The Rise and Fall of the Dead Sea

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Genesis 14, one of the most puzzling episodes in the Bible, tells of a strange and unlikely war: Five petty kings, including the kings of Sodom and Gomorrah, rebel against an overlord king, Chedorlaomer, and his three allies. The battlefield is described both as a valley and a sea (Genesis 14:3). It is somehow pocked with pits full of heµmar (probably slime—a sticky or slippery substance) into which the kings of Sodom and Gomorrah fall during the battle (Genesis 14:10).¹ We are also told that Abraham’s nephew, Lot, is captured, together with other residents and all the property of Sodom, and is spirited away by the forces of Chedorlaomer. Abraham, who is then called Abram, musters an army that pursues and defeats the overlord kings and safely returns all the captives, including Lot, to Sodom with their plundered possessions.

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Although these passages have mystified many Biblical scholars, geologists find in them a wealth of clues about the development of one of the most remarkable natural features in the world: the Dead Sea. Indeed, an understanding of some basic facts about the geology of the Dead Sea can unlock many of the riddles of Genesis 14.

One thing about the Dead Sea is certain: Its water level has fluctuated considerably over the millennia. When the water level is relatively low, the southern basin of the lake dries up, exposing the shelf underneath. When the water level rises, the southern shelf is submerged and the shoreline around the lake is higher. Any structure, such as a port built on the edge of the lake during periods of low water levels, would then be under water. When the water subsides again, the port would again be exposed—and so would the southern shelf.

The northern basin of the lake is about 30 miles long and as much as 1,000 feet deep. The southern 045basin is dry today, but in earlier periods was half as long as the northern basin—about 15 miles—but reached a depth of only 60 feet at most. The Dead Sea is 30 percent salt—probably the highest salinity of any body of water in the world—and occupies the lowest spot on the face of the earth.

The water level of the Dead Sea fluctuates dramatically over time because of the lake’s unusual sensitivity to climatic change. Rainfall in that area is extremely scarce. The lake receives most of its water from a moister region to the north. There is no outlet from the lake; in that arid zone, the water is lost by evaporation.

During the last 4,000 years, the Dead Sea has most often been at approximately 1,300 feet below the level of the Mediterranean Sea. At about this level the southern basin dries up and the sea is confined to its northern basin. When the water rises above 1,300 feet below sea level because of increasing 046rainfall or decreasing evaporation, it inundates the south basin, instantly increasing the lake area by approximately 30 percent.

As the water spreads over a broader area, more of its surface is exposed to the air, causing an abrupt increase in evaporation. This limits the water level increase to a point that the desert climate can sustain. Similarly, when the water level drops lower than 1,300 feet below sea level and recedes from the southern basin, the surface area of the lake shrinks, quickly reducing evaporation, stabilizing the water level and preventing the Dead Sea from disappearing entirely. Although the water level fluctuates significantly over long periods of time, the geometry of the basin and the arid climate together limit the range of the fluctuations.

Is it possible to chart the history of the level of the lake? We believe it is, taking into account a combination of geomorphic, archaeological and Biblical evidence. These three kinds of evidence actually correlate quite well.

A major morphological feature sits on the southwestern shore of the southern shelf of the Dead Sea: Mount Sedom (in Arabic, Jebel Usdum)². This mountain is a long, narrow ridge, 6.8 miles long and nearly 047a mile wide, rising as high as 538 feet below Mediterranean Sea level. This ridge, consisting of salt extruded from the depths of the rift valley, has been rising since prehistoric times. It is the only such salt structure to have broken the surface in the area.³

However slight and rare, any rain that falls in this region dissolves the salt in Mount Sedom quite readily. As the water flows off the ridge, carrying the salt away, an extensive network of salt hollows and caves forms. Indeed, the largest known salt caves in the world have developed in this unique environment.⁴ Long ago, one of these caves collapsed, leaving behind a giant salt pillar popularly known as Lot’s Wife. The name refers to a later episode in the life of Lot, in which he and his family flee the destruction of Sodom and Gomorrah. The wife of Lot looks back at the town, contrary to divine instruction, and is turned into a pillar of salt (Genesis 19:17–26).

Changes in these salt caves help us determine the level of the Dead Sea at various times in the past. The salt in Mount Sedom is so soluble that, as the water level of the Dead Sea fluctuates, so do the height and shape of the caves. Old high and dry cave passages thus record ancient lake levels.⁵ Organic material (such as plant remains) collects in the caves over time and is preserved in the arid climate. This material can be 048dated by carbon 14 testing, enabling us to ascertain the sequence and dates of changing water levels.⁶

The most dramatic increase in the level of the Dead Sea occurred during the Early Bronze Age (c. 3000 B.C.E.) when it rose to at least 1,150 feet below sea level.⁷ The level then dropped dramatically to about 1,300 feet below sea level in about 2500–2000 B.C.E. At that time the cave passages in Mount Sedom were subject to what geomorphologists call entrenchment (downcutting of streambeds resulting from the falling base level of the lake): Cave passages became narrower, and deep incisions of cave floors were rapidly created. One large tree stump that was found jammed in a narrow salt canyon has been dated to 2100–1800 (calibrated) years B.C.E., thus fixing the time of incision and correspondingly the time of a dramatic drop in the level of the lake.⁸ When the lake level dropped, the southern basin was separated from the rest of the lake, and a salt layer was deposited following the evaporation of residual salt water on the now-dry southern basin. This salt layer has been detected in core samples taken from the southern basin.⁹

Not until the late Bronze Age (1500–1200 B.C.E.) did the water level rise again, once more inundating the southern basin.¹⁰ We know this from several bits of evidence: A cave passage that was formed at a higher water level produced two wood samples that were carbon-dated. Two other studies, one of morphological features of the area and the other a study of the variations in organic deposits on the delta of a wadi (winter stream) leading into the lake, correlate well with the evidence from the salt caves.¹¹

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Between about 1200 and 100 B.C.E. the level again fell. When this occurred, a cave in Mount Sodom developed a steep, narrow passage from which two wood samples were taken that provided the dating.¹²

How much did the water level of the Dead Sea vary? The chart and diagram below provide our best estimate.

Three Iron Age (1200–586 B.C.E.) archaeological sites seem to confirm this geomorphological evidence. All three were flooded at times of high water level and reappeared when the water level receded. The earliest, known as Mesad Gozal, is a typical Iron Age square fort, 65 feet on a side, located near the northern tip of Mount Sodom. The late Israeli archaeologist Yohanan Aharoni dated the pottery in the fort to the 11th to 10th centuries B.C.E.¹³ Sediment on the floor indicated that the site had been flooded by the lake. Precisely when this occurred cannot be determined by archaeology. Above the sediment was pottery dating to the Byzantine period (fourth to seventh centuries C.E.), followed by still later flooding sediment.

This tells us that the lake rose high enough to deposit sediment before the Byzantine period, but had receded enough by the Byzantine period for habitation to resume at the fort. The Iron Age floor of the fort is 1,275 feet below sea level, so the lake level was probably considerably lower when the original fort was first constructed and used.

The other two archaeological sites are both docks for boats. They were explored during the 1980s by the late Pesach Bar-Adon, who dated their origin—on the basis of pottery—to the eighth to seventh centuries B.C.E.¹⁴ One of the docks, Khirbet Mazin, also called Qasr el-Yahud, lies on the northern corner of the alluvial fan of Wadi Kidron as it discharges into the lake. To anchor boats here, the level of the lake must have been at most 1,285 feet below sea level; at higher levels, the site was inundated.

The third site, Rujm el-Bahr, sits on the northern shore of the lake. To dock boats here the lake level had to be even lower—about 1,300 feet below sea level.

We could learn more from archaeological remains on the southern shelf, but unfortunately, none have been found. It may be that such remains are buried underground, covered by more recent Dead Sea sediments. The southern shelf was covered by Dead Sea water until 1980. Today it is divided into evaporation ponds from which potash is extracted. The potential of new geophysical methods for underground exploration has not yet been fully tested. Harsh conditions on the southern shelf, however, probably limited human habitation in the past, even when the area was dry.

Here is where Biblical evidence comes into play. A careful look at the text of Genesis 14 reveals that at the time of the Patriarchs (c. 2100–1850 B.C.E.), when the battle of the kings occurred, the southern basin of the lake was completely dry—that is, the Dead Sea water level must have been lower than 1,300 feet below sea level. What’s more, by the time the narrative was written down or edited, hundreds of years later, the valley upon which the battle was fought was completely inundated.

Many scholars and historians of the ancient Near East have attempted to elucidate this puzzling text. E.A. Speiser (1902–1965), an eminent Biblical scholar, noted in his commentary on Genesis that this chapter “stands alone 050among all the accounts in the Pentateuch, if not indeed in the Bible as a whole.”¹⁵ Unable to assign it to any of the authorial strands into which many scholars have divided Genesis, Speiser instead labeled the author of this narrative an “isolated source,” which he called simply “X.”^a The language of the text indicates that the narrative draws on very old traditions; it includes archaic terms and mentions ancient nations such as Rephaim, Zuzim and Emim (See Deuteronomy 2:11, 20).

The first four of the five rebellious kings are all identified by name and by the city they rule—for example, King Bera of Sodom and King Birsha of Gomorrah. But the fifth member of the coalition is unnamed. More importantly, the city he ruled has two names. He is “king of Bela, which is Zoar” (Genesis 14:2, 8). Apparently the city changed its name at some point in the past. Once it was Bela, now it is Zoar. The same is true of other places mentioned in this chapter: “‘En Mishpat which is Kadesh” (Genesis 14:7) and “the valley of Shaweh which is the valley of the king” (Genesis 14:17).

But the most important example of a place with a changed name is the battlefield itself: “The Valley of Siddim, which is the yam ha-melah (Salt Sea)” (Genesis 14:3). That name, “Salt Sea,” is another name for the Dead Sea, which is used even today in Israel. In other words, the valley where the battle took place was, at the time the account was written or edited, a sea! The obvious candidate to fit this description is the southern portion of the Dead Sea.¹⁶

That the place was “dotted with (or, more literally, “full of”) pits of slime” (Genesis 14:10), further supports the identification of the battlefield as the then-dry southern part of the Dead Sea. Pits continuously form in this area even today as the water recedes. Sometimes pits form instantaneously when the ground suddenly collapses into a pre-existing underground void. This can be quite dangerous. On several recent occasions, people have fallen into them, much like the kings of Sodom and Gomorrah. For example, on January 3, 1998, at the ‘En Gedi camping site, the ground abruptly gave way under the feet of a 21-year-old woman, who fell into a pit 25 feet deep. She found herself sitting in the bottom of the pit, still smoking a cigarette. Fortunately, she was rescued unhurt. The camping site was later closed due to further extensive collapse of many new pits that consumed roads and even a building.

Such events shed light on the origin of the story of the “five kings against four” in Genesis 14. It must have happened at a time when the lake level was low, probably around 2000 B.C.E. The story probably was not written down until the southern part of the basin was under water, perhaps in the Late Bronze Age (1500–1200 B.C.E.).

All of this goes to show how important the physical setting can be in shaping Biblical narrative. Not only can an understanding of Dead Sea fluctuations help explain the nearby archaeological remains, it offers insights into an enigmatic Biblical text that has baffled Biblical scholars for years.

Genesis 14, one of the most puzzling episodes in the Bible, tells of a strange and unlikely war: Five petty kings, including the kings of Sodom and Gomorrah, rebel against an overlord king, Chedorlaomer, and his three allies. The battlefield is described both as a valley and a sea (Genesis 14:3). It is somehow pocked with pits full of heµmar (probably slime—a sticky or slippery substance) into which the kings of Sodom and Gomorrah fall during the battle (Genesis 14:10).1 We are also told that Abraham’s nephew, Lot, is captured, together with other residents and all the property of […]