Rain Runoff and Ocean Water
July 17, 2018
This photo shows mud being washed out of a harbor in Auckland, New Zealand, after several hours of torrential rain. The distinction between the ordinary color of the ocean water and the brown sediment in the water is easy to detect -- a remarkably straight line separates the two. This effect is caused by the flow of the outgoing tide, as well as the slightly different temperatures between the cold ocean water (it's winter in the Southern Hemisphere) and the relatively warmer rain runoff. Photo taken on June 3, 2018.