Three main natural forces bring about erosion: wind, water and ice. When water flows and moves heavily, it can cause soil erosion. Strong winds, especially in the desert, erode sand dunes. Glacial erosion has significantly shaped the surface of the earth for millions of years.
Water is the most powerful force that operates over and shapes the land. A body of water with a strong current, like a river, can erode riverbanks and transport tons of eroded soil to a lower area. It can affect a wider area when combined with wind in the form of a hurricane. The large waves and storm surges brought about by hurricanes can erode the sand dunes along the shoreline. Strong tidal current, generated by a storm and strong winds, can remove the beach and cause tidal erosion.
Wind erosion occurs in dry places, where there is loose, fine and granulated soil exposed to the elements. The wind displaces the soil by carrying it from the land surface and transporting it onto another area.
Although they seem immobile, glaciers or giant rivers of ice actually move slowly, eroding valleys and mountains as they inch down a slope. A glacier can eventually scour away a whole mountainside when the glacier moves away from the land beneath it. The land it leaves is often comprised of large mounds of gravel, mud, sand and small rocks.