earthstory:

Avulsion

This beautiful gif was prepared using data from the long-lived Landsat series of earth orbiting satellites, You are looking at the course of the Padma River in Bangladesh and how its course has varied over the last 30 years. This is a textbook example of river erosion processes. When rivers begin to meander, they evolve by growing their meanders wider, until the meander finally gets too sinuous and the river finds another path. Pick a point where the river bends and watch what happens – the outer bank of the river erodes and sediment deposits on the inner side of the curve, making the river arc farther outwards. The outer side of the river that is eroding is called a cut bank, and sediment is deposited on the inside of the river building a point bar.

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