Difference Between Lake and Sea

Lake vs Sea

Water is the lifeline of earth and all living organisms. There are many water bodies on earth such as rivers, streams, lakes, ponds, seas and oceans. While oceans are the largest water bodies of salt water, seas are subsystems of these oceans that are also salt water bodies. While the rest of the water bodies are well defined and demarcated, there is always confusion between lakes and seas as there are some seas that fit into the definition of lakes, whereas some lakes are in fact seas in themselves. This article attempts to clarify these confusions by highlighting the features of lakes and seas.

Calling seas as water bodies containing salt water does not solve confusion as there are lakes with salt water and there are seas with fresh water. There are seas that are smaller than some huge lakes of the world. To understand these anomalies, one must keep in mind that lakes are not permanent water bodies. They form and die, whereas seas are permanent on the time scale. On the other hand, some seas get cut off with the feeding ocean and with continuing fresh water getting added from rivers and other sources, salinity goes down, so much so that they contain freshwater in the last. Black Sea in this connection is one example, which has alternated between salt water body and fresh water body over geological time scale.

The confusion also arises because of the way some of the water bodies were named in earlier times by their explorers. Dead Sea and Caspian Sea are not exactly seas but lakes, but they are known as seas in the world. May be the huge size of Caspian Sea confused people and they preferred to call this lake a sea. It is enclosed by land on all sides, which is a distinguishing characteristic of a lake.

Sea is a part of the ocean that is partly surrounded by land, and has salty water. Oceans are bigger and have no identifiable boundaries. There are 4 oceans in the world but 108 seas. Lake on the other hand, is fresh water surrounded by land. The water in a lake is still while a river is always flowing. Sometimes the water can be saline depending upon the geology of the surrounding and underlying terrain.

In brief:

Difference Between Lake and Sea

• Lake is an inland water body, while sea is a part of the ocean that is surrounded by land

• Lake is smaller than sea though, there are some lakes bigger than some of the seas

• Lakes contain fresh water in general though, there are some that contain salty water

• Sea, being a part of the ocean is salt water body

• Lake is not permanent on geological scale, and get formed matures, and finally dies

• Seas are more or less permanent on geological time scale

• Much of the confusion between a lake and a sea arose because of wrong nomenclature by explorers of earlier times.