imprisoned by Herod Antipas and met his death. The remoteness of the region attracted Greek Orthodox monks since the Byzantine era. Their monasteries such as Saint George in Wadi Kelt and Mar Saba in the Judean Desert are places of pilgrimage. In Islamic tradition, the Dead Sea was about the land in which the Prophet Lut (Lot in the Hebrew scriptures) lived. His tribe had done wrong and had therefore been given a punishment for such deeds. The punishment arrived when angels were sent down by Allah to Lut. The angels raised the land where the prophet's tribe lived and threw it back into the ground, causing the ground near the impact to cave in. Thus, the lowest land on Earth was formed because of this punishment. The sinners were destroyed and the followers were saved. Bedouin tribes have continuously lived in this area, and more recently explorers and scientists arrived to analyze the minerals and conduct research into the unique climate. Since the 1960s, tourists from all the over world have also explored the Dead Sea region. Potash and salt works In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. The Palestine Potash Company was chartered in 1929 (after its founder, Moses Novomeysky, a Jewish engineer from Siberia, worked for the charter for over ten years). The first plant was on the north shore of the Dead Sea at Kalia and produced potash, or potassium chloride, by solar evaporation of the brine. Employing Arabs and Jews, it was an island of peace in turbulent times. The company quickly grew into the largest industrial site in the Middle East and in 1934 built a second plant on the southwest shore, in the Sodom area, south of the 'Lashon' region of the Dead Sea. The Dead Sea Works Ltd. was established in 1952 as a state-owned company to extract potash and other minerals from the Dead Sea. From the Dead Sea brine, Israel produces (2001) 1.77 million tons potash, 206,000 tons elemental bromine, 44,900 tons caustic soda, 25,000 tons magnesium metal, and sodium chloride. On the Jordanian side of the Dead Sea, the Arab Potash Co. (APC), formed in 1956, produces 2.0 million tons of potash annually, as well as sodium chloride and bromine. Both companies use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea for the purpose of producing carnallite, potassium magnesium chloride, which is then processed further to produce potassium chloride. The power plant on the Israeli side allows production of magnesium metal (by a subsidiary, Dead Sea Magnesium Ltd.). The salt evaporation pans are visible from space. Saving the Dead Sea
The road to the Dead Sea The world's lowest road runs along the Israeli shores of the Dead Sea at 393 m (1,289 ft) below sea level. This road was also made famous in Naomi Shemer's song Jerusalem of Gold. Water attractions Besides the unique water of the Dead Sea itself, there are also health spas and hot springs along the shore. There is also the Israeli Atractziah Water Park (across from Kalia Kibbutz) and swimming pools in the large Hotel Resort. Miscellanea See also Further reading Notes | |||||||||||||||||||||||||||||||||||||||||||||||
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