Rivers move back and forth in a snake-like pattern causing erosion and deposition. This may cause the river to become so tightly curved that the river may take a short cut across the corners and create a loop or an oxbow lake. An oxbow lake is the explanation for the creation of Lake Manawa and Carter Lake. Deposition is the process of eroding materials into sediments then depositing them elsewhere. Deltas are areas of built up from soil dumped when a river empties into a lake or ocean.
Sand bars are offshore shoals of sand deposited with slower moving water.
Waves are formed when wind blows over calm waters and ripples are created. These ripples enlarge with time and form larger wind waves. These Ocean waves then crash into continents and are considered to be a very powerful gradational force. They wear away the sides of continents. There have been islands that were formed by volcanic action and were worn away by waves erosion in a few short years.