The Dead Sea holds a few world records of which one is being the lowest point on Earth. As for the degree of salinity, it is located among the four saltiest bodies of water in the world. Those special conditions are an outcome of its extreme geo-morphological structure, alongside a harsh desert climate. These create an environment of constant dramatic changes forming a breathtaking landscape, unique and different from any other in the world.
The Dead Sea is actually a huge lake, located in the heart of the Turkish-African Great Rift between Jordan and Israel. Its length is about 50 kilometers and the average width is 15 kilometers. It was formerly divided into two basins, with the North and South separated by the Lisan (Arabic for ‘Tongue’) peninsula. Since the late ’70s, the surface severely dropped and the Southern basin has dried out. The sea is presently confined to the Northern basin. The surface elevation is now 437m below sea level, and its depth is around 380m. The high salinity of around 34% allows no life in the water, although several scientists recently discovered microorganisms that do survive the outstanding osmotic pressures. The sea is an abundant resource of various precious minerals and millions of tons of potassium, magnesium, and bromide are manufactured annually to be marketed around the world.
The great rift
Continent shields are in constant motion. Mighty forces push some apart, pressing others against each other. The Dead Sea valley is a fraction of The Great Rift: a fault of some 37,000 miles that was created around 25 million years ago, as an outcome of an asymmetric shift between the Asian and the African shields. The Asian shield is shifting northbound about 1cm a year. The rapid movement forces frequent earthquakes along the rift. The fault’s axis’ angles produce an altering opening of ‘holes’ between the two shields. Among those are the “Akaba bay”, the “Dead Sea”, the “Sea of Galilee”, and the “Hula Valley”. Here, around the Dead Sea area, enormous rock layers sank into the magma. Alongside the horizontal shift, there’s also a vertical rise. Thus, the lowest exposed place on Earth is 437m below sea level and lays next to huge cliffs that tower to an elevation of 1750m.
Early stages of the sea
The deep and steep Rift was filled with water some 3 million years ago, as a result of massive floods caused by the rise of the Mediterranean Sea level. A 320 km-long basin covered the rift from the “Hula Valley” until almost 80 miles south to where the Dead Sea is today.
An elevation of a new anticline at the heart of the “Jessereel Valley” blocked this channel around 2 million years ago, and formed a prolonged lake of 320 km. Its isolation and limited rains led to a constant drop in the surface. Sedimentation of various minerals pushed the salt up, gradually raising its salinity. While the water was constantly evaporating, all salt remained locked in the basin. The percentage of salt has exceeded the bearing ability of the water, and tons of salt crystallized into large masses have sunk to the bottom, creating miles-high layers of salt beneath the sea. 60,000 years ago, the Dead Sea finally reached its contemporary shape. The deep and narrow form exposed it to significant fluctuations of level. Around 25,000 years ago, due to dramatic rainy millennia, the level rose to more than 100m above the contemporary one. Around 8,000 BC, the level was more or less stabilized to the one we know today.
Climate
The Dead Sea is located in the middle of the Judean desert. During the summer the temperature rises to over 40ºc and may remain above 20ºc (daytime) throughout the winter. The air is constantly dry, and the average precipitation is less than 2 inches a year. The massive evaporation does not affect the immediate surroundings but creates a visible constant mist hovering some 300m above the surface. On top of the other medical virtues of the Dead Sea, the high barometric pressure and the mist are perfect filters of UV radiation, attracting tourists from the whole world to sunbathe safely as an effective treatment of several skin diseases.
Rain-shed Desert
One of the unique attributes of the Dead Sea shores is them being a part of a ‘Rain-shed Desert’ – a unique phenomenon. Desert conditions reach some 130 kilometers north to the global latitude of the desert stripe, only a few miles east of the green, relatively rich in precipitation area around the Judean Mountains. The latter are drained towards the Mediterranean westbound, but the underground water stream towards the Dead Sea, forming long stripes of fresh water springs which allow many oases to develop in the midst of the harsh desert – a belt of thriving life brimming near the Dead Sea.
Water resources
The 20th century has brought an overwhelming growth of population to the Middle East alongside modern technologies. These allowed the locals to utterly seize the water resources, which until the modern era kept on feeding the Dead Sea, stabilizing its surface level. The main source was of course the River Jordan which solely supplied a billion cubic meters a year. An additional contribution was the numerous rivers that flow directly to the sea, especially from the East. But these were brutally cut off starting from the mid-’60s.
Two dams block all the outgoing fresh water from the Sea of Galilee, designated from 1965 for national Israeli consumption. The water of the “Yarmuch”, merging into the Jordan from the Jordanian-Syrian border was channeled in the same year to the Eastern side of the Jordan Valley. The rest of the rivers were gradually captured, today allowing the flow only of water from sulfur springs and waste water that sum up to less than 5% of the original flow, assisted by rare flash-flood water, and local drizzle, altogether a trifle donation, in comparison to the massive evaporation. All these led to a gradual receding of 10-20 inches per year.
The Dead Sea Works Company had introduced the sea to a fierce reality since the end of the 1970s. Formerly, the Southern shallow basin was used for deliberate evaporation of the water as the primal process in the production of the precious minerals. Since the surface dropped to cut off the two basins from each other, the Dead Sea Works started to pump water from the Northern basin and completely dried the southern one. The excessive exploitation of the sea causes a horrific drop of a meter every year, an interference that shutters the ecosystem and brings about severe outcomes.
Dead Sea Sinkholes
The combination of the drop in sea level alongside the prodigious flow of spring-water near the shores creates some interesting phenomena. The rocks circling the Dead Sea are mainly sedimentation of the previous phases of it and contain mainly aragonite, gypsum, and of course, remarkable amounts of salt. Some of the salt is set in huge underground boulders. As long as the surface is kept high, the condensed brine that intrudes the quick rock stabilizes the underground salt crystals. With the drop of the surface, the underground level drops as well, leaving the underground salt crystals exposed to fresh water. After several rainy seasons and the assistance of the constant flowing springs, the underground salt-boulders dissolve, leaving underground cavities named which tend to collapse occasionally in various spots around the Dead Sea.
The first incident occurred in 1981. A bus was parked awaiting hikers near Ein Bokek when a 25m sinkhole had opened abruptly under one of its wheels. A few other cases involving the injuries of several victims. A comprehensive survey held in the late 1990s led to the closing down of the Bungalow Resort, the Navy base, and a palm plantation near Ein Gedi, and basically required canceling of all progress plans around the sea. Today, the phenomenon is highly surveilled and under control. Beneath several roads, wooden fortification constructions were set, and huge ramps were built next to holiday resorts, all done to assure the welfare and safety of the visitors.
