OCEAN CURRENTS AROUND NEW ZEALAND
A knowledge of ocean currents is of great importance in all branches of marine work and the study of motion within the sea is the main task of physical oceanographers. Although the general pattern of surface currents is reasonably well known, the eddies and day-to-day changes found in them still require investigation. Currents which are almost as fast and as variable as those on the surface have been found well below the surface and are still far from being completely understood. A variety of forces can produce motion within the sea and there is great interplay between these forces; consequently ocean water movements are very complex. They range from small-scale currents found near shorelines, the result of wave action, to large-scale oceanic currents which are related to the wind circulation and to density differences within the sea.