Dead Sea
A view from the Israeli side looking across to Jordan
Coordinates	31°20′N 35°30′E / 31.333°N 35.5°E / 31.333; 35.5Coordinates: 31°20′N 35°30′E / 31.333°N 35.5°E / 31.333; 35.5
Lake type	Endorheic Hypersaline
Primary inflows	Jordan River
Primary outflows	None
Catchment area	41,650 km2 (16,080 sq mi)
Basin countries	Jordan Israel West Bank
Max. length	67.4 km (41.9 mi)
Max. width	18 km (11 mi)
Surface area	810 km2 (310 sq mi) North Basin
Average depth	118 m (387 ft)[1]
Max. depth	377 m (1,237 ft)
Water volume	147 km3 (35 cu mi)
Shore length1	135 km (84 mi)
Surface elevation	−423 m (−1,388 ft)[2]
References	[1][2]
1 Shore length is not a well-defined measure.

The Dead Sea (Arabic: البحر الميت‎  al-Baḥr al-Mayyit (help·info),^[3] Hebrew: יָם הַ‏‏מֶּ‏‏לַ‏ח‎‎, Yām HamMélaḥ, "Sea of Salt", also Hebrew: יָם הַ‏‏מָּוֶת‎‎, Yām HamMā́weṯ, "The Sea of Death"), 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 423 metres (1,388 ft) below sea level,^[2] Earth's lowest elevation on land. The Dead Sea is 377 m (1,237 ft) deep, the deepest hypersaline lake in the world. With 33.7% salinity, it is also one of the world's saltiest bodies of water, though Lake Assal (Djibouti), Garabogazköl and some hypersaline lakes of the McMurdo Dry Valleys in Antarctica (such as Don Juan Pond) have reported higher salinities. It is 8.6 times saltier than the ocean.^[4] This salinity makes for a harsh environment in which animals cannot flourish, hence its name. The Dead Sea is 67 kilometres (42 mi) long and 18 kilometres (11 mi) wide at its widest point. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.

The Dead Sea has attracted visitors from around the Mediterranean basin for thousands of years. Biblically, 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 a wide variety of products, from balms for Egyptian mummification to potash for fertilizers. People also use the salt and the minerals from the Dead Sea to create cosmetics and herbal sachets. In 2009, 1.2 million foreign tourists visited on the Israeli side.^{[citation needed]}

The sea has a density of 1.24 kg/L,^{[citation needed]} which makes swimming similar to floating.^[5]

Etymology and toponymy[link]

In Hebrew, the Dead Sea is  Yām ha-Melaḥ (help·info), meaning "sea of salt" (Genesis 14:3). In prose sometimes the term Yām ha-Māvet (ים המוות, "sea of death") is used, due to the scarcity of aquatic life there.^[6] In Arabic the Dead Sea is called  al-Bahr al-Mayyit (help·info)^[3] ("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^[7] sea"). The Bible also refers to it as Yām ha-Mizraḥî (ים המזרחי, "the Eastern sea") and Yām ha-‘Ărāvâ (ים הערבה, "Sea of the Arabah").

Geography[link]

Satellite photograph showing the location of the Dead 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.

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.^[8] There are no outlet streams.

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 Judean Hills. The highlands east of the Dead Sea receive more rainfall than the Dead Sea itself.

To the west of the Dead Sea, the Judean Hills 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 formation called "Mount Sodom".

Natural history[link]

There are two contending hypotheses about the origin of the low elevation of the Dead Sea. The older hypothesis is that it 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.

Around three million years ago,^{[citation needed]} what is now the valley of the Jordan River, Dead Sea, and Wadi Arabah was repeatedly inundated by waters from the Mediterranean Sea. The waters formed in a narrow, crooked bay 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 climate change. The lake that occupied the Dead Sea Rift, named "Lake Sedom",^[9] deposited beds of salt that eventually became 3 km (2 mi) thick.

Near Ein Gedi, salt builds up along the shores of the Dead Sea.

Pebbles cemented with halite on the western shore of the Dead Sea near Ein Gedi.

Approximately two million years ago,^{[citation needed]} 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 bay became a lake.

The first such prehistoric lake is named "Lake Amora"^[9] Lake Amora was a freshwater or brackish lake that extended at least 80 km (50 mi) south of the current southern end of the Dead Sea and 100 km (60 mi) north, well above the present Hula Depression. As the climate became more arid, Lake Amora shrank and became saltier. The large, saltwater predecessor of the Dead Sea is called "Lake Lisan."^[9]

In prehistoric times, 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 pail. 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 domes)

From 70,000 to 12,000 years ago, the lake level was 100 m (330 ft) to 250 m (820 ft) higher than its current level. This lake, called "Lake Lisan", fluctuated dramatically, rising to its highest level around 26,000 years ago, indicating a very wet climate in the Near East.^[10] Around 10,000 years ago, the lake level dropped dramatically, probably to levels 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.

Climate[link]

The Dead Sea's climate 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 weakened ultraviolet radiation, particularly the UVB (erythrogenic rays), and an atmosphere characterized by a high oxygen content due to the high barometric pressure.^[11] The 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 30C (86F) annually.^[12]

Chemistry[link]

Halite deposits (and teepee structure) along the western Dead Sea coast.

Beach pebbles made of halite; western Dead Sea coast.

Until the winter of 1978-79, when a major mixing event took place,^[14] the Dead Sea was composed of two stratified layers of water that differed in temperature, density, age, and salinity. The topmost 35 metres (115 ft) 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 (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).^{[citation needed]} 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.^[14]

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.^[15] 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 (common salt, NaCl) 30.4%. In comparison, the salt in the water of most oceans and seas is approximately 97% 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 sea itself is abundant in minerals acclaimed to have therapeutic value.^{[citation needed]}

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.^[16] 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.^[17][18]

Health effects and therapies[link]

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.^[19]

The region's climate and low elevation have made it a popular center for several types of therapies:

• Climatotherapy: Treatment which exploits local climatic features such as temperature, humidity, sunshine, barometric pressure and special atmospheric constituents
• Heliotherapy: Treatment that exploits the biological effects of the sun's radiation
• Thalassotherapy: Treatment that exploits bathing in Dead Sea water

Treatment for psoriasis[link]

Climatotherapy at the Dead Sea is an effective therapy for patients with the skin disease psoriasis,^[20] which 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.^[21]

Treatment for rhinosinusitis[link]

Rhinosinusitis patients receiving Dead Sea saline nasal irrigation exhibited significantly better symptom relief compared to standard hypertonic saline spray.^[22]

Treatment for osteoarthritis[link]

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 in these patients.^[23]

Panorama of the Dead Sea from observation point in the Israeli side

Panorama of the Dead Sea from observation point in the Israeli side

Panorama of the Dead Sea from the Mövenpick Resort, Jordan.

Panorama of the Dead Sea from the Israeli side

Panorama of the Dead sea from Mount Sodom.

Fauna and flora[link]

Dead Sea in the morning, seen from Masada

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% salinity 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 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 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.

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.

Human settlement[link]

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 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. Highway 65 runs north-south on the Jordanian side.

Hebrew Bible[link]

Just north 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)..."

The Jewish historian Josephus identifies the Dead Sea in geographic proximity to the ancient Biblical city of Sodom. However, he refers to the lake by its Greek name, Asphaltites.^[24]

History[link]

World's lowest (dry) point, Jordan, 1971

Second Temple period[link]

Dwelling in caves near the Dead Sea is recorded in the Hebrew Bible as having taken place before the Israelites came to Canaan, and extensively at the time of King David. 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.^[25] 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.^[26] 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.^[27]

Ancient Greek period[link]

The Greeks knew the Dead Sea as "Lake Asphaltites", due to the naturally surfacing asphalt. Aristotle wrote about the remarkable waters. Later, the Nabateans discovered the value of bitumen extracted from the Dead Sea needed by the Egyptians for embalming their mummies.

Herodian period[link]

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 70-73 CE, a small group of Jewish zealots held out against the might of the Roman legion, and Machaerus where, according to Josephus, John the Baptist was imprisoned by Herod Antipas and died.^[28]

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.

Mount Sodom, Israel, showing the so-called "Lot's Wife" pillar made of halite like the rest of the mountain.

Turkish trenches at the shores of the Dead Sea, World War I, 1917.

In the Bible, the Dead Sea is called the Salt Sea, the Sea of the Arabah, and the Eastern Sea. The designation “Dead Sea” is a modern name which never appears in the Bible. The Dead Sea basin is another part of the Great Rift Valley. It is here that the Upper Jordan River/Sea of Galilee/Lower Jordan River water system comes to an end. 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 Judean Desert, are places of pilgrimage.

Modern times[link]

Explorers and scientists arrived in the area to analyze the minerals and research the unique climate. 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 a mile inland from the northwestern shore of the Dead Sea (presently in the West Bank). They became known and famous as the Dead Sea Scrolls. A golf course named for Sodom and Gomorrah was built by the British at Kalia on the northern shore.

The world's lowest road, Highway 90, runs along the Israeli and West Bank shores of the Dead Sea at 393 m (1,289 ft) below sea level.

The first major hotels were built in nearby Arad, and since the 1960s at the Neve Zohar resort complex. On Jordanian side, three international franchises have opened seaside resort hotels near the King Hussein Bin Talal Convention Center along the eastern coast of the Dead Sea.^[29]

Industry[link]

View of salt evaporation pans on the Dead Sea, taken in 1989 from the Space Shuttle Columbia (STS-28). The southern half is separated from the northern half at what used to be the Lisan Peninsula because of the fall in level of the Dead Sea.

The dwindling water level of the dead sea

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 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 ex 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.^[30] The company quickly grew into the largest industrial site in the Middle East,^{[citation needed]} 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, but ultimately became a casualty of the 1948 Arab-Israeli War. Its remnants were nationalised and Dead Sea Works Ltd. was established in 1952 in its stead 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, Arab Potash (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 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[link]

Erosional gully in unconsolidated Dead Sea sediments exposed by recession. This gully was excavated by floods from the Judean Mountains in less than a year.

In recent decades, 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 depression of 395 m (1,296 ft) below sea level in 1970^[31] 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.^[32]

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. As of 2009, the project is in its early phases of planning, with developer and financier selection to be completed by year's end. The project is anticipated to begin detailed design in early 2010, with water delivery by 2017. Israel has expressed its support and will likely benefit from some of the water delivery to its Negev region. Some hydro-power will be collected near the Dead Sea from the dramatic change in elevation on the downhill side of the project.^{[citation needed]} In October 2009, the Jordanians announced accelerated plans to extract around 300 million cubic meters 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.^[33]

At a regional conference in July 2009, officials expressed increased concerns that water levels are dropping. Some suggested various industrial activities around the Dead Sea might need to be reduced. Others advised a range of possible environmental measures to restore conditions. This might include 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 asserted a need for strict conservation efforts. They also said agriculture should not be expanded, sustainable support capabilities should be incorporated into the area and pollution sources should be reduced.^[34]

Gallery[link]

• 

  Israeli highway beside the Dead Sea

• 

  Jordanian highway along the Dead Sea coast

• 

  Twisty coastline

• 

  Coastline (from Israel)

• 

  A rough Dead Sea, with salt deposits on cliffs

• 

  Dead Sea northern coast (Jordan)

• Deadsea sign diagram jordan.jpg

  Located in Jordan, this sign diagrams the topography of Jordan, the West Bank, Israel, and the Mediterranean Sea.

• 

  Dead Sea at dawn (from Sodom mountain, Israel)

• 

  Dead Sea at dusk (from Suwayma, Jordan)

• Dead Sea from Movenpick.jpg

  Dead Sea at dusk (from Mövenpick Resort Dead Sea, Jordan)

• 

  A tourist demonstrates the unusual buoyancy caused by high salinity

• 

  Many people believe that the mud of the Dead Sea has special healing and cosmetic uses.

• 

  Sinkholes at Mineral Beach

• 

  Cobble encrusted with halite evaporated from the Dead Sea near Ein Gedi

• MassadaDeadSea.JPG

  Dead Sea from Masada

• 

  Line painted in 1900 (at top of image) by Robert A.S. Macalister of the Palestine Exploration Fund showing the level of the Dead Sea

• 

  The Dead Sea region

• 

  Dead Sea seen from Jordan

• 

  Panorama of the Dead Sea from Masada, facing northeast. The area between the two is visible, as well as Jordan in the background.

See also[link]

• Dead Sea Canal
• Dead Sea Works
• Great Salt Lake
• List of places on land with elevations below sea level
• Two Seas Canal
• Benjamin Elazari Volcani
• World Discoveries III: Dead Sea

References[link]

Further reading[link]

• Yehouda Enzel, et al., eds (2006) New Frontiers in Dead Sea Paleoenvironmental Research, Geological Society of America, ISBN 0-8137-2401-5
• Niemi, Tina M., Ben-Avraham, Z., and Gat, J., eds., 1997, The Dead Sea: The Lake and Its Setting: N.Y., Oxford University Press, 286 p.

External links[link]

Wikimedia Commons has media related to: Dead Sea

Look up Dead Sea in Wiktionary, the free dictionary.

• Ezekiel's Water Project
• New Life Found At Dead Sea
• Go Visit Israel: Dead Sea
• Race is on to save the Dead Sea
• A Web Documentary On The Dead Sea
• Multilateral project for sustainable water management in the lower Jordan Valley

v t e Resources in Israel Resources: Oil: Heletz · Meged Natural gas: Leviathan · Sarah and Myra · Tamar · Tanin Potash: Dead Sea

A human skull, widely used as a symbol of death

Death is the term used to describe the cessation or permanent termination of all biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, suicide, murder and accidents or trauma resulting in terminal injury. All known organisms inevitably experience death.^[1] Bodies of living organisms begin to decompose shortly after death.

In human societies, the nature of death has for millennia been a concern of the world's religious traditions and of philosophical inquiry. This may include a belief in some kind of resurrection (associated with Abrahamic religions), reincarnation (associated with Dharmic religions), or that consciousness permanently ceases to exist, known as "oblivion" (often associated with atheism).^[2]

Commemoration ceremonies after death may include various mourning or funeral practices. The physical remains of a person, commonly known as a corpse or body, are usually interred whole or cremated, though among the world's cultures there are a variety of other methods of mortuary disposal.

Etymology[link]

The word death comes from Old English deað, which in turn comes from Proto-Germanic *dauþaz (reconstructed by etymological analysis).^{[citation needed]} This comes from the Proto-Indo-European stem *dheu- meaning the 'Process, act, condition of dying'.

Associated terms[link]

The concept and symptoms of death, and varying degrees of delicacy used in discussion in public forums, have generated numerous scientific, legal, and socially acceptable terms or euphemisms for death. When a person has died, it is also said he has passed away, passed on, or expired, among numerous other socially accepted, religiously specific, slang, and irreverent terms. Bereft of life, the dead person is then a corpse, cadaver, a body, a set of remains, and finally a skeleton. The terms carrion and carcass can also be used, though these more often connote the remains of non-human animals. As a polite reference to a dead person, it has become common practice to use the participle form of "decease", as in the deceased; the noun form is decedent. The ashes left after a cremation are sometimes referred to by the neologism cremains, a portmanteau of "cremation" and "remains".

Senescence[link]

A dead Eurasian Magpie

Almost all animals who survive external hazards to their biological functioning eventually die from senescence. The only known exception is the jellyfish Turritopsis nutricula, thought to be, in effect, immortal.^[3] Unnatural causes of death include suicide and homicide. From all causes, roughly 150,000 people die around the world each day.^[4]

Physiological death is now seen as a process, more than an event: conditions once considered indicative of death are now reversible.^[5] Where in the process a dividing line is drawn between life and death depends on factors beyond the presence or absence of vital signs. In general, clinical death is neither necessary nor sufficient for a determination of legal death. A patient with working heart and lungs determined to be brain dead can be pronounced legally dead without clinical death occurring. Paradoxically, as scientific knowledge and medicine advance, a precise medical definition of death becomes more problematic.^[6]

Signs of death[link]

Signs of death or strong indications that an animal is no longer alive are:

• Cessation of breathing
• Cardiac arrest (No pulse)
• Pallor mortis, paleness which happens in the 15–120 minutes after death
• Livor mortis, a settling of the blood in the lower (dependent) portion of the body
• Algor mortis, the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
• Rigor mortis, the limbs of the corpse become stiff (Latin rigor) and difficult to move or manipulate
• Decomposition, the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor.

Diagnosis[link]

Problems of definition[link]

A flower, a skull and an hourglass stand for Life, Death and Time in this 17th-century painting by Philippe de Champaigne

French - 16th/17th century ivory pendant, Monk and Death, recalling mortality and the certainty of death (Walters Art Museum)

The concept of death is a key to human understanding of the phenomenon.^[7] There are many scientific approaches to the concept. For example, brain death, as practiced in medical science, defines death as a point in time at which brain activity ceases.^{[7][8][9][10]} One of the challenges in defining death is in distinguishing it from life. As a point in time, death would seem to refer to the moment at which life ends. However, determining when death has occurred requires drawing precise conceptual boundaries between life and death. This is problematic because there is little consensus over how to define life. It is possible to define life in terms of consciousness. When consciousness ceases, a living organism can be said to have died. One of the notable flaws in this approach, however, is that there are many organisms which are alive but probably not conscious (for example, single-celled organisms). Another problem with this approach is in defining consciousness, which has many different definitions given by modern scientists, psychologists and philosophers. This general problem of defining death applies to the particular challenge of defining death in the context of medicine.

Other definitions for death focus on the character of cessation of something.^[11] In this context "death" describes merely the state where something has ceased, for example, life. Thus, the definition of "life" simultaneously defines death.

Historically, attempts to define the exact moment of a human's death have been problematic. Death was once defined as the cessation of heartbeat (cardiac arrest) and of breathing, but the development of CPR and prompt defibrillation have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted. Events which were causally linked to death in the past no longer kill in all circumstances; without a functioning heart or lungs, life can sometimes be sustained with a combination of life support devices, organ transplants and artificial pacemakers.

Today, where a definition of the moment of death is required, doctors and coroners usually turn to "brain death" or "biological death" to define a person as being clinically dead; people are considered dead when the electrical activity in their brain ceases. It is presumed that an end of electrical activity indicates the end of consciousness. However, suspension of consciousness must be permanent, and not transient, as occurs during certain sleep stages, and especially a coma. In the case of sleep, EEGs can easily tell the difference.

However, the category of "brain death" is seen by some scholars to be problematic. For instance, Dr. Franklin Miller, senior faculty member at the Department of Bioethics, National Institutes of Health, notes: "By the late 1990s, however, the equation of brain death with death of the human being was increasingly challenged by scholars, based on evidence regarding the array of biological functioning displayed by patients correctly diagnosed as having this condition who were maintained on mechanical ventilation for substantial periods of time. These patients maintained the ability to sustain circulation and respiration, control temperature, excrete wastes, heal wounds, fight infections and, most dramatically, to gestate fetuses (in the case of pregnant "brain-dead" women)."^[12]

Those people maintaining that only the neo-cortex of the brain is necessary for consciousness sometimes argue that only electrical activity should be considered when defining death. Eventually it is possible that the criterion for death will be the permanent and irreversible loss of cognitive function, as evidenced by the death of the cerebral cortex. All hope of recovering human thought and personality is then gone given current and foreseeable medical technology. However, at present, in most places the more conservative definition of death – irreversible cessation of electrical activity in the whole brain, as opposed to just in the neo-cortex – has been adopted (for example the Uniform Determination Of Death Act in the United States). In 2005, the Terri Schiavo case brought the question of brain death and artificial sustenance to the front of American politics.

Even by whole-brain criteria, the determination of brain death can be complicated. EEGs can detect spurious electrical impulses, while certain drugs, hypoglycemia, hypoxia, or hypothermia can suppress or even stop brain activity on a temporary basis. Because of this, hospitals have protocols for determining brain death involving EEGs at widely separated intervals under defined conditions.

In certain cultures, death is more of a process than a single event. It implies a slow shift from one spiritual state to another.^[13]

Legal[link]

In the United States, a person is dead by law if a Statement of Death or Death certificate is approved by a licensed medical practitioner. Various legal consequences follow death, including the removal from the person of what in legal terminology is called personhood.

The possession of brain activities, or capability to resume brain activity, is a necessary condition to legal personhood in the United States. "It appears that once brain death has been determined ... no criminal or civil liability will result from disconnecting the life-support devices." (Dority v. Superior Court of San Bernardino County, 193 Cal.Rptr. 288, 291 (1983))

Misdiagnosed[link]

There are many anecdotal references to people being declared dead by physicians and then "coming back to life", sometimes days later in their own coffin, or when embalming procedures are about to begin. From the mid-18th century onwards, there was an upsurge in the public's fear of being mistakenly buried alive,^[14] and much debate about the uncertainty of the signs of death. Various suggestions were made to test for signs of life before burial, ranging from pouring vinegar and pepper into the corpse's mouth to applying red hot pokers to the feet or into the rectum.^[15] Writing in 1895, the physician J.C. Ouseley claimed that as many as 2,700 people were buried prematurely each year in England and Wales, although others estimated the figure to be closer to 800.^[16]

In cases of electric shock, cardiopulmonary resuscitation (CPR) for an hour or longer can allow stunned nerves to recover, allowing an apparently dead person to survive. People found unconscious under icy water may survive if their faces are kept continuously cold until they arrive at an emergency room.^[17] This "diving response", in which metabolic activity and oxygen requirements are minimal, is something humans share with cetaceans called the mammalian diving reflex.^[17]

As medical technologies advance, ideas about when death occurs may have to be re-evaluated in light of the ability to restore a person to vitality after longer periods of apparent death (as happened when CPR and defibrillation showed that cessation of heartbeat is inadequate as a decisive indicator of death). The lack of electrical brain activity may not be enough to consider someone scientifically dead. Therefore, the concept of information theoretical death has been suggested as a better means of defining when true death occurs, though the concept has few practical applications outside of the field of cryonics.

There have been some scientific attempts to bring dead organisms back to life, but with limited success.^[18] In science fiction scenarios where such technology is readily available, real death is distinguished from reversible death.

Causes[link]

The leading cause of death in developing countries is infectious disease. The leading causes of death in developed countries are atherosclerosis (heart disease and stroke), cancer, and other diseases related to obesity and aging. These conditions cause loss of homeostasis, leading to cardiac arrest, causing loss of oxygen and nutrient supply, causing irreversible deterioration of the brain and other tissues. Of the roughly 150,000 people who die each day across the globe, about two thirds die of age-related causes.^[4] In industrialized nations, the proportion is much higher, reaching 90%.^[4] With improved medical capability, dying has become a condition to be managed. Home deaths, once commonplace, are now rare in the developed world.

The body of Pope John Paul II lying in state in St. Peter's Basilica, 2005

In developing nations, inferior sanitary conditions and lack of access to modern medical technology makes death from infectious diseases more common than in developed countries. One such disease is tuberculosis, a bacterial disease which killed 1.7 million people in 2004.^[19] Malaria causes about 400–900 million cases of fever and 1–3 million deaths annually.^[20] AIDS death toll in Africa may reach 90–100 million by 2025.^[21][22]

According to Jean Ziegler, who was the United Nations Special reporter on the Right to Food from 2000 to March 2008, mortality due to malnutrition accounted for 58% of the total mortality rate in 2006. Ziegler says worldwide approximately 62 million people died from all causes and of those deaths more than 36 million died of hunger or diseases due to deficiencies in micronutrients.^[23]

Tobacco smoking killed 100 million people worldwide in the 20th century and could kill 1 billion people around the world in the 21st century, a WHO Report warned.^[24][25]

Many leading developed world causes of death can be postponed by diet and physical activity, but the accelerating incidence of disease with age still imposes limits on human longevity. The evolutionary cause of aging is, at best, only just beginning to be understood. It has been suggested that direct intervention in the aging process may now be the most effective intervention against major causes of death.^[26]

Autopsy[link]

An autopsy, also known as a postmortem examination or an obduction, is a medical procedure that consists of a thorough examination of a human corpse to determine the cause and manner of a person's death and to evaluate any disease or injury that may be present. It is usually performed by a specialized medical doctor called a pathologist.

An autopsy is portrayed in The Anatomy Lesson of Dr. Nicolaes Tulp, by Rembrandt

Autopsies are either performed for legal or medical purposes. A forensic autopsy is carried out when the cause of death may be a criminal matter, while a clinical or academic autopsy is performed to find the medical cause of death and is used in cases of unknown or uncertain death, or for research purposes. Autopsies can be further classified into cases where external examination suffices, and those where the body is dissected and an internal examination is conducted. Permission from next of kin may be required for internal autopsy in some cases. Once an internal autopsy is complete the body is generally reconstituted by sewing it back together. Autopsy is important in a medical environment and may shed light on mistakes and help improve practices.

A "necropsy" is an older term for a postmortem examination, unregulated, and not always a medical procedure. In modern times the term is more often used in the postmortem examination of the corpses of animals.

Life extension[link]

Life extension refers to an increase in maximum or average lifespan, especially in humans, by slowing down or reversing the processes of aging. Average lifespan is determined by vulnerability to accidents and age or lifestyle-related afflictions such as cancer, or cardiovascular disease. Extension of average lifespan can be achieved by good diet, exercise and avoidance of hazards such as smoking. Maximum lifespan is determined by the rate of aging for a species inherent in its genes. Currently, the only widely recognized method of extending maximum lifespan is calorie restriction. Theoretically, extension of maximum lifespan can be achieved by reducing the rate of aging damage, by periodic replacement of damaged tissues, or by molecular repair or rejuvenation of deteriorated cells and tissues.

Researchers of life extension are a subclass of biogerontologists known as "biomedical gerontologists". They try to understand the nature of aging and they develop treatments to reverse aging processes or to at least slow them down, for the improvement of health and the maintenance of youthful vigor at every stage of life. Those who take advantage of life extension findings and seek to apply them upon themselves are called "life extensionists" or "longevists". The primary life extension strategy currently is to apply available anti-aging methods in the hope of living long enough to benefit from a complete cure to aging once it is developed.

Location[link]

Before about 1930, most people died in their own homes, surrounded by family, and comforted by clergy, neighbors, and doctors making house calls.^[27] By the mid-20th century, half of all Americans died in a hospital.^[28] By the start of the 21st century, only about 20 to 25% of people in developed countries died outside of a medical institution.^[28][29][30] The shift away from dying at home, towards dying in a professionalized medical environment, has been termed the "Invisible Death".^[28]

Society and culture[link]

The regent duke Charles (later king Charles IX of Sweden) insulting the corpse of Klaus Fleming. Albert Edelfelt, 1878.

Dead bodies can be mummified either naturally, as this one from Guanajuato, or by intention, as those in ancient Egypt.

Death is the center of many traditions and organizations; customs relating to death are a feature of every culture around the world. Much of this revolves around the care of the dead, as well as the afterlife and the disposal of bodies upon the onset of death. The disposal of human corpses does, in general, begin with the last offices before significant time has passed, and ritualistic ceremonies often occur, most commonly interment or cremation. This is not a unified practice; in Tibet, for instance, the body is given a sky burial and left on a mountain top. Proper preparation for death and techniques and ceremonies for producing the ability to transfer one's spiritual attainments into another body (reincarnation) are subjects of detailed study in Tibet.^[31] Mummification or embalming is also prevalent in some cultures, to retard the rate of decay.

Legal aspects of death are also part of many cultures, particularly the settlement of the deceased estate and the issues of inheritance and in some countries, inheritance taxation.

Gravestones in Kyoto, Japan

Capital punishment is also a culturally divisive aspect of death. In most jurisdictions where capital punishment is carried out today, the death penalty is reserved for premeditated murder, espionage, treason, or as part of military justice. In some countries, sexual crimes, such as adultery and sodomy, carry the death penalty, as do religious crimes such as apostasy, the formal renunciation of one's religion. In many retentionist countries, drug trafficking is also a capital offense. In China human trafficking and serious cases of corruption are also punished by the death penalty. In militaries around the world courts-martial have imposed death sentences for offenses such as cowardice, desertion, insubordination, and mutiny.^[32]

Death in warfare and in suicide attack also have cultural links, and the ideas of dulce et decorum est pro patria mori, mutiny punishable by death, grieving relatives of dead soldiers and death notification are embedded in many cultures. Recently in the western world, with the supposed increase in terrorism following the September 11 attacks, but also further back in time with suicide bombings, kamikaze missions in World War II and suicide missions in a host of other conflicts in history, death for a cause by way of suicide attack, and martyrdom have had significant cultural impacts.

Suicide in general, and particularly euthanasia, are also points of cultural debate. Both acts are understood very differently in different cultures. In Japan, for example, ending a life with honor by seppuku was considered a desirable death, whereas according to traditional Christian and Islamic cultures, suicide is viewed as a sin. Death is personified in many cultures, with such symbolic representations as the Grim Reaper, Azrael and Father Time.

In biology[link]

After death the remains of an organism become part of the biogeochemical cycle. Animals may be consumed by a predator or a scavenger. Organic material may then be further decomposed by detritivores, organisms which recycle detritus, returning it to the environment for reuse in the food chain. Examples of detritivores include earthworms, woodlice and dung beetles.

Microorganisms also play a vital role, raising the temperature of the decomposing matter as they break it down into yet simpler molecules. Not all materials need to be decomposed fully, however. Coal, a fossil fuel formed over vast tracts of time in swamp ecosystems, is one example.

Natural selection[link]

Contemporary evolutionary theory sees death as an important part of the process of natural selection. It is considered that organisms less adapted to their environment are more likely to die having produced fewer offspring, thereby reducing their contribution to the gene pool. Their genes are thus eventually bred out of a population, leading at worst to extinction and, more positively, making the process possible, referred to as speciation. Frequency of reproduction plays an equally important role in determining species survival: an organism that dies young but leaves numerous offspring displays, according to Darwinian criteria, much greater fitness than a long-lived organism leaving only one.

Extinction[link]

A dodo, the bird that became a byword in English for species extinction^[33]

Extinction is the cessation of existence of a species or group of taxa, reducing biodiversity. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point). Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where species presumed extinct abruptly "reappear" (typically in the fossil record) after a period of apparent absence. New species arise through the process of speciation, an aspect of evolution. New varieties of organisms arise and thrive when they are able to find and exploit an ecological niche – and species become extinct when they are no longer able to survive in changing conditions or against superior competition.

Evolution of ageing[link]

Inquiry into the evolution of aging aims to explain why so many living things and the vast majority of animals weaken and die with age (a notable exception being hydra, which may be biologically immortal). The evolutionary origin of senescence remains one of the fundamental puzzles of biology. Gerontology specializes in the science of human aging processes.

See also[link]

References[link]