2. Erosion is the geological process in which earthen materials are
worn away and transported by natural forces such as wind or
water.
3. Erosion is the opposite of deposition, the geological process in
which earthen materials are deposited, or built up, on a
landform.
4. Most erosion is performed by liquid water, wind, or ice (usually
in the form of a glacier). If the wind is dusty, or water or glacial
ice is muddy, erosion is taking place.The brown color indicates
that bits of rock and soil are suspended in the fluid (air or
water) and being transported from one place to another.This
transported material is called sediment.
6. Liquid water is the major agent of erosion on Earth. Rain,
rivers, floods, lakes, and the ocean carry away bits of soil and
sand and slowly wash away the sediment.
7. Rainfall produces four types of soil erosion: splash erosion, sheet
erosion, rill erosion, and gully erosion.
• Splash erosion describes the impact of a falling raindrop, which can
scatter tiny soil particles as far as .6 meters (2 feet).
• Sheet erosion describes erosion caused by runoff.
• Rill erosion describes erosion that takes place as runoff develops
into discrete streams (rills).
• Finally, gully erosion is the stage in which soil particles are
transported through large channels. Gullies carry water for brief
periods of time during rainfall or snowmelt but appear as
small valleys or crevasses during dry seasons.
8.
9. Valley erosion is the process in which rushing streams and
rivers wear away their banks, creating larger and larger
valleys.
Coastal erosion—the wearing away of rocks, earth, or sand
on the beach—can change the shape of entire coastlines.
10. Wind is a powerful agent of erosion.Aeolian (wind-driven)
processes constantly transport dust, sand, and ash from one
place to another.Wind can sometimes blow sand into
towering dunes.
11. Ice, usually in the form of glaciers, can erode the earth and
create dramatic landforms. In frigid areas and on some
mountaintops, glaciers move slowly downhill and across the
land.As they move, they transport everything in their path,
from tiny grains of sand to huge boulders.
12. Human activity altering the vegetation of an area is perhaps the biggest
human factor contributing to erosion.Trees and plants hold soil in
place.When people cut down forests or plow up grasses for agriculture
and development, the soil is more vulnerable to washing or blowing
away. Landslides become more common.Water rushes over exposed
soil rather than soaking into it, causing flooding.
