The Dead Sea: A Lake That's Also a Sea

The Dead Sea defies simple classification: it is technically an endorheic lake (no outlet to the ocean) but is called a "sea" due to its extreme salinity and mineral content, which resemble ocean water.

Why It's a Lake

• Landlocked: Borders Jordan, Israel, and the West Bank; fed mainly by the Jordan River.
• No Outlet: Water leaves only by evaporation, concentrating salts and minerals.
• Geology: Sits in the Jordan Rift Valley, a tectonic depression over 430 m (1,410 ft) below sea level—the lowest land elevation on Earth.

Why It's Called a Sea

• Salinity: ~34% salinity (almost 10× ocean water), allowing effortless floating.
• Mineral Composition: Rich in magnesium, potassium, calcium, and bromide—similar to seawater but in extreme concentrations.
• Size: ~605 km² (234 sq mi), large enough to be considered a sea historically.

Unique Environment

Its hypersaline waters support only specialised microbes (halophilic archaea and algae). The mineral-rich mud and water are renowned for therapeutic and cosmetic uses.

Geographically a lake, chemically a sea—the Dead Sea occupies a category of its own.