With a salinity of 342 g/kg, or 34.2% (in 2011), it is one of the world's saltiest bodies of water[8] – 9.6 times as salty as the ocean – and has a density of 1.24 kg/litre, which makes swimming similar to floating.

Multiple canal and pipeline proposals, such as the scrapped Red Sea–Dead Sea Water Conveyance project,[11] have been made to reduce its recession.

[16] It is also known in Arabic as the Sea of Lot (‏بحر لوط‎, Buhayrat,[17] Bahret, or Birket Lut)[18] from the nephew of Abraham whose wife was said to have turned into a pillar of salt during the destruction of Sodom and Gomorrah.

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.

[23] 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 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.

Thus, the long lagoon became a landlocked lake, which – due to the high evaporation rate – retreated toward the lower, southern part of the rift valley.

[23] 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.

Until the winter of 1978–79, when a major mixing event took place,[36] the Dead Sea was composed of two stratified layers of water that differed in temperature, density, age, and salinity.

Underneath a zone of transition, the lowest level of the Dead Sea had waters of a consistent 22 °C (72 °F) temperature, salinity of over 34%, and complete saturation of sodium chloride (NaCl).

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.

[42] The region's climate and low elevation have made it a popular center for assessment of putative therapies: There is evidence that the unique attenuation and spectrum of UV rays near the Dead Sea contribute to effective photoclimatherapy for psoriasis, in part because the reduced exposure to solar radiation allows for longer periods of sunbathing.

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 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 include Ein Gedi, Neve Zohar and the Israeli settlements in the Megilot Regional Council: Kalya, Mitzpe Shalem and Avnat.

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.

Before the destruction, the Dead Sea was a valley full of natural tar pits, which was called the vale of Siddim[citation needed].

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.

[49] Archaeological evidence shows multiple anchorages existing 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.

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.

[citation needed] From the seventh century onwards, the Dead Sea area entered a period of decline and its population decreased.

[57] 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.

[58] The full text of W. F. Lynch's 1849 book Narrative of the United States' Expedition to the River Jordan and the Dead Sea is available online.

[60] The 1931 census shows a sharp increase with 535 people (264 Muslims, 230 Jews, 21 Christians, 17 Druze, and three with no religion) listing "Dead Sea" as their main village/town.

[62][63] In the late 1940s and early 1950s, hundreds of Jewish 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).

[65] On November 22, 2015, the Dead Sea panorama road was included along with 40 archaeological locations in Jordan, to become live on Google Street View.

Its founder, Siberian Jewish engineer and pioneer of Lake Baikal exploitation, Moses Novomeysky, had worked for the charter for over ten years having first visited the area in 1911.

The Palestinian economy is unable to benefit from Dead Sea chemicals due to restricted access, permit issues and the uncertainties of the investment climate.

[76] As of 2021[update] Ein Gedi, on the western coast, has been subject to a large number of sinkholes appearing in the area, attributed to the decline in the water level of the Dead Sea.

Others advised environmental measures to restore conditions such as increasing the volume of flow from the Jordan River to replenish the Dead Sea.