What phenomenon involves deep, cold water rising towards the ocean's surface?

Upwelling is the phenomenon where deep, cold water rises towards the ocean's surface. This process typically occurs in regions where surface waters are displaced, allowing deeper, nutrient-rich water to come to the surface. Upwelling is a crucial ecological process because it brings nutrients that stimulate the growth of phytoplankton, forming the base of the marine food web.

This process can be driven by various factors, including wind patterns and the rotation of the Earth, which create currents that effectively pull surface water away from coastal areas or regions of high productivity. As the nutrient-rich water rises, it supports diverse marine life, leading to productive fishing areas and healthy ecosystems.