What Is Erosion?

Erosion is a process that describes continuous physical and chemical events which causes soil and rock on the Earth's surface to loosen and move to a new location. To understand erosion, you can think of a built snowman or sandcastle, depending on where you live. It doesn't take long before factors like wind, water, and even people can transform the snowman into a slushy pile of snow or for the sandcastle to be washed away by the ocean. Likewise, these factors cause erosion to take place on the earth's surface, effecting landforms like mountains, soil, rivers, and sea coasts.

Water Erosion

Water plays a large part in the erosion of rocks because it transports these weathered and non-weathered materials away from its primary source. The breaking down and loosening of rock and soil into smaller pieces is known as weathering. The movement of these weathered materials is erosion. Although weathering (breaking down of rock) plays a role in erosion, it is not the same as erosion itself.

Moving water, such as currents in a river or ocean, also plays a major role since it transports Earth's materials from one place to another. Rivers may be discolored by the large amounts of sediment they carry as they wind their way to the sea. Once these particles are settled and have accumulated to a new location, it is called deposition.  Water also erodes the land by the means of ocean waves and currents, and once the particles are settled and deposited (due to erosion), they are responsible for changing coastlines.

Wind Erosion

Wind carries sediment (earth particles) from place to place. It can also increase the erosional effects of water. For example, by the time a raindrop hits the soil, it can be traveling as fast as 19 mph. At this speed, it can steadfastly break down soil and rock material and make it easier for erosion to take place and transport its materials to another location. One can see the effects of wind in areas with little to no rain or land that's too dry and barren to support vegetation. An example of this are the dust bowls in the Midwest that occurred during the Great Depression.

Wind brings about the erosion of rocks driven by sand and soil particles not held tightly together nor protected by vegetation. The removal of loose sand and dry soil particles is called deflation. This wind action continues until the strength and speed of the wind can no longer move these loose particles, which end up colliding and clinging together on the land surface.

Glacial Erosion

Ice acts most powerfully as an agent of erosion in the form of glaciers. A glacier, large and slow moving, may remove and carry hundreds, thousands, and even tons of rock debris.