Erosion is the natural process of breaking apart and transporting rocks, sediments and soil from one location to another. Deposition involves transporting these materials and depositing them at their new destination.
Erosion and deposition are both the result of many different factors, but vegetation plays an essential role in slowing erosion by holding soil particles together and holding back erosion. When people remove that vegetation for construction projects, logging, or agriculture, erosion speeds up.
Wind
Wind erosion is a widespread global hazard. It occurs where soil is left exposed and unprotected, loose, and dry, collecting fine sand particles through suspension in air currents or rolling across its surface, carrying them along for some distance; small silt and clay-sized particles travel further while larger sand-size particles tend to travel shorter distances.
Erosion caused by wind can sculpt rocks into extraordinary forms known as ventifacts. Examples of ventifacts can be seen throughout China’s Badain Jaran section of the Gobi Desert or Utah’s Arches National Park.
Wind erosion transports sediment from one location to another and deposits it, known as deposition. Some river delta soils consist almost entirely of this sediment which was carried downstream. Wind erosion is very damaging; it can erode away fields’ soil, increase farm nutrient loss, cause traffic accidents and respiratory problems, as well as disrupt businesses through higher cleaning bills, transportation delays or even sand-blasted buildings.
Water
Water erosion caused by raindrop impact and flowing water is the leading cause of soil loss. Water can detach particles from their surrounding, drag them along as it travels, deposit the loose material onto its path, then depositing it somewhere else – often creating lakes, streams, deltas or riverbeds in its wake.
Physical erosion from waves and abrasion changes the shape of rocks without altering their fundamental chemical makeup. It wears away soft materials like clay and silt while eating away at harder minerals such as salts and sulfates.
As water flows over Earth’s surface, it picks up bits of sediment. This slurry of sand and gravel, known as sediment transport, travels downstream in waves or streams until enough of its energy has dissipated for sediments to settle and be deposited on land surfaces.
Ice
Ice in the form of glaciers can wreak havoc upon our planet and shape breathtaking landforms. Glaciers scrape against rocks and soil as they slowly move downhill, leading to erosion as they scrape against rocks and soil en route downhill. Eroded sediment known as glacial till is found all around glaciers.
Geologists use Cosmogenic Nuclides or U-Pb dating to track the source of sediments found in glacial till, however non-uniform erosion complicates this process.
As an example, lateral moraines can store much of the sediment produced in a catchment, this means that detrital thermochronological signatures from frontal moraines may only accurately represent certain portions of it and make assessing catchment-wide exhumation rates difficult. Furthermore, nonuniform erosion may alter transfer times between bedrock and frontal moraine that impacts age-elevation distribution patterns.
Human Activity
Erosion is a natural process that creates and destroys landforms over time, driven by factors like water, wind, climate and the characteristics of rocks and soil.
Deforestation and unsustainable farming both increase erosion rates by cutting down trees that hold soil together and decrease its ability to absorb rainwater, while construction and mining activities accelerate it by shifting large amounts of earth around. Urbanization alters rainfall patterns, thus increasing sediment deposition rates in rivers and streams.
Streams are ever-evolving bodies of water whose banks vary depending on rock type and topography; for instance, earthen floodplains are more prone to erosion than rocky riverbeds. Furthermore, streams provide vital fresh water source for living creatures as part of the hydrological cycle and may contain pollutants such as oil, chemicals, metals and fertilizers carried downstream via erosion processes; moreover they may carry large loads of sediment, which could damage infrastructure if left alone for too long.