THE DEAD SEA
DR. S.M. ALAM
Jan 31 - Feb 6, 2011
The Dead Sea also called the Salt Sea is a salt lake bordering Jordan to the east and Israel and the West Bank to the west. Its surface and shores are 422 meters (1,385 ft) below sea level, the lowest elevation on the Earth's surface on dry land.
The Dead Sea is 378 meters (1,240 ft) deep, the deepest hyper saline lake in the world. It is also one of the world's saltiest bodies of water, with 34.7 per cent salinity, though Lake Assal (Djibouti), Garabogazkˆl and some hyper saline lakes of the McMurdo Dry Valleys in Antarctica (such as Don Juan Pond) have reported higher salinities. It is 10 times more salty than all the oceans of the world.
This salinity makes for a harsh environment where animals cannot flourish, hence its name. The Dead Sea is 67 kilometers (42 miles) long and 18 kilometers (11 miles) wide at its widest point. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.
The sea has a density of 1.24 kg/L, making swimming difficult but providing a relaxing floating experience for tourists. The Jordan River is the only major water source flowing into the Dead Sea, although there are small perennial springs under and around the Dead Sea, creating pools and quicksand pits along the edges.
Rainfall is scarcely 100 mm per year in the northern part of the Dead Sea and barely 50 mm in the southern part. The Dead Sea's climate offers year round sunny skies and dry air. It has less than 100 millimeters (3.94 in) mean annual rainfall and a summer average temperature between 32 and 39 ∞C (90 and 102∞F). Winter average temperatures range between 20 and 23 ∞C (68 and 73∞F).
The mineral content of the Dead Sea is very different from that of ocean water. The exact composition of the Dead Sea water varies mainly with season, depth and temperature.
The salt in the water of most oceans and seas is approximately 97 per cent sodium chloride. The concentration of sulfate ions is very low, and the concentration of bromide ions is the highest of all waters on Earth. The sea itself is abundant in minerals acclaimed to have therapeutic value.
The salt concentration of the Dead Sea fluctuates around 31.5 per cent. This is unusually high and results in a nominal density of 1.24 kg/l. Any one can easily float in the Dead Sea because of natural buoyancy. In this respect, the Dead Sea is similar to the Great Salt Lake in Utah in the United States.
The Dead Sea area has become a major center for health research and treatment for several reasons. The mineral content of the water, 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.
The sea is called "dead" because its high salinity prevents macroscopic aquatic organisms, such as fish and aquatic plants, from living 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 per cent salinity to 30 per cent or lower.
The Dead Sea temporarily comes to life in the wake of rainy winters. In 1980, after one such rainy winter, the normally dark blue Dead Sea turned red.
Many animal species live in the mountains surrounding the Dead Sea. Hikers 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 fig 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. However, by the 19th century, Jericho's fertility had disappeared.
According to the tradition of Islam, the Dead Sea was near the land in which the Prophet Lut lived. The people in this area were considered wicked for their acts of homosexuality, robbery, and murder, and therefore Allah had ordained punishment to the people of Lut for these deeds. The punishment arrived when Allah sent down the angels in the form of handsome men as guests for Lut to host. When Lut's people heard of the men, they rushed to Lut's house and said that those men were very handsome and they wanted to take them. This was the final test for the people of Lut in which they failed, so the angel Jibrail raised the land, where the prophet's people lived, tipped it upside down, and threw it back on earth, causing the ground near the impact to cave in. The Holy Quran explained this situation in different: So when Our Commandment came, We turned (the towns of Sodom in Palestine) upside down and rained down on them stones of baked clay in a well-arranged manner, one after another, (Surah Al-Araf-7, verse-84; Suah Hud-11, verse-82; Surah Al-Hijr-15,verse-74; Surah Ash-Shuara-26, verse-173; Surah An-Naml-27,verse-58; Al-Ankabut-29, verse-29; and Surah As-Saffat-37, verse-136).
From the Dead Sea brine, the Israel produces 1.77 million tons potash, 206,000 tons elemental bromine, 44,900 tons caustic soda, 25,000 tons magnesium metal, and sodium chloride.
The surface of the Dead Sea is over 1,300 feet below sea level. The very bottom of the sea, in the deepest part, is over 2,300 feet below sea level. The Dead Sea is completely landlocked and it gets saltier with increasing depth. The surface, fed by the River Jordan, is the least saline. Down to about 130 feet (40 meters), the seawater comprises about 300 grams of salt per kilogram of seawater. That's about ten times the salinity of the oceans. Below 300 feet, though, the sea has 332 grams of salt per kilogram of seawater and is saturated. Salt precipitates out and piles up on the bottom of the sea.
There are no fish or any kind of swimming, squirming creatures living in or near the water. There are, however, several types of bacteria and one type of algae that have adapted to harsh life in the waters of the Dead Sea. What you'll see on the shores of the Sea is white, crystals of salt covering everything. And, this is no ordinary table salt, either. The water in the Dead Sea is deadly to most living things.
The Dead Sea is continually fed water from the rivers and streams coming down off the mountains that surround it. The only way water gets out of the Sea is through evaporation. This part of the world gets very hot. When the water evaporates, it leaves behind all the dissolved minerals in the Sea, just making it saltier. In fact, it's through the dual action of; 1) continuing evaporation and 2) minerals salts carried into the Sea from the local rivers, that makes the Sea so salty. The fact that the water doesn't escape the Sea just traps the salts within its shores.