Delta switching, also known as avulsion, is the process by which some rivers - such as the Mississippi River - change their course near their deltas. The flow of a river is controlled by its gradient, which decreases as it nears the ocean, becoming nearly zero at the delta's toe.[1] Eventually, a delta can build so far out into the ocean that its gradient becomes too low to support the river's current; an event such as a flood can cause it to break a natural levee upstream, creating a new, steeper river channel that forms another delta.[2],[3] The abandoned delta eventually subsides.[4]
References:
- ^ Marshak, Stephen. (2001) Earth: Portrait of a Planet, New York: W.W. Norton & Company, ISBN 0-393-97423-5 pp. 528-9
- ^ Stanley, Steven M. (1999) Earth System History. New York: W.H. Freeman and Company, ISBN 0-7167-2882-6 p. 136
- ^ Marshak, pp. 528-9
- ^ Stanley, p. 136
