Erosion occurs when bits of rock and soil wear away over time and move to new places by natural forces such as water, wind or ice.
The ocean waves erode seaside cliffs, producing remarkable landforms such as wave-cut platforms and sea arches. Furthermore, erosion results in rock stacks known as ventifacts.
Weathering
Weathering, also known as erosion, refers to the breaking down of rocks on Earth’s surface. Most rocks form deep within Earth where conditions differ significantly – no pressure, low temperatures and access to oxygen and water are key ingredients of their formation; once exposed at the surface their condition quickly changes dramatically.
Physical weathering caused by heat and cold cycles, frost or crystal wedging and collision of rock fragments can weaken a rock. Chemical weathering alters its chemical composition to form substances like sand and silt which are then carried away by erosion. Exposure of rocks at surface locations increases their vulnerability to erosion; factors that may impact its rate include topography, vegetation cover and tectonic activity.
Water
Water erosion occurs when fast-flowing streams and rivers wear away their banks over time, such as when the Colorado River created the five-thousand-foot deep Grand Canyon over millions of years.
Glaciers play an enormous role in erosion. Their massive amounts of power allow them to transform rocks and soil into smooth sand or dust particles that wash away into other locations, dislodging its original material while depositing it elsewhere.
Rainfall and wind speed both play an influential role in erosion. As wind speeds increase, so too does erosion – fast-blowing winds are especially capable of creating towering sand dunes in desert regions with strong currents.
Soil erosion resistance depends on its texture, structure and levels of organic matter; loam-textured soils tend to be less vulnerable than silt or fine sands. People can limit erosion by planting trees, using natural barriers like stones to stop moving sand/mud/dirt and creating living shorelines around wetland areas.
Wind
Wind erosion differs from water erosion in that it does not break apart rock but instead picks up particles of soil and dust before carrying them away, as well as carrying rocks and sand against harder surfaces and blasting them against them; this process is called abrasion. A major form of wind erosion seen in desert environments where it forms towering dunes as well as stunning ventifacts formed of rock formations.
Wind erosion is more likely to happen in arid climates. It occurs when dry surfaces remain exposed for extended periods and when high-speed winds blow at regular intervals over the soil surface.
Erosion by wind is an ongoing challenge in many regions, diminishing land’s capacity to support food crops and other vegetation growth, depleting topsoil resources, polluting air quality and creating costly dust storms. Human activities that remove trees or plough up grasses makes land more susceptible to erosion.
Glaciers
Glaciers are immense masses of ice that cover much of the Earth’s surface. These frozen masses form from accumulation of snow and ice over extended periods, then flow downhill due to gravity. Glaciers have an incredible impact on landscapes as they traverse them sculpting it in various ways as they go.
These processes involve pluckeding and abrasion. As glaciers move across rocks, they smooth them as they slide over them while simultaneously scraping away parts that can leave behind features such as faceted clasts or long grooves called glacial striations.
When two glaciers erode an area together, it creates a moraine. If many glaciers erode an individual mountain peak simultaneously, this results in the creation of a sharp-sided peak known as a horn.
Living Things
Plants growing on dry, sandy soils help mitigate erosion by trapping and holding onto loose sand particles in their roots, and preventing it from being carried away by water or wind.
But erosion can also have negative impacts on plants. Erosion causes soil to break apart or shift shape, harming both animals and plants in its wake as well as polluting rivers and lakes with its polluted particles.
Human activities like deforestation, roads, intensive agriculture and climate change can exacerbate erosion, leading to lower crop yields and topsoil loss as well as washed fertilizers, pesticides and other chemicals into rivers and lakes, where they poison aquatic life resulting in the process of desertification.