Erosion is the process of corroding or eating into something. It means to wear away or cause to diminish.
- Splash erosion - With this type, a single raindrop makes a small crater, dispersing soil. This is caused directly by rainfall.
- Sheet erosion - In sheet erosion, the movement of loosened particles of soil which is caused directly by rainfall.
- Rill erosion - This is the development of flow paths for the rain water and is caused directly by rainfall.
- Gully erosion - This is the most severe type of erosion caused directly by rainfall or melting snow and refers to areas where runoff water accumulates and flows quickly.
- Valleys, rivers and streams - This is the result of water following a linear path and erodes downward, deepening a valley, and headward, lengthening the valley.
- Bank erosion - This is the wearing away of banks of streams and rivers.
- Thermal erosion - This is caused by permafrost melting because of running water. It happens along coastlines and rivers.
- Glaciers and abrasion - Debris scrapes off some of the rock.
- Glaciers and plucking - This is when pieces of bedrock break off.
- Glaciers and ice thrusting - The glacier freezes to its bed then moves and brings sheets of frozen sediment with it.
- Floods -This is when large volumes of rushing water form vortices and extreme erosion.
- Freezing and thawing - Water in cracks freezes and expands, cracking the rock.
- Wind erosion and deflation - Wind moves loose soil.
- Wind erosion and abrasion - Wind wears down surfaces with particles in the wind.
- Gravitational erosion and mass movement - This is the movement of rock on slanted surfaces due to gravity.
- Gravitational erosion and slumping - This occurs on steep surfaces as materials slide downhill rapidly.
- Exfoliation - This occurs when rock is heated by the sun quickly. The rock expands and then later contracts, causing breaks.
- Lightning strikes - Lightning strikes heat the water in the rock which causes a steam explosion that will erode the rock.
- Hydraulic action - When air in a joint is compressed by a wave, the entrance closes and it cracks.
- Wave pounding - The energy of the waves breaks off chunks of rock.
- Abrasion - This is the wearing away of the cliffs by particles in the sea water.
- Corrosion - This is eroding due to the carbonic acid in sea water.
- Sediment - This is the movement of sediment by the prevailing current or drift.
Societal or Cultural Erosion
- A major natural disaster, such as a tsunami or hurricane, can cause a society to get out of balance.
- A rapid change in population can lead to a dark age for a society.
- Absorption into a more complex social structure usually happens gradually.
- Despecialization - This is when people become more generalized in work.
- Destratification - This is when society becomes more egalitarian.
- Decentralization - This is when power becomes decentralized.
- Destructuralization - This is when people become more self-sufficient.
- Depopulation - This is a decline in population.
- Foreign invasions - The influx of foreign visitors and their cultures can bring major changes to a society.
- The U.S. spends more on education than other countries; but, it achieves less. In 2009, the U.S. was ranked 14th in reading and 25th in mathematics.
- 25 percent of high school students do not graduate within four years.
- 25 percent of students are proficient in civics.
- Eight in ten Americans only speak English.
- 22 percent of seniors meet college ready standards in core subjects.
- 75 percent of citizens between ages 17 and 24 can’t pass military entrance exams.
Now that you know what erosion is, check out some examples of ice erosion and wind erosion.