Which process brings cold, nutrient-rich water from the bottom of the ocean to the surface?

Which process brings cold, nutrient-rich water from the bottom of the ocean to the surface?

• A. Downwelling
• B. Upwelling
• C. Circulation
• D. Erosion

Answer: (B)

Upwelling is the process that brings cold, nutrient-rich water from the deep ocean up to the surface. When winds push surface waters away from a coastline, surface water moves offshore and deeper water rises to replace it. That deep water is colder and carries nutrients released from the ocean floor and decaying material, so when it reaches the surface it feeds phytoplankton and supports a burst of marine productivity. Downwelling would push surface water downward rather than bring it up, circling describes broad movement without specifying vertical transport, and erosion isn’t involved in moving water between depths.

Upwelling is the process that brings cold, nutrient-rich water from the deep ocean up to the surface. When winds push surface waters away from a coastline, surface water moves offshore and deeper water rises to replace it. That deep water is colder and carries nutrients released from the ocean floor and decaying material, so when it reaches the surface it feeds phytoplankton and supports a burst of marine productivity. Downwelling would push surface water downward rather than bring it up, circling describes broad movement without specifying vertical transport, and erosion isn’t involved in moving water between depths.