Erosion
|
Erosion
|
|
Weather changes rocks with chemical and physical reactions. A chemical reaction is erosion by dissolving. Oxygen, carbon-dioxide and moisture absorb from decaying life and part of the rock changes into soil while the rest dissolves. Most chemical weathering occurs in damp regions. A physical reaction is a reaction that takes place by breaking up rocks into smaller pieces (this is more common in dry regions). Wind constantly changes the surface of rocks
causing them to have strange shapes. Water freezes and thaws which
leads to cracks in the rocks on the surface. Running water caries loose soil,
sand, gravel, and boulders to new places. These things collide on the Ice can throw chunks of sand and gravel onto the shores of small lakes. These things pile up and sometimes form sand dunes due to the wind. Rocks are worn away by ice. The Rocky Mountains and The Alps are glaciers that constantly change their surfaces. In the Ice Age, glaciers shaped the whole Northern Hemisphere. The only thing that can protect against erosion is a forest. Rain exerts a greater force if is falls on bare land than if it falls on land with soil and greenery. When rain falls it carries some of the soil with it creating gullies in barer lands. However, forests prevent this from happening because their leaves stop the rain and cause it to fall with less force. When rain hits the soil, the soil absorbs it, which also prevents erosion.
[ Title Page ] [ Physics ] [ History ] [ Chinese Architecture ] [ Labs and Experiments ] [ Interactions ] [ Photo Gallery ] [ Bibliography ] [ About the Designers ] |
|
This Page was last edited on Thursday, July 27, 2000 .
Milken
Community High School ThinkQuest |
ir way and
create new channels and streams. This can also cause canyons to be formed. The
Grand Canyon in Arizona was eroded by the Colorado River over thousands of
years. After the water erodes rocks, rivers change their courses.