Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution.
What is the difference between chemical erosion and physical erosion?
Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.
What causes mechanical weathering and erosion?
Mechanical weathering may be caused by frost, ice, plant roots, running water, or heat from the sun. Once the small pieces of rocks are changed or broken apart by weathering, they may start to be moved by wind, water, or ice. When the smaller rock pieces (now pebbles, sand or soil) are moved by these natural forces, it is called erosion.
What is erosion?
Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water. A similar process, weathering, breaks down or dissolve s rock, but does not involve movement.
What is an example of chemical erosion?
Another familiar form of chemical erosion is hydrolysis. In the process of hydrolysis, a new solution (a mixture of two or more substances) is formed as chemicals in rock interact with water. In many rocks, for example, sodium minerals interact with water to form a saltwater solution.
Is erosion mechanical weathering?
Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity. Mechanical weathering physically breaks up rock. One example is called frost action or frost shattering. Water gets into cracks and joints in bedrock.
Is erosion a chemical reaction?
Physical Erosion Physical erosion describes the process of rocks changing their physical properties without changing their basic chemical composition.
Is erosion physical or chemical?
Erosion is the process where rocks are broken down by natural forces such as wind or water. There are two main types of erosion: chemical and physical. Chemical erosion occurs when a rock's chemical composition changes, such as when iron rusts or when limestone dissolves due to carbonation.
Is erosion a chemical weathering?
Chemical weathering occurs when minerals in rock react with water. These chemical reactions physically weaken rock by altering its structure. Rocks in streambeds then become more susceptible to erosion by physical processes, such as impacts by sediment carried in flowing water.
What is mechanical erosion?
Mechanical weathering is the process of breaking a large rock into smaller pieces without changing the minerals in the rock. Mechanical weathering may be caused by frost, ice, plant roots, running water, or heat from the sun.
What causes erosion?
What Causes Erosion? Soil erosion occurs primarily when dirt is left exposed to strong winds, hard rains, and flowing water. In some cases, human activities, especially farming and land clearing, leave soil vulnerable to erosion.
What is an example of mechanical weathering?
Mechanical weathering involves mechanical processes that break up a rock: for example, ice freezing and expanding in cracks in the rock; tree roots growing in similar cracks; expansion and contraction of rock in areas with high daytime and low nighttime temperatures; cracking of rocks in forest fires, and so forth.
What are the types of erosion?
The main forms of erosion are:surface erosion.fluvial erosion.mass-movement erosion.streambank erosion.
Which causes physical or mechanical weathering?
Physical, or mechanical, weathering happens when rock is broken through the force of another substance on the rock such as ice, running water, wind, rapid heating/cooling, or plant growth. Chemical weathering occurs when reactions between rock and another substance dissolve the rock, causing parts of it to fall away.
Is erosion a type of weathering?
Erosion and weathering are the processes in which the rocks are broken down into fine particles. Erosion is the process in which rock particles are carried away by wind and water. Weathering, on the other hand, degrades the rocks without displacing them.
Which process is a form of mechanical weathering?
The main process in mechanical weathering is abrasion, a physical process by which rocks and clasts are reduced in size. Abrasion by ice, water, and wind processes loaded with sediments can have immense cutting power. The world's greatest gorges, valleys, and ravines are largely a result of abrasion.
What are the main types of chemical weathering?
There are different types of chemical weathering processes, such as solution, hydration, hydrolysis, carbonation, oxidation, reduction, and chelation. Some of these reactions occur more easily when the water is slightly acidic.
What is an example of chemical erosion?
Some examples of chemical weathering are rust, which happens through oxidation and acid rain, caused from carbonic acid dissolves rocks. Other chemical weathering, such as dissolution, causes rocks and minerals to break down to form soil.
What is the process of erosion?
Erosion is the process by which the surface of the Earth gets worn down. Erosion can be caused by natural elements such as wind and glacial ice. But anyone who has ever seen a picture of the Grand Canyon knows that nothing beats the slow steady movement of water when it comes to changing the Earth.
What are the examples of chemical weathering?
Chemical Weathering From Oxygen One example of this type of weathering is rust formation, which occurs when oxygen reacts with iron to form iron oxide (rust). Rust changes the color of the rocks, plus iron oxide is much more fragile than iron, so the weathered region becomes more susceptible to breakage.
What are the agents of erosion?
Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows.
What are the human activities that can cause erosion?
Intensive agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils.
How does gully erosion occur?
Gully erosion occurs when runoff water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow, remo ving soil to a considerable depth. A gully is distinguished from a rill based on a critical cross-sectional area of at least one square foot, i.e. the size of a channel that can no longer be erased via normal tillage operations.
What are the causes of land degradation?
Water and wind erosion are the two primary causes of land degradation; combined, they are responsible for about 84% of the global extent of degraded land, making excessive erosion one of the most significant environmental problems worldwide.
How much has erosion increased?
While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At agriculture sites in the Appalachian Mountains, intensive farming practices have caused erosion at up to 100 times the natural rate of erosion in the region.
What is the process of removing soil and rock?
Natural processes that remove soil and rock. For other uses, see Erosion (disambiguation). An actively eroding rill on an intensively-farmed field in eastern Germany. In earth science, erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, ...
Why is valley erosion occurring?
Valley erosion is occurring due to the flow of the stream, and the boulders and stones (and much of the soil) that are lying on the stream's banks are glacial till that was left behind as ice age glaciers flowed over the terrain. Layers of chalk exposed by a river eroding through them.
What causes erosion in fields?
Erosion in fields caused by wind blowing loose soil
What is mechanical weathering caused by?
Chemical and mechanical weathering, caused by rain and wind
What is the process of breaking up a rock?
Weathering may be caused by the action of water, air, chemicals, plants, or animals. Chemical weathering involves chemical changes in the minerals of the rock, or on the surface of the rock, that make the rock change its shape or color. Carbon dioxide, oxygen, water, and acids may all cause chemical weathering . Mechanical weathering is the process of breaking a large rock into smaller pieces without changing the minerals in the rock. Mechanical weathering may be caused by frost, ice, plant roots, running water, or heat from the sun.
What is the term for mechanical weathering?
Mechanical weathering called exfoliation, causing the rocks to break into layers
What is it called when a rock is broken apart by weathering?
When the smaller rock pieces (now pebbles, sand or soil) are moved by these natural forces, it is called erosion .
What is it called when a rock is broken but stays where it is?
So, if a rock is changed or broken but stays where it is, it is called weathering . If the pieces of weathered rock are moved away, it is called erosion.
Overview
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with c…
Physical processes
Rainfall, and the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, and gully erosion. Splash erosion is generally seen as the first and least severe stage in the soil erosion process, which is followed by sheet erosion, then rill erosion and finally gully erosion (the most severe of the four).
Factors affecting erosion rates
The amount and intensity of precipitation is the main climatic factor governing soil erosion by water. The relationship is particularly strong if heavy rainfall occurs at times when, or in locations where, the soil's surface is not well protected by vegetation. This might be during periods when agricultural activities leave the soil bare, or in semi-arid regions where vegetation is naturally sparse. Wind erosion requires strong winds, particularly during times of drought when vegetatio…
Erosion at various scales
Mountain ranges are known to take many millions of years to erode to the degree they effectively cease to exist. Scholars Pitman and Golovchenko estimate that it takes probably more than 450 million years to erode a mountain mass similar to the Himalaya into an almost-flat peneplain if there are no major sea-level changes. Erosion of mountains massifs can create a pattern of equally high summits called summit accordance. It has been argued that extension during post-orogenic colla…
See also
• Bridge scour – Removal of sediment from around bridge abutments or piers by the movement of water
• Cellular confinement – Confinement system used in construction and geotechnical engineering
• Groundwater sapping
Further reading
• Boardman, John; Poesen, Jean, eds. (2007). Soil Erosion in Europe. Chichester: John Wiley & Sons. ISBN 978-0-470-85911-7.
• Montgomery, David (2008). Dirt: The Erosion of Civilizations (1st ed.). University of California Press. ISBN 978-0-520-25806-8.
• Montgomery, D.R. (8 August 2007). "Soil erosion and agricultural sustainability". Proceedings of the National Academy of Sciences. 104 (33): 13268–13272. Bibcode:
• Boardman, John; Poesen, Jean, eds. (2007). Soil Erosion in Europe. Chichester: John Wiley & Sons. ISBN 978-0-470-85911-7.
• Montgomery, David (2008). Dirt: The Erosion of Civilizations (1st ed.). University of California Press. ISBN 978-0-520-25806-8.
• Montgomery, D.R. (8 August 2007). "Soil erosion and agricultural sustainability". Proceedings of the National Academy of Sciences. 104 (33): 13268–13272. Bibcode:2007PNAS..10413268M. doi:10.1073/pnas.0611508104. PMC 1…
External links
• The Soil Erosion Site
• International Erosion Control Association
• Soil Erosion Data in the European Soil Portal
• USDA National Soil Erosion Laboratory