1. density current-caused by the differences in cold and hot water and/or salty and fresh water.
2. salt water is more dense than fresh water so salt water will sink down below fresh water
3. cold water is more dense than warm water so cold water will sink down below warm water.
4. density will cause the movement of water just as surely as wind will cause movement.
5. upwelling-the vertical circulation in the ocean that brings deep, cold water to the surface.
6. upwelling brings nutrients up from the ocean floor which creates rich fishing grounds.
7. as seawater freezes, the salt is left behind causing the remaining water to be extra salty. The extra salty water is more dense and will sink, creating a density current.
8. rapid evaporation also causes density currents. When ocean water evaporates, the salt is left behind, making the remaining water salty and more dense.