Erosional landforms result when a force of nature interacts with an existing land area. In the process, the force of nature removes material, usually rock, gravel or sand, from the land mass. The major forces of erosion include wind, water and glaciated ice. These forces can move debris across the landscape to create new and unusual landforms.
Wind often acts as an agent of erosion. This type of erosion is most prevalent in arid places, where large rock formations are often left exposed to the elements, due to lack of vegetation. The erosive power of the wind is strongest on softer strata, especially those created from sedimentary geologic events. The Great Basin of the United States is filled with unusual rocks and terrain that have been carved by the wind. One of the major by-products of wind erosion is sand. When the sand is blown into mounds, dunes form, which can be considered an erosional landform, even though they are often unstable. Wind-created sand dunes can also be found in coastal areas.
Rain that falls on solid land is absorbed by the soil and may even percolate into the rock substrate. However, some of the water will flow downhill in the form of small streams and rivers. The resulting runoff can act as an erosional force. Moving water can erode rock surfaces and carry rock particles along with quantities of organic matter downstream. Deposits of this material can build up to form a land delta, natural river levees or flood plains.
Glaciers are created when excessive snowfall builds up over many years and creates a thick ice field. These areas of excessive ice and snow can, over time, advance and recede great distances that may amount to hundreds or even thousands of miles. As they expand or push their way forward they bring with them a large accumulation of rock, gravel and debris. When the climate warms, the ice mass retreats, leaving the debris spread over the landscape in distinctive shapes. This leftover glacial debris can create several kinds of prominent landforms, characteristic of recently glaciated areas. Drumlins, moraines, eskers and kettle lakes are some of the major erosional landforms created by glaciers.
Not only can water act as a corrosive force when it flows downhill towards the sea, but the power of coastal waves breaking on the shore can also create erosional landforms. Wave action against the shoreline can cause many types of erosional landforms, including headlands, which are formed when waves interact with a coastline, where different types of rock formations are present. The softer veins of rock will eventually wear away creating protruding masses of denser rock material, which stick out far into the sea.