Caspian Sea: Largest Inland Body of Water

The Caspian Sea is the Earth’s largest inland body of water. It lies at the junction of Europe and Asia, with the Caucasus Mountains to the west and the steppes of Central Asia to the east. It is bordered by Russia to the northwest, Azerbaijan to the west, Iran to the south, Turkmenistan to the southeast and Kazakhstan to the northeast. 

Ownership of the sea’s resources is a contentious issue among its surrounding countries. The Caspian Sea is rich with oil and natural gas, making access to it a high-stakes proposition. These complicated socio-cultural and political aspects, as well as the geographic and environmental features, make the Caspian Sea an interesting subject for researchers. 

“In some ways, it connects several countries that share no land border and in other ways it serves as buffer between states of different politics and ideologies,” said Michael Kukral, author and professor of geography at the Rose-Hulman Institute of Technology in Ohio. 

Facts and figures

• Surface area: 143,244 square miles (371,000 square kilometers) 
• Maximum depth: 3,363 feet (1,025 meters)
• Average depth: 692 feet (211 m)
• Length: 640 miles (1,030 km)
• Maximum width: 270 miles (435 km)
• Minimum width: 124 miles (200 km)
• Coastline area: 4,237 miles (6,820 km)
• Water volume: 18,761 cubic miles (78,200 cubic km)
• Altitude: 72 feet below sea level (22 m below sea level). The Caspian

  A lake or a sea?

  Despite its name, the Caspian Sea can be called either a lake or a sea. Kukral refers to it as a lake, as do many scholars. It has historically been considered a sea because of its size and its saline water, but it embodies many characteristics of lakes. Much of the confusion comes because there are no internationally agreed-upon definitions for seas or lakes. 

  Seas are often defined by connection to the ocean or another sea via salt water, which the Caspian Sea is not. Seas are usually partially enclosed by land, according to the National Oceanic and Atmospheric Administration, but the Caspian Sea is entirely enclosed by land. Seas are typically salt water. While the Caspian Sea is not fresh water, its salty water is diluted by the inflow of fresh water, especially in the north. The question of whether it is a lake or a sea has political and economic ramifications, wrote Hanna Zimnitskaya in a 2011 Journal of Eurasian Studies article. If the Caspian Sea is a lake, then the United Nations and international law have no control over its waters, she wrote. If it is a sea, international organizations can have input on its use. 
   

  This is especially important because its energy resources. “Petroleum resources around and under the Caspian Sea make it an economic natural resource and a political issue of access and ownership,” Kukral said. 

  If the Caspian Sea is a lake, it contains 40 percent of all lake water in the world. “It is the world’s largest lake,” Kukral said.