Erosion, the movement of rock, soil and sediment from one place to another, is an important process in shaping the Earth's surface. Erosion creates valleys and canyons and shapes sand dunes and shorelines too. But how does erosion work? Imagine a big sand dune. Could a big gust of wind move it all at once? Probably not. But if we look closely at a dune we are likely to spot a few loose grains of sand. The wind can move these at least a little bit. Here's how erosion happens. Wind, water, glaciers and waves - erosion's agents of change - pick up loose soil, sediment and rock and deposit them someplace else.