Earth, wind and water combine to create the world's endless ocean currents.
As Earth hurtles around its axis at 1,000 miles per hour, its rotation sets the seas in motion and generates winds that bear down on the ocean surface. The fast-moving currents, swirling eddies and powerful drifts that result appear at first glance as a disorderly jumble of flows. Yet their movements are directed by enormous, rotating currents, called gyres, which slowly circulate water around the planet's major ocean basins. The visualizations below combine NASA satellite data with field measurements to present a modeled view of surface flows and gyres in the Northern Hemisphere from March 2007 to March 2008. Observe the dramatic difference in strength between westward and eastward currents as they hook clockwise in the Atlantic and Pacific oceans. And notice how westward currents explode into spiraling, turbulent flows off the eastern coasts of Asia and North America.