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River Reach

River discharge in the Northern Hemisphere summer is captured in this frame from an animation that displays average weekly runoff to the ocean from the world’s major rivers using data from the Global Runoff Data Centre. Even in dry seasons, rivers are major carriers of nutrients, contaminants, and carbon from land to ocean. As a result, changes on land also lead to changes in river chemistry that ultimately affect the coastal ocean. Large rivers such as the Amazon, which drains an area the size of the Arctic ice cap and discharges more than 55 million gallons of water per second into the Atlantic, can also have an effect on the ocean hundreds of miles from its mouth.(Interactive by Martin Burch, Woods Hole Oceanographic Institution and Greg Fiske, Woods Hole Research Center)