The Water Cycle
The diagram below shows the Earth's water cycle (also knows as
the hydrologic cycle). Image courtesey USGS.
What drives surface currents?
What drives deep-water circulation?
Currents that are density-driven (density depends on salinity
and temperature). As the solar energy does not penetrate far into
the ocean waters, the water temperature decreases rapidly between
100 and 800 meters, in a region referred to as the thermocline.
There may also be a region of rapid change in the salinity, referred
to as the halocline.
For more information on these topics, visit: Thermocline
and Halocline prepared by Don Reed of San Jose State University.