Salt water is heavier than fresh water. The kind of model used and its complexity depends on the purpose. Models allow us to make inferences about real world processes and events. Benjamin Franklin became curious because ships could go from America to England faster than they could go from England to America. Today we are going to learn about the ocean currents.
Currents are large moving rivers of water in the ocean.
These movements of ocean water are in a particular direction. Oceans are in continual motion due to the spinning of the earth, the gravitational attraction of the moon, surface winds, and heating by the sun. Ocean currents occur on and below the ocean surface. Ocean currents on the surface are basically caused by winds. Deep ocean currents are caused by the uneven heating of ocean water by the sun.