Dead Sea vs Great Salt Lake: The World's Saltiest Waters

The Dead Sea and the Great Salt Lake are the most famous hypersaline lakes in the world, each famous for water so salty that swimmers float effortlessly. The Dead Sea, on the Israel-Jordan border, has a salinity of about 34%, roughly 10 times saltier than the ocean. Utah's Great Salt Lake varies from 5% to 27% salinity depending on water levels.

Introduction

Both lakes have no outlet and are shrinking dramatically due to water diversions from their tributary rivers. The Dead Sea's surface has dropped over 30 meters since the 1960s, and the Great Salt Lake reached record low levels in 2022. Their crises offer parallel warnings about unsustainable water use.

Size & Geography

• Dead Sea Surface Area: ~605 km² (and shrinking)
• Great Salt Lake Area: ~4,400 km² (at average; was ~8,500 km² historically)
• Dead Sea Salinity: ~34%
• Great Salt Lake Salinity: 5-27% (varies)
• Dead Sea Elevation: -430.5 m (lowest point on Earth's surface)
• Great Salt Lake Elevation: ~1,280 m above sea level

The Great Salt Lake is far larger in area but much less saline on average. The Dead Sea compensates with extreme salt concentration, making it one of the saltiest bodies of water on Earth. The Dead Sea sits at the lowest point on Earth's surface, more than 430 meters below sea level, in the Jordan Rift Valley.

The Great Salt Lake occupies the remnant of prehistoric Lake Bonneville, which once covered 51,000 square kilometers of the Great Basin during the last ice age. The Bonneville Salt Flats, famous for land speed records, are a vestige of this ancient lake. The current lake is divided by a railroad causeway into a saltier north arm and a less saline south arm.

Dead Sea Profile

• Countries: Israel, Jordan, Palestine
• Source Rivers: Jordan River (severely depleted)
• Rate of Decline: ~1 meter per year surface drop
• Tourism: Famous for floating, mineral spa treatments

The Dead Sea has been shrinking at an alarming rate since the 1960s, losing roughly one meter of surface level per year. The Jordan River, its primary source, has been diverted by Israel, Jordan, and Syria for agriculture and drinking water, reducing inflow by over 90%. Mineral extraction operations by both Israel and Jordan also consume large quantities of water.

As the Dead Sea shrinks, sinkholes have proliferated along its shores, swallowing roads, buildings, and date palm groves. Over 6,000 sinkholes have appeared since the 1980s as underground salt deposits dissolve when groundwater fills the void left by the retreating lake. Despite these challenges, the Dead Sea remains a major tourist destination famous for its mineral-rich mud and the ability to float effortlessly in its dense water.

Great Salt Lake Profile

• State: Utah, USA
• Source Rivers: Bear, Weber, Jordan rivers
• Rate of Decline: Lost ~73% of water volume since 1987
• Ecology: Critical migratory bird habitat

The Great Salt Lake is the largest saltwater lake in the Western Hemisphere and the eighth-largest terminal lake in the world. It serves as a critical stopover for millions of migratory birds, including Wilson's phalaropes, American avocets, and eared grebes. The lake supports a brine shrimp industry worth roughly $60 million annually, providing fish food for aquaculture worldwide.

The lake reached record low levels in 2022, having lost approximately 73% of its water volume since 1987. Water diversions for agriculture and urban use in Utah's rapidly growing Wasatch Front consume most of the tributary flow. As the lakebed is exposed, toxic dust containing arsenic and mercury becomes airborne, threatening the health of 2.5 million people in the Salt Lake City metro area.

Key Differences

• Salinity: Dead Sea is much saltier (34% vs 5-27%)
• Elevation: Dead Sea is 1,710 m lower than the Great Salt Lake
• Size: Great Salt Lake is ~7x larger by area
• Ecology: Great Salt Lake supports massive bird populations; Dead Sea supports almost no life

The Dead Sea's extreme salinity means it is essentially lifeless, supporting only specialized microorganisms. The Great Salt Lake, while hypersaline, supports brine shrimp and brine flies in enormous quantities, which in turn feed millions of migratory birds. The ecological value of the Great Salt Lake is far greater.

Both lakes are terminal (no outlet), meaning they concentrate minerals from inflowing rivers. The Dead Sea contains high concentrations of magnesium, potassium, and bromine, making it a source of industrial minerals. The Great Salt Lake similarly supports a mineral extraction industry, producing magnesium chloride, potassium sulfate, and common salt.

Which Is More Impressive?

• Dead Sea Advantage: Highest salinity, lowest point on Earth, mineral-rich, ancient history
• Great Salt Lake Advantage: Larger, ecologically vital bird habitat, brine shrimp industry

The Dead Sea is a geographic superlative: the lowest point on Earth's surface, one of the saltiest bodies of water anywhere, and a place where geology and history intertwine at the crossroads of ancient civilizations. The experience of floating in water so dense that you cannot sink is unique, and the mineral spas have drawn visitors since ancient times.

The Great Salt Lake matters more ecologically. As a critical habitat for millions of migratory birds, its loss would have continental-scale consequences for bird populations. The lake also serves as a buffer against toxic dust storms that could affect the health of millions of people. Its environmental crisis is one of the most urgent in North America.

Key Facts

• The Dead Sea (~34% salinity) is far saltier than the Great Salt Lake (5-27%).
• The Dead Sea sits at -430.5 m, the lowest point on Earth's surface; the Great Salt Lake at ~1,280 m elevation.
• The Great Salt Lake is roughly 7 times larger in surface area than the Dead Sea.
• Both lakes are shrinking rapidly due to water diversions from their tributary rivers.
• The Great Salt Lake supports millions of migratory birds; the Dead Sea is essentially lifeless.

Fun Facts

• The Dead Sea's water is so dense (1.24 kg/L) that it is physically difficult to swim normally; you just float.
• The Great Salt Lake's brine shrimp eggs (cysts) are harvested and sold as fish food worldwide.
• Over 6,000 sinkholes have appeared around the Dead Sea since the 1980s as it retreats.
• Prehistoric Lake Bonneville, the Great Salt Lake's ancestor, was once as large as Lake Michigan.

Final Thoughts

The Dead Sea and Great Salt Lake are both extraordinary bodies of water facing existential crises. The Dead Sea offers extremes of salinity, elevation, and mineral concentration at the lowest point on Earth. The Great Salt Lake provides critical habitat for millions of birds and a buffer against toxic dust. Both are shrinking because humans have diverted the rivers that feed them, making their futures stark warnings about the consequences of unsustainable water use.