Containing 2900 single reefs and 71 coral islands, the Great Barrier Reef off the coast of Australia is the largest reef system in the world. In this satellite image, the Great Barrier Reef contrasts with the dark sea water due to the strong reflections of the reef material, which is rich in carbonate. Right off the coast, you can see how sediment flows into the ocean while, once it enters the open sea, its colour can no longer be distinguished from the sea water due to vortices.
Picture taken on August 6, 2004
Sensor: Terra MODIS