WEATHERING AND EROSION. Processes that change the surface of the Earth n Mechanical n Mechanical or...
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Transcript of WEATHERING AND EROSION. Processes that change the surface of the Earth n Mechanical n Mechanical or...
Processes that change the Processes that change the surface of the Earthsurface of the Earth
Mechanical or Physical WeatheringMechanical or Physical Weathering Chemical WeatheringChemical Weathering ErosionErosion Tectonic Activity Tectonic Activity (volcanoes, (volcanoes,
earthquakes.etc.)earthquakes.etc.)
COMMON NATURAL FORCES COMMON NATURAL FORCES
OF CHANGEOF CHANGE
WindWind WaterWater PlantsPlants Animals (including humans)Animals (including humans)
MECHANICAL MECHANICAL WEATHERINGWEATHERING
Rocks and other materials break Rocks and other materials break apart via physical means - similar apart via physical means - similar to physical changes in chemistryto physical changes in chemistry
Chemical makeup stays the sameChemical makeup stays the same wind, burrowing animals, plants, wind, burrowing animals, plants,
iceice
CHEMICAL WEATHERINGCHEMICAL WEATHERING
Chemical reactions on the surface Chemical reactions on the surface breakdown or dissolve the minerals in breakdown or dissolve the minerals in the rock or other material - similar to the rock or other material - similar to chemical changes in chemistrychemical changes in chemistry
The chemical makeup changesThe chemical makeup changes acid rain, oxidation (rusting), plant acid rain, oxidation (rusting), plant
acids, lichen, carbonic acid (caverns)acids, lichen, carbonic acid (caverns)
EROSIONEROSION Process by which weathered Process by which weathered
materials are carried awaymaterials are carried away water, wind, ice, gravity, water, wind, ice, gravity,
humanshumans water is the MOST water is the MOST
significant force of erosionsignificant force of erosion
RIVERSRIVERSBegin as rills >> gullies >> Begin as rills >> gullies >> streams >> riversstreams >> rivers
Deposit sediment as they Deposit sediment as they lose energy - slow downlose energy - slow down
Form deltas when they reach Form deltas when they reach seas, oceans, gulfs, lakesseas, oceans, gulfs, lakes
Rivers cont.Rivers cont.
Create “V” shaped valleysCreate “V” shaped valleys Colorado River carved out Colorado River carved out
the Grand Canyon over the Grand Canyon over millions of yearsmillions of years
As they age the meanders As they age the meanders increase and oxbow lakes increase and oxbow lakes may appearmay appear
Rivers cont.Rivers cont.
Important to human Important to human activityactivity
Develops rich fertile soilsDevelops rich fertile soils Can be very destructiveCan be very destructive Provide recreation and Provide recreation and
challengeschallenges
MASS WASTING OR MASS WASTING OR MOVEMENTMOVEMENT
Gravity is the force behind mass Gravity is the force behind mass movementmovement
Landslides, mudslides, slump, Landslides, mudslides, slump, creepcreep
Water, lack of vegetation, steep Water, lack of vegetation, steep slopes can create conditions that slopes can create conditions that are ripe for mass movementare ripe for mass movement
WINDWIND Causes abrasion - sand and Causes abrasion - sand and
small particles polish and small particles polish and smooth jagged edgessmooth jagged edges
Reshapes the landscape - Reshapes the landscape - sand dunessand dunes
Can be very destructive - Can be very destructive - reach speeds over 100mphreach speeds over 100mph
GLACIERSGLACIERS Create “U” shaped valleys - Create “U” shaped valleys -
Yosemite National ParkYosemite National Park Sharp mountain peaks called Sharp mountain peaks called
Horns, Glacier Lakes Horns, Glacier Lakes (Minnesota, Great lakes)(Minnesota, Great lakes)
Move HUGE massesMove HUGE masses Studied to learn about current Studied to learn about current
and past climate changesand past climate changes
DAMS Pros and ConsDAMS Pros and Cons Prevent Prevent
floodingflooding generate generate
energyenergy create lakes, create lakes,
reservoirsreservoirs
Displace peopleDisplace people destroy habitatdestroy habitat interrupt fish interrupt fish
migrationmigration endanger wildlifeendanger wildlife change flow of change flow of
sediments andsediments and riversrivers
Human ActivitiesHuman Activities
Land Developing - Land Developing - housing, industry, housing, industry, farmingfarming
Mining of ResourcesMining of ResourcesDamming of RiversDamming of Rivers