Sea, ocean, lake, pond: what are the differences?

It is not always easy to differentiate between sea, ocean, lake, and pond. Even scientists sometimes disagree on these classifications. However, a few simple characteristics of each body of water can help clarify the differences. "A vast expanse of saltwater that covers much of the Earth's surface." Dictionaries do not always differentiate between a sea and an ocean. Yet, just as there are differences between a river and a stream, a sea and an ocean have well-defined characteristics.

What are the differences between an ocean, a sea, and a lake?

Both seas and oceans are vast expanses of saltwater. They can be either cold or warm, and both can experience the tidal phenomenon, although it is more pronounced in oceans. However, three essential criteria distinguish a sea from an ocean:

An ocean is larger than a sea. The planet's largest ocean covers nearly 180 million square kilometers, while the smallest ocean covers around 14 million square kilometers. The largest sea, the Arabian Sea, measures only about 3.6 million square kilometers. An ocean is also significantly deeper than a sea. An ocean surrounds a continent and rests on a basaltic floor. A sea, on the other hand, rests on continental crust.

Lakes, on the other hand, differ from oceans and seas primarily in that they are filled with fresh water. They are isolated from the sea, fed by a river, and also have an emissary river. To qualify as a lake, a body of water must be large and deep enough - greater than 20 meters - to allow sediment to settle on its bottom and for the thermal stratification of its waters.

What are the differences between a lake, a pond, and a pool?

Unlike a lake, a pond is a shallow body of water, fresh or saltwater, typically between 5 and 10 meters deep. A pond forms by the accumulation of water that is not absorbed by impermeable soil. It is supplied by low-flow sources such as rainwater, runoff, streams, and groundwater. The water in a pond is stagnant, and its ecosystem is quite different from that of a lake.

Finally, a pool is a small body of water that is less than 2 meters deep. It can be natural (such as a forest or a prairie pool) or man-made (such as a water collection or storage pool). It is not necessarily permanent.