Upwelling is a process in which deep, cold water rises toward the surface. Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away.
- Upwelling occurs in the open ocean and along coastlines. Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients fertilize surface waters meaning that these surface waters of often have high biological productivity. Therefore good fishing grounds are typically found where upwelling is common.
- The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.