Deposition refers to the process of depositing material onto its original transport medium from its source, including natural processes like sediment accumulation in rivers and chemical vapor deposition.
Once small particles of Earth become weathered and weathered away by erosion, they may be transported around by erosion until finally their energy runs out, at which point erosion stops and deposition occurs.
Weathering
Weathering is the natural process of disintegrating rocks, soils and minerals when exposed to air, water, ice or living organisms; unlike erosion this does not involve moving sediment.
Physical weathering involves the gradual breaking down of rocks through processes such as erosion, frost wedging, volume changes caused by water entering cracks and freezing when it expands; plant roots also penetrate rock surfaces which contributes to physical weathering. Mechanical weathering refers to this same process.
Chemical weathering refers to the breakdown of rocks by chemical processes like dissolution and conversion into clays. Igneous rocks with interlocking silicate grains slowly decay along their crystal boundaries until their interlocking silicate grains dissolve, similar to how coffee grounds dissolve when exposed to hot water.
Length of exposure is one of the key determinants of weathering and erosion vulnerability for rocks exposed to the elements. Rocks covered by subsequent lava flows, for instance, are less likely to become damaged over time than those left exposed for prolonged periods.
Erosion
Erosion is a natural process that slowly wears away Earth’s landforms over time, moving rock, soil and minerals with wind, water, ice and gravity from one location to the next.
Weathering causes tiny pieces of rock to break off and are carried away by erosion until eventually being deposited elsewhere, called deposition. This may occur as nearby as when rain washes debris downhill or further away such as when sediment enters rivers.
Size, weight, and shape all have an effect on how quickly particles settle; larger and heavier particles tend to settle more slowly than lighter, smaller ones. Plants, hills, buildings and other objects can halt erosion by slowing or redirecting its flow of materials eroded from nearby hills or buildings; the give-and-take nature of erosion-deposition helps the environment remain balanced; however, excess erosion can create serious issues, such as desertification and agricultural productivity loss due to land degradation as well as water quality issues caused by sedimentation.
Pollution
Air pollution is the greatest environmental threat to human health, leading to millions of annual deaths worldwide from cardiovascular and respiratory conditions such as emphysema. Furthermore, it harms plants and animals as well as buildings; much of this pollution originates from industrial processes, cars and cigarette smoke emissions or natural causes like wildfires, volcanic eruptions or dust storms – most often being man-made sources.
Wet deposition plays an integral part in protecting coastal waters from acidification and degradation of aquatic life, by increasing bioavailable dissolved organic carbon (DOC). Through coastal erosion and runoff water transporting sediment into estuaries where chemical processes such as diagenesis (deposit of organic material) deposit calcium carbonate that forms chalk. Wet deposition is also essential as it increases bioavailable dissolved organic carbon (DOC). This increases bioavailability thus helping prevent acidification of coastal waters and degradation of aquatic life.
Human-caused pollution is by far the primary source of pollution. This includes anything from cooking on an open fire to burning coal or oil in factories – any form of human activity which wreaks havoc with our environment and leads to an increase in harmful bacteria and fungus which contaminates food chains – ultimately reaching humans themselves.
Biodiversity
Biodiversity has become an omnipresent buzzword in society; from economists and ecologists, ranchers, gardeners, mayors and miners all use it in different contexts. But scientists studying biodiversity (which encompasses genetic, ecosystem and species diversity) use this term in an extremely specific manner.
Children at school understand how all levels of biodiversity interact, with one level impacting another level. A prime example is species loss which impacts ecosystems in numerous ways.
Ecosystems that contain more biodiversity can better withstand stressors like pollution or climate change, and provide services humans rely on such as food, clean water and shelter. Some ecosystem services are very dramatic – for instance a single species of fungus can decompose the nitrogen from agricultural runoff that pollutes aquatic dead zones; other examples are predators which control sea urchin populations; as well as plant species which produce oils, resins, rubber lubricants or medicines to provide services.