Weathering and Erosion

Physical weathering Physical or mechanical weathering breaks rock into smaller pieces without altering their chemical composition. Ex) wind, water (ice), plants (roots) Frost wedging-when water seeps into cracks or joints in rock

Chemical weathering Process by which metallic elements reacts with oxygen (oxidation reaction) therefore causing a change in property Oxidation of minerals can cause the mineral to decompose and form new minerals Ex) oxidation reaction, Carbon dioxide, water

Water and chemical weathering Minerals react chemically with water Leaching-when minerals are transported to lower layers of rock Oxidation when water carries dissolved oxygen that reacts with the minerals (forms iron oxide, rust  red)

Acid precipitation Precipitation pH = 5.7 slightly acidic (carbonic acid) When fossil fuels are burned, sulfur dioxide and nitrogen oxides are released and may react with water in clouds to form nitric acid, nitrous acid, and sulfuric acid

Erosion A process in which the matereials of the Earth’s surface are loosened, dissolved, or worn away and transported from one place to another by a natural agent, such as wind, water, ice, or gravity

Preventing ErosionWeathering can not be stopped, but erosion can. The following are common ways to prevent erosion. Plant vegetation Spread Mulch Build Retaining WallsBuild Terraces

Deposition The process by which material is laid down There is a direct relationship between the velocity of the water and the size and amount of sediment it can carry. Fast moving water-carries a lot of sediment Wider water ways flow more slowly

Other Features that shape Earth Oceans –waves erode coastline Glaciers- erode mountains Wind-dust storms (desert) erode landforms