Island wake produced by Antipodes Islands south of New Zealand

SL4-137-3655 (16 Dec. 1973) --- An island wake produced by the Antipodes Islands in the ocean current south of New Zealand is seen in this photograph taken from the Skylab space station in Earth orbit. A Skylab 4 crewmen took the picture with a hand-held 70mm Hasselblad camera. The bow wave pattern is quite evident and can be used to determine the current speed from the angle of the bow wave if the propagation speed of the surface wave is known. Also, evident is the darker band extending downstream from the island tens of miles. This is the actual wake of the island. The existence of water color differences from within to outside a turbulent island wake may indicate a temperature difference, with cooler water being stirred to the surface in the wake. This temperature difference could be used to drive a thermo-electric type generator to reduce small islands' dependence on imported oil for power generation. Photo credit: NASA