When do deep ocean currents form

Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column.

Upwelling brings those nutrients to the surface. Those nutrient support the growth of plankton and form the base of a rich ecosystem. Upwelling also takes place along the equator between the North and South Equatorial Currents.

Winds blow the surface water north and south of the equator so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Skip to main content. The highly dense water in the deep current flows southward passed the southern edge of Africa, travels across the southern Indian Ocean, flows passed the east side of Australia, and merges into the North Pacific. Once the deep current enters the North Pacific, increasing temperatures cause a lower density in the deep water, and in turn the water becomes more buoyant and rises up to the surface again.

The surface water in the North Pacific then flows south, sliding between Asia and Australia, wraps around the southern edge of Africa again--but this time moving west--and then flows across the South Atlantic. From the South Atlantic, the water connects with the Gulf Stream and flows up north again. Once it returns to the colder, higher latitudes of the North Atlantic, the dense surface water sinks back down to the lower deep water, forms a deep current and repeats the entire cycle again.

Updated November 22, Types of Water Currents. Two Types of Ocean Currents. How Do Ocean Currents Move? Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Prev NEXT. Environmental Science. Earth Science. Fast Fact. Cite This! Print Citation. Try Our Sudoku Puzzles!