Ocean Currents

Surface Currents Winds can move the top 400 meters of the ocean Transfer heat from warmer to cooler areas Can form large circular patterns called gyres north Pacific, south Pacific, north Atlantic , south Atlantic, Indian Ocean Gyres flow clockwise in Northern Hemisphere & counterclockwise in Southern Hemisphere because of the Coriolis Effect.

Surface Currents

Deep Ocean Currents Driven by differences in water density & salinity (salt content) The colder & saltier the water (ex. Polar water), the more dense it is Dense water sinks & pushes warmer water away

These movements create the great ocean conveyor belt Carries heat around the world Brings oxygen to the deep sea Moves nutrients (ex. Nitrogen, phosphorus) to the surface Sinking surface water has few nutrients but the bacteria in the deep water returns nutrients to the water This water will rise once it is warmed bringing nutrients back to the surface

Great Ocean Conveyor Belt

Summary of Importance of Ocean Currents move thermal energy, dissolved oxygen & other nutrients which helps sustain the ocean’s ecosystem Surface currents affect climate & weather systems Marine industry, trade & transport Example: Grand Banks (one of the world’s riches fishing grounds)

THE GRAND BANKS: The cold Labrador Current mixes with the warm Gulf Stream at the Grand Banks. The mixing of these waters and the shape of the ocean bottom lifts nutrients to the surface. These conditions help create great biodiversity & one of the richest fishing grounds in the world. You can find Atlantic cod, swordfish, haddock , scallop, lobster, many seabirds & sea mammals including seals, dolphins, & whales. It can also create dangerous weather conditions!