در برخی منابع از آن با نام دریاچه نمک یاد شدهاست. سواحل اطراف آن پستترین نقطهٔ خشکیهای زمین است. این دریا برای این دریای مرده نامیده میشود که هیچ جانور یا گیاهی بهطور دائمی در آن زندگی نمیکند. آب آن هشت-نه برابر شورتر از آب اقیانوسهاست.
دریای مرده با کمآبی شدید مواجه است اما محو نخواهد شد. هرچه آب پایین میرود، غلظت و شوری دریاچه بیشتر میشود و نهایتاً به جایی میرسد که میزان تبخیر متوقف میشود؛ بنابراین دریای مرده احتمالاً به مراتب کوچکتر از این که هست میشود، اما بهکل محو نمیشود.
تنها رود اردن و بعضی قناتهای کوچک به این دریا منتهی میشوند. آب آن فقط از طریق تبخیر کاهش پیدا میکند، پس در نتیجه میزان نمک و سایر املاح که از طریق رود اردن و دیگر نهرهای کوچک به آن وارد میشود، افزایش مییابد.
این دریاچه با ۳۴٫۲٪ غلظت مواد محلول(در سال ۲۰۱۳)، شورترین دریاچهٔ دنیاست. بهطور کلی میزان نمک آبهای آزاد(اقیانوسها و دریاها) حدود ۳٫۵٪ است؛ بنابراین شوری آن بیش از ۹٫۵ برابر آبهای آزاد است.
به دلیل ارتفاع پایین این منطقه از سطح دریا، پساب کشاورزی و پساب ناشی از خاکشویی مناطق دورتر به صورت چشمههایی در کف این دریاچه به آن وارد میشود. پسابهای کشاورزی حاوی مقدار زیادی املاح معدنی هستند. تبخیر گسترده و ورود دائمی آب شور باعث بالا رفتن شدید غلظت آب و جرم حجمی آن شدهاست، به گونهای که انسان در این آب شناور میماند.
با آنکه از هر سه مولکول در آب این دریاچه تنها دو تایشان مولکول آباند، بر روی سنگهای اعماق این دریاچه بیوفیلمهای سبز و باکتریهای سولفیدخوار زندگی میکنند، و گاه که وضعیت آب مساعد باشد، رویش آغازیان باعث به رنگ سرخ درآمدن آب دریاچه میشود. در اثر وجود مقدار زیاد نمک و دیگر مواد سمی، موجودات زنده نمیتوانند در این دریا باقی بمانند. از این رو ماهی و دیگر جانوران آبزی رود اردن به محض ورود به این دریا میمیرند.
سرعت پایین رفتن سطح آب دریا هر سال حدود یک متر است. در دوران جنگ جهانی اول، چند مهندس بریتانیایی حرف نخست اسمشان را روی یک تخته سنگ که لب آب بود حک کردند که مشخص شود آب تا کجاست. درست صد سال پس از آن موقع، آن تخته سنگ حدود ۲ کیلومتر بالاتر از سطح آب است. افزایش شمار گودالهای ناشی از نشست زمین موجب شده امنیت کشاورزی منطقه به خطر بیفتد.
رویهم طی چهل سال، بیش از ۵۵۰۰ گودال پیرامون دریای مرده ایجاد شدهاست. گودالهای فرونشست زمین وقتی به وجود میآیند که رسوب نمکی در زیر زمین فرو میریزد، یا آب شیرینی که رسوب نمک را در زیر زمین میشوید و لایههای بالایی آن نشست میکنند. این گودالها گاه عظیمند – به قطر ۱۰۰ متر و عمق ۵۰ متر. گویی زمینلرزهای شدید طی دههها منطقه را تکان میدادهاست.
بر پایه بررسیهای علمی، دریای مرده در یک مرحله با محیط اطراف به تعادل خواهد رسید و دیگر کوچک نمیشود. یعنی میزان آبی که در ترکیب معجونگونه دریاچه است با میزان بخار آب موجود در هوای بالای دریاچه به تعادل میرسد. از این گذشته، دریای مرده خاصیت نمگیری دارد یعنی میتواند مولکولهای آب پیرامونش را جذب کند.
کاهش ورودی آب از رود اردن[ویرایش]
تنها منبع تأمینکننده آب بحرالمیت، رود اردن است. در حقیقت دلیل اصلی کاهش شدید سطح آب بحرالمیت، کاهش آب رود اردن است. رود اردن از یک سو وارد میشود اما از سوی دیگر بیرون نمیرود، همینجا میماند و بخار میشود. بعضی جاهای کرانه باختری رود (که در دست اسرائیل است) آب آنقدر کم شده که در فصل خشک به جوی آبی میماند. رود اردن از آبراههای مهم دنیای باستان بود. حتی در دوران مدرن هم رودی بزرگ بود که گاه در فصل بارندگی طغیان میکرد. در گذشته در جاهایی پهنای رود حدود ۳۰ متر بوده؛ برای مثال سال ۱۹۲۷ رود اردن هنوز آنقدر آب داشت که یک مهندس روس یهودی به نام پینچاس روتنبرگ کنار آن یک نیروگاه کوچک آبی بسازد. ساختمان نیروگاه هنوز برجاست، اما وسط صحرایی بیآبوعلف، نه کنار رود.
بدیهی است که جغرافیای منطقه طی این سالها تغییر نکرده. بخش شمالی رود به دریاچه جلیل (یا دریاچه طبریه) میریزد و بخش جنوبی از آن سرازیر شده به بحرالمیت میریزد. آنچه تغییر اساسی کرده آبی است که به این سیستم وارد و از آن خارج میشود. در حقیقت مسئله اصلی در دهههای گذشته سیاست آب کشورهای منطقه بوده. اسرائیل در بخش جنوبی دریاچه جلیل سد ساخته و عملاً مقدار آبی را که وارد اردن میشود، کنترل میکند. دریاچه جلیل – بهعنوان یک منبع آب – برای اسرائیلیها اهمیت راهبردی دارد، هرچند که این کشور در سالهای اخیر آب شیرینی را که از نمکزدایی آب مدیترانه تولید میکند آرامآرام افزایش دادهاست. دولت اسرائیل از دهه پنجاه میلادی – یعنی یک دهه پیش از ساخت سد – از منابع آب دره رود اردن برداشت میکرده که برای کشاورزان اردنی و فلسطینی (در کرانه باختری) مشکلساز بوده چون برای کشاورزی و سیر کردن شکمشان به این آب نیاز دارند. دولت اسرائیل هم البته مشکلی مشابه دارد – هرچند دستکم پول و فناوری لازم برای تأمین آب مردمش را دارد. مشکل اسرائیل این است که مهمترین منبع تأمین آب رود اردن، یعنی رود یرموک از سوریه میگذرد. از حدود سی سال پیش به این سو، سوریها بیش از چهل سد برای مهار آب یرموک ساختهاند – آبی که پیش از آن به رود اردن میریخت. بعضی اردنیها معتقدند سوریه بعضی از این سدها را برای تنبیه اسرائیل و اردن (به خاطر پیمان صلح ۱۹۹۴) ساخته. اما بعضی دیگر میپذیرند که سوریه هم مشکل آب داشته و این سدها را ساخته که ساکنانش بیآب نمانند. دلیل ساختن سدها هرچه باشد، واقعیت آن است که آبی که به رود اردن میریزد کم شده؛ اردن هم بنا به نیاز خودش سد ساختهاست. هرچند در سالهای اخیر اسرائیل اجازه داده آب بیشتری از دریاچه جلیل به رود اردن بریزد.
حوضچههای عظیم تبخیر[ویرایش]
هم اسرائیل هم اردن حوضچههای عظیم تبخیر دارند که در آن فسفاتهای گرانقیمت را از آب دریاچه استخراج میکنند و بهعنوان کود میفروشند. با این حال مهمترین علت بحران دریای مرده همان کم شدن شدید آب رود اردن است.
The Dead Sea (Hebrew: יָם הַמֶּלַח Yam ha-Melah lit. Sea of Salt; Arabic: البحر الميت Al-Bahr al-Mayyit) is a salt lake bordered by Jordan to the east and Israel and the West Bank to the west. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.
Its surface and shores are 430.5 metres (1,412 ft) below sea level, Earth's lowest elevation on land. It is 304 m (997 ft) deep, the deepest hypersaline lake in the world. With a salinity of 342 g/kg, or 34.2% (in 2011), it is one of the world's saltiest bodies of water – 9.6 times as salty as the ocean – and has a density of 1.24 kg/litre, which makes swimming similar to floating. This salinity makes for a harsh environment in which plants and animals cannot flourish, hence its name. The Dead Sea's main, northern basin is 50 kilometres (31 mi) long and 15 kilometres (9 mi) wide at its widest point.
The Dead Sea has attracted visitors from around the Mediterranean Basin for thousands of years. It was one of the world's first health resorts (for Herod the Great), and it has been the supplier of a wide variety of products, from asphalt for Egyptian mummification to potash for fertilisers.
The Dead Sea is receding at a swift rate; its surface area today is 605 km2 (234 sq mi), having been 1,050 km2 (410 sq mi) in 1930. The recession of the Dead Sea has begun causing problems, and multiple canals and pipelines proposals exist to reduce its recession. One of these proposals is the Red Sea–Dead Sea Water Conveyance project, carried out by Jordan, which will provide water to neighbouring countries, while the brine will be carried to the Dead Sea to help stabilise its water level. The first phase of the project is scheduled to begin in 2018 and be completed in 2021.
Etymology and toponymy
In Hebrew, the Dead Sea is Yām ha-Melaḥ (help·info) (ים המלח), meaning "sea of salt" (Genesis 14:3). The Bible uses this term alongside two others: the Sea of the Arabah (Yām ha-‘Ărāvâ ים הערבה), and the Eastern Sea (Yām ha-Mizraḥî ים המזרחי). The designation "Dead Sea" never appears in the Bible.
In prose sometimes the term Yām ha-Māvet (ים המוות, "sea of death") is used, due to the scarcity of aquatic life there. In Arabic the Dead Sea is called al-Bahr al-Mayyit (help·info) ("the Dead Sea"), or less commonly baḥrᵘ lūṭᵃ (بحر لوط, "the Sea of Lot"). Another historic name in Arabic was the "Sea of Zoʼar", after a nearby town in biblical times. The Greeks called it Lake Asphaltites (Attic Greek ἡ Θάλαττα ἀσφαλτῖτης, hē Thálatta asphaltĩtēs, "the Asphaltite sea").
The Dead Sea is an endorheic lake located in the Jordan Rift Valley, a geographic feature formed by the Dead Sea Transform (DST). This left lateral-moving transform fault lies along the tectonic plate boundary between the African Plate and the Arabian Plate. It runs between the East Anatolian Fault zone in Turkey and the northern end of the Red Sea Rift offshore of the southern tip of Sinai. It is here that the Upper Jordan River/Sea of Galilee/Lower Jordan River water system comes to an end.
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, forming pools and quicksand pits along the edges. There are no outlet streams.
The Mujib River, biblical Arnon, is one of the larger water sources of the Dead Sea other than the Jordan. The Wadi Mujib valley, 420 m below the sea level in the southern part of the Jordan valley, is a biosphere reserve, with an area of 212 km2 (82 sq mi). Other more substantial sources are Wadi Darajeh (Arabic)/Nahal Dragot (Hebrew), and Nahal Arugot. Wadi Hasa (biblical Zered) is another wadi flowing into the Dead Sea.
Rainfall is scarcely 100 mm (4 in) per year in the northern part of the Dead Sea and barely 50 mm (2 in) in the southern part. The Dead Sea zone's aridity is due to the rainshadow effect of the Judaean Mountains. The highlands east of the Dead Sea receive more rainfall than the Dead Sea itself.
To the west of the Dead Sea, the Judaean mountains rise less steeply and are much lower than the mountains to the east. Along the southwestern side of the lake is a 210 m (700 ft) tall Halite (mineral) formation called "Mount Sodom".
There are two contending hypotheses about the origin of the low elevation of the Dead Sea. The older hypothesis is that the Dead Sea lies in a true rift zone, an extension of the Red Sea Rift, or even of the Great Rift Valley of eastern Africa. A more recent hypothesis is that the Dead Sea basin is a consequence of a "step-over" discontinuity along the Dead Sea Transform, creating an extension of the crust with consequent subsidence.
During the late Pliocene-early Pleistocene, around 3.7 million years ago, what is now the valley of the Jordan River, Dead Sea, and the northern Wadi Arabah was repeatedly inundated by waters from the Mediterranean Sea. The waters formed in a narrow, crooked bay that is called by geologists the Sedom Lagoon, which was connected to the sea through what is now the Jezreel Valley. The floods of the valley came and went depending on long-scale changes in the tectonic and climatic conditions.
The Sedom Lagoon extended at its maximum from the Sea of Galilee in the north to somewhere around 50 km (30 mi) south of the current southern end of the Dead Sea, and the subsequent lakes never surpassed this expanse. The Hula Depression was never part of any of these water bodies due to its higher elevation and the high threshold of the Korazim block separating it from the Sea of Galilee basin.
Approximately two million years ago, the land between the Rift Valley and the Mediterranean Sea rose to such an extent that the ocean could no longer flood the area. Thus, the long lagoon became a landlocked lake.
The first prehistoric lake to follow the Sedom Lagoon is named Lake Amora (which possibly appeared in the early Pleistocene; its sediments developed into the Amora (Samra) Formation, dated to over 200-80 kyr BP), followed by Lake Lisan (c. 70-14 kyr) and finally by the Dead Sea.
The water levels and salinity of the successive lakes (Amora, Lisan, Dead Sea) have either risen or fallen as an effect of the tectonic dropping of the valley bottom, and due to climate variation. As the climate became more arid, Lake Lisan finally shrank and became saltier, leaving the Dead Sea as its last remainder.
From 70,000 to 12,000 years ago, Lake Lisan's level was 100 m (330 ft) to 250 m (820 ft) higher than its current level. Its level fluctuated dramatically, rising to its highest level around 26,000 years ago, indicating a very wet climate in the Near East. Around 10,000 years ago, the lake's level dropped dramatically, probably even lower than today. During the last several thousand years, the lake has fluctuated approximately 400 m (1,300 ft), with some significant drops and rises. Current theories as to the cause of this dramatic drop in levels rule out volcanic activity; therefore, it may have been a seismic event.
Salt mounts formation
In prehistoric times[dubious ], great amounts of sediment collected on the floor of Lake Amora. The sediment was heavier than the salt deposits and squeezed the salt deposits upwards into what are now the Lisan Peninsula and Mount Sodom (on the southwest side of the lake). Geologists explain the effect in terms of a bucket of mud into which a large flat stone is placed, forcing the mud to creep up the sides of the bucket. When the floor of the Dead Sea dropped further due to tectonic forces, the salt mounts of Lisan and Mount Sodom stayed in place as high cliffs (see salt dome).
The Dead Sea's climate (BWh) offers year-round sunny skies and dry air. It has less than 50 millimetres (2 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 region has weaker ultraviolet radiation, particularly the UVB (erythrogenic rays). Given the higher atmospheric pressure, the air has a slightly higher oxygen content (3.3% in summer to 4.8% in winter) as compared to oxygen concentration at sea level. Barometric pressures at the Dead Sea were measured between 1061 and 1065 hPa and clinically compared with health effects at higher altitude. (This barometric measure is about 5% higher than sea level standard atmospheric pressure of 1013.25 hPa, which is the global ocean mean or ATM.) The Dead Sea affects temperatures nearby because of the moderating effect a large body of water has on climate. During the winter, sea temperatures tend to be higher than land temperatures, and vice versa during the summer months. This is the result of the water's mass and specific heat capacity. On average, there are 192 days above 30 °C (86 °F) annually.
With 34.2% salinity (in 2011), it is one of the world's saltiest bodies of water, though Lake Vanda in Antarctica (35%), Lake Assal in Djibouti (34.8%), Lagoon Garabogazköl in the Caspian Sea (up to 35%) and some hypersaline ponds and lakes of the McMurdo Dry Valleys in Antarctica (such as Don Juan Pond (44%)) have reported higher salinities.
Until the winter of 1978–79, when a major mixing event took place, the Dead Sea was composed of two stratified layers of water that differed in temperature, density, age, and salinity. The topmost 35 meters (115 ft) or so of the Dead Sea had an average salinity of 342 parts per thousand (in 2002), and a temperature that swung between 19 °C (66 °F) and 37 °C (99 °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 was saltier than the lower layer. Nevertheless, the upper layer remained suspended above the lower layer because its waters were warmer and thus less dense. When the upper layer cooled so its density was greater than the lower layer, the waters mixed (1978–79). 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 very different from that of ocean water. The exact composition of the Dead Sea water varies mainly with season, depth and temperature. In the early 1980s, the concentration of ionic species (in g/kg) of Dead Sea surface water was Cl− (181.4), Br− (4.2), SO42− (0.4), HCO3− (0.2), Ca2+ (14.1), Na+ (32.5), K+ (6.2) and Mg2+ (35.2). The total salinity was 276 g/kg. These results show that the composition of the salt, as anhydrous chlorides on a weight percentage basis, was calcium chloride (CaCl2) 14.4%, potassium chloride (KCl) 4.4%, magnesium chloride (MgCl2) 50.8% and sodium chloride (NaCl) 30.4%. In comparison, the salt in the water of most oceans and seas is approximately 85% sodium chloride. The concentration of sulfate ions (SO42−) is very low, and the concentration of bromide ions (Br−) is the highest of all waters on Earth.
The salt concentration of the Dead Sea fluctuates around 31.5%. This is unusually high and results in a nominal density of 1.24 kg/l. Anyone 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.
An unusual feature of the Dead Sea is its discharge of asphalt. From deep seeps, the Dead Sea constantly spits up small pebbles and blocks of the black substance. Asphalt-coated figurines and bitumen-coated Neolithic skulls from archaeological sites have been found. Egyptian mummification processes used asphalt imported from the Dead Sea region.
The Dead Sea area has become a location for health research and potential treatment for several reasons. The mineral content of the water, the 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 may have specific health effects. For example, persons experiencing reduced respiratory function from diseases such as cystic fibrosis seem to benefit from the increased atmospheric pressure.
The region's climate and low elevation have made it a popular center for assessment of putative therapies:
Climatotherapy at the Dead Sea may be a therapy for psoriasis by sunbathing for long periods in the area due to its position below sea level and subsequent result that UV rays are partially blocked by the increased cloud cover over the Dead Sea.
Dead Sea mud pack therapy has been suggested to temporarily relieve pain in patients with osteoarthritis of the knees. According to researchers of the Ben Gurion University of the Negev, treatment with mineral-rich mud compresses can be used to augment conventional medical therapy.
Fauna and flora
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% to 30% 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. Researchers from Hebrew University of Jerusalem found the Dead Sea to be teeming with a type of alga called Dunaliella. Dunaliella in turn nourished carotenoid-containing (red-pigmented) halobacteria, whose presence caused the color change. Since 1980, the Dead Sea basin has been dry and the algae and the bacteria have not returned in measurable numbers.
In 2011 a group of scientists from Be'er Sheva, Israel and Germany discovered fissures in the floor of the Dead Sea by scuba diving and observing the surface. These fissures allow fresh and brackish water to enter the Dead Sea. They sampled biofilms surrounding the fissures and discovered numerous species of bacteria and archaea.
Many animal species live in the mountains surrounding the Dead Sea. Hikers can see 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 jungle of papyrus and palm trees. The Jewish historian Flavius Josephus described Jericho as "the most fertile spot in Judea". In Roman and Byzantine times, sugarcane,[dubious ] henna, and sycamore fig all made the lower Jordan valley 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 19th century, Jericho's fertility had disappeared.[dubious ]
There are several small communities near the Dead Sea. These include Ein Gedi, Neve Zohar and the Israeli settlements in the Megilot Regional Council: Kalya, Mitzpe Shalem and Avnat. There is a nature preserve at Ein Gedi, and several Dead Sea hotels are located on the southwest end at Ein Bokek near Neve Zohar. Highway 90 runs north-south on the Israeli side for a total distance of 565 km (351 mi) from Metula on the Lebanese border in the north to its southern terminus at the Egyptian border near the Red Sea port of Eilat.
Potash City is a small community on the Jordanian side of the Dead Sea, and others including Suweima. Highway 65 runs north-south on the Jordanian side from near Jordan's northern tip down past the Dead Sea to the port of Aqaba.
Just northwest of the Dead Sea is Jericho. Somewhere, perhaps on the southeastern shore, would be the cities mentioned in the Book of Genesis which were said to have been destroyed in the time of Abraham: Sodom and Gomorra (Genesis 18) and the three other "Cities of the Plain", Admah, Zeboim and Zoar (Deuteronomy 29:23). Zoar escaped destruction when Abraham's nephew Lot escaped to Zoar from Sodom (Genesis 19:21–22). Before the destruction, the Dead Sea was a valley full of natural tar pits, which was called the vale of Siddim. King David was said to have hidden from Saul at Ein Gedi nearby.
In Ezekiel 47:8–9 there is a specific prophecy that the sea will "be healed and made fresh", becoming a normal lake capable of supporting marine life. A similar prophecy is stated in Zechariah 14:8, which says that "living waters will go out from Jerusalem, half of them to the eastern sea [likely the Dead Sea] and half to the western sea [the Mediterranean]."
Greek and Roman period
Aristotle wrote about the remarkable waters. The Nabateans and others discovered the value of the globs of natural asphalt that constantly floated to the surface where they could be harvested with nets. The Egyptians were steady customers, as they used asphalt in the embalming process that created mummies. The Ancient Romans knew the Dead Sea as "Palus Asphaltites" (Asphalt Lake).
The Dead Sea was an important trade route with ships carrying salt, asphalt and agricultural produce. Multiple anchorages existed on both sides of the sea, including in Ein Gedi, Khirbet Mazin (where the ruins of a Hasmonean-era dry dock are located), Numeira and near Masada.
King Herod the Great built or rebuilt several fortresses and palaces on the western bank of the Dead Sea. The most famous was Masada, where in 70 CE a small group of Jewish zealots fled after the fall of the destruction of the Second Temple. The zealots survived until 73 CE, when a siege by the X Legion ended in the deaths by suicide of its 960 inhabitants. Another historically important fortress was Machaerus (מכוור), on the eastern bank, where, according to Josephus, John the Baptist was imprisoned by Herod Antipas and died.
Also in Roman times, some Essenes 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 but contested 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.
Various sects of Jews settled in caves overlooking the Dead Sea. The best known of these are the Essenes of Qumran, who left an extensive library known as the Dead Sea Scrolls. The town of Ein Gedi, mentioned many times in the Mishna, produced persimmon for the temple's fragrance and for export, using a secret recipe. "Sodomite salt" was an essential mineral for the temple's holy incense, but was said to be dangerous for home use and could cause blindness. The Roman camps surrounding Masada were built by Jewish slaves receiving water from the towns around the lake. These towns had drinking water from the Ein Feshcha springs and other sweetwater springs in the vicinity.
Intimately connected with the Judean wilderness to its northwest and west, the Dead Sea was a place of escape and refuge. 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 Judaean Desert, are places of pilgrimage.
In the 19th century the River Jordan and the Dead Sea were explored by boat primarily by Christopher Costigan in 1835, Thomas Howard Molyneux in 1847, William Francis Lynch in 1848, and John MacGregor in 1869. The full text of W. F. Lynch's 1949 book Narrative of the United States' Expedition to the River Jordan and the Dead Sea is available online. Charles Leonard Irby and James Mangles travelled along the shores of the Dead Sea already in 1817–18, but didn't navigate on its waters.
Explorers and scientists arrived in the area to analyze the minerals and research the unique climate.
After the find of the "Moabite Stone" in 1868 on the plateau east of the Dead Sea, Moses Wilhelm Shapira and his partner Salim al-Khouri forged and sold a whole range of presumed "Moabite" antiquities, and in 1883 Shapira presented what is now known as the "Shapira Strips", a supposedly ancient scroll written on leather strips which he claimed had been found near the Dead Sea. The strips were declared to be forgeries and Shapira took his own life in disgrace.
In the late 1940s and early 1950s, hundreds of religious documents dated between 150 BCE and 70 CE were found in caves near the ancient settlement of Qumran, about one mile (1.6 kilometres) inland from the northwestern shore of the Dead Sea (presently in the West Bank). They became known and famous as the Dead Sea Scrolls.
Tourism and leisure
British Mandate period
Israel has 15 hotels along the Dead Sea shore, generating total revenues of $291 million in 2012. Most Israeli hotels and resorts on the Dead Sea are on a six-kilometre (3.7-mile) stretch of the southern shore.
On the Jordanian side, nine international franchises have opened seaside resort hotels near the King Hussein Bin Talal Convention Center, along with resort apartments, on the eastern shore of the Dead Sea. The 9 hotels have boosted the Jordanian side's capacity to 2,800 rooms.
The Palestinian Dead Sea Coast is about 40 kilometres (25 miles) long. The World Bank estimates that a Palestinian Dead Sea tourism industry could generate $290 million of revenues per year and 2,900 jobs. However, Palestinians have been unable to obtain construction permits for tourism-related investments on the Dead Sea. According to the World Bank, Officials in the Palestinian Ministry of Tourism and Antiquities state that the only way to apply for such permits is through the Joint Committees established under the Oslo Agreement, but the relevant committee has not met with any degree of regularity since 2000.
British Mandate period
In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced the sea was a natural deposit of potash (potassium chloride) and bromine. The Palestine Potash Company was chartered in 1929, after its founder, Siberian Jewish engineer and pioneer of Lake Baikal exploitation, Moses Novomeysky, worked for the charter for over ten years having first visited the area in 1911. The first plant, on the north shore of the Dead Sea at Kalya, commenced production in 1931 and produced potash 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 Mount Sodom area, south of the 'Lashon' region of the Dead Sea. Palestine Potash Company supplied half of Britain's potash during World War II. Both plants were destroyed by the Jordanians in the 1948 Arab–Israeli War.
The Dead Sea Works was founded in 1952 as a state-owned enterprise based on the remnants of the Palestine Potash Company. In 1995, the company was privatized and it is now owned by Israel Chemicals. 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. Israeli companies generate around US$3 billion annually from the sale of Dead Sea minerals (primarily potash and bromine), and from other products that are derived from Dead Sea Minerals.
On the Jordanian side of the Dead Sea, Arab Potash (APC), formed in 1956, produces 2.0 million tons of potash annually, as well as sodium chloride and bromine. The plant is located at Safi, South Aghwar Department, in the Karak Governorate.
Jordanian Dead Sea mineral industries generate about $1.2 billion in sales (equivalent to 4 percent of Jordan's GDP).
The Palestinian Dead Sea Coast is about 40 kilometres (25 miles) long. The Palestinian economy is unable to benefit from Dead Sea chemicals due to restricted access, permit issues and the uncertainties of the investment climate. The World Bank estimates that a Palestinian Dead Sea chemicals industry could generate $918M incremental value added per year, "almost equivalent to the contribution of the entire manufacturing sector of Palestinian territories today".
Both companies, Dead Sea Works Ltd. and Arab Potash, 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 ponds are separated by a central dike that runs roughly north-south along the international border. The power plant on the Israeli side allows production of magnesium metal (by a subsidiary, Dead Sea Magnesium Ltd.).
Due to the popularity of the sea's therapeutic and healing properties, several companies have also shown interest in the manufacturing and supplying of Dead Sea salts as raw materials for body and skin care products.
Recession and environmental concerns
Since 1930, when its surface was 1,050 km2 (410 sq mi) and its level was 390 m (1,280 ft) below sea level, the Dead Sea has been monitored continuously. In recent decades,[which?] the Dead Sea has been rapidly shrinking because of diversion of incoming water from the Jordan River to the north. The southern end is fed by a canal maintained by the Dead Sea Works, a company that converts the sea's raw materials. From a water surface of 395 m (1,296 ft) below sea level in 1970 it fell 22 m (72 ft) to 418 m (1,371 ft) below sea level in 2006, reaching a drop rate of 1 m (3 ft) per year. As the water level decreases, the characteristics of the Sea and surrounding region may substantially change.
The Dead Sea level drop has been followed by a groundwater level drop, causing brines that used to occupy underground layers near the shoreline to be flushed out by freshwater. This is believed to be the cause of the recent appearance of large sinkholes along the western shore—incoming freshwater dissolves salt layers, rapidly creating subsurface cavities that subsequently collapse to form these sinkholes.
In May 2009 at the World Economic Forum, Jordan announced its plans to construct the "Jordan National Red Sea Development Project" (JRSP). This is a plan to convey seawater from the Red Sea near Aqaba to the Dead Sea. Water would be desalinated along the route to provide fresh water to Jordan, with the brine discharge sent to the Dead Sea for replenishment. Israel has expressed its support and will likely benefit from some of the water delivery to its Negev region.
At a regional conference in July 2009, officials expressed concern about the declining water levels. Some suggested industrial activities around the Dead Sea might need to be reduced. Others advised environmental measures to restore conditions such as increasing the volume of flow from the Jordan River to replenish the Dead Sea. Currently, only sewage and effluent from fish ponds run in the river's channel. Experts also stressed the need for strict conservation efforts. They said agriculture should not be expanded, sustainable support capabilities should be incorporated into the area and pollution sources should be reduced.
In October 2009, the Jordanians announced accelerated plans to extract around 300 million cubic metres (11 billion cubic feet) of water per year from the Red Sea, desalinate it for use as fresh water and send the waste water to the Dead Sea by tunnel, despite concerns about inadequate time to assess the potential environmental impact. According to Jordan's minister for water, General Maysoun Zu'bi, this project could be considered as the first phase of the Red Sea–Dead Sea Water Conveyance.
In December 2013, Israel, Jordan and the Palestinian Authority signed an agreement for laying a water pipeline to link the Red Sea with the Dead Sea. The pipeline will be 180 km (110 mi) long and is estimated to take up to five years to complete. In January 2015 it was reported that the level of water is now dropping by 1 m (3 ft) a year.
On 27 November 2016, it was announced that the Jordanian government is shortlisting five consortiums to implement the project. Jordan's ministry of Water and Irrigation said that the $100 million first phase of the project will begin construction in the first quarter of 2018, and will be completed by 2021.