Why Is the Dead Sea Called the Dead Sea?

The Dead Sea is a landlocked salt lake in the Middle East that's virtually lifeless. The Dead Sea's eastern shores belong to Jordan, while the southern and western portions belong to Israel. The northern half of the western shore is located within the West Bank. Today, the Dead Sea is a popular tourist destination and source of water for commercial applications.

How Was the Dead Sea Formed?

The Dead Sea's name comes from the waterbody's extreme saltiness, which makes it inhospitable for most life. The Dead Sea contains about 340 grams of salt in every liter of water, making it nearly 10 times saltier than seawater. The extreme saltiness of the water makes it denser than our bodies, allowing people to easily float in the Dead Sea. The Dead Sea is also the lowest point on Earth. At its surface, the Dead Sea is about 1,400 feet (430 meters) below sea level. At its deepest point, the Dead Sea is nearly 1,000 feet (300 meters) deep, or about 2,400 feet (730 meters) below sea level. The Dead Sea has become both lower and saltier in recent decades.

The Dead Sea Rift

The Dead Sea is located between two tectonic plates: the African Plate and the Arabian Plate. Between these plates are a series of faults collectively known as the Dead Sea Transform or the Dead Sea Rift. The Dead Sea Rift is made up of a series of strike-slip faults, or locations where the two plates are separating. Both the Arabian Plate and the African Plate are moving in a north-northeast direction, but the Arabian Plate is moving faster, causing separation. The Dead Sea's basin formed along the Dead Sea Rift from the movement of overlapping strike-slip faults which caused the basin to sink down.

This active fault line forms diapirs, a type of geologic intrusion that breaks through brittle surface rocks. In the Dead Sea, two diapirs of salt have formed: the Lisan Diapir and the Sedom Diapir. These salt intrusions are the main cause of the Dead Sea's extreme saltiness.

A second source of the Dead Sea's saltiness is water flow—or lack thereof. The Dead Sea's primary water supply is the Jordan River. The Dead Sea only receives about 2 inches of rainfall every year. Being so low, there's no water flow out of the Dead Sea. Instead, the Dead Sea's water evaporates, leaving behind the salt to accumulate. Today, much of the Jordan River's freshwater is diverted off-route for agriculture, among other uses. As a result, the Dead Sea's water level is falling by about 3 feet every year.

Lake Lisan

Before the Dead Sea came its precursor, Lake Lisan. Lake Lisan existed for about 55,000 years during the late Pleistocene. Estimates suggest Lake Lisan was up to 750 square miles, making it more than three times the size of the Dead Sea. Sediments left behind by Lake Lisan are found throughout the Jordan Valley today, including the shores of the Dead Sea. Together, these sediments are known as the Lisan Formation.

Lake Lisan also left behind what's now known as the Lisan Peninsula—a large salty uplift that created an incomplete divide in the Dead Sea. Due to drops in the Dead Sea's water level, the Lisan Peninsula now blocks the southern portion of the Dead Sea completely. This southern basin is now made of artificial evaporation ponds for commercial salt production.

Does Anything Live in the Dead Sea?

The Dead Sea's extreme saltiness, high levels of magnesium, and acidic conditions make the inland lake inhospitable for most life—but not all. While the Dead Sea surely does not house any fish, crabs, or other animals often associated with saltwater, bacteria, archaea, and single-celled algae have all found a way to survive the Dead Sea's extreme environment.

After abnormally rainy seasons, blooms of these microbes can occur. The type of algae that lives within the Dead Sea is thought to remain in a dormant form until unusually large rainfalls lower the concentration of salt in the Dead Sea's surface waters, allowing the algae to bloom. These blooms are composed of a less-diverse assemblage of microbes than the Dead Sea's standard. The microbes that live within the Dead Sea are likely unique to the Dead Sea—and it's unlikely that the same microbes thrive anywhere else on Earth.