Spiral oceanic surface currents which are found in both the Northern and Southern Hemispheres are called

• A. Currents
• B. Tides
• C. Gyres
• D. Eddies

Answer: (C)

Gyres are the large circular patterns of surface ocean currents that occur in every major ocean basin. They form because prevailing winds push surface waters and the Coriolis effect deflects moving water: to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection makes the flow loop into a clockwise circulation in the north and a counterclockwise one in the south, creating the spiral, basin-spanning current pattern. Tides are vertical movements driven by the Moon and Sun, not continuous surface gyres. Eddies are smaller, localized spirals, not the whole-basin systems described by gyres. So the term that fits both hemispheres for these large-scale spiral surface currents is gyres.