forces that shape our earth

32
Forces That Shape Forces That Shape Our Earth: Our Earth: Weathering Weathering And And Erosion Erosion

Upload: glascod

Post on 18-May-2015

9.348 views

Category:

Technology


3 download

TRANSCRIPT

Page 1: Forces that shape our earth

Forces That Shape Our Forces That Shape Our Earth:Earth:

WeatheringWeatheringAndAnd

ErosionErosion

Page 2: Forces that shape our earth

Weathering & Erosion:Weathering & Erosion:

Erosion and weathering are major Erosion and weathering are major forces that shape Earth’s surface. forces that shape Earth’s surface.

For example, the Grand Canyon For example, the Grand Canyon was formed through erosion by the was formed through erosion by the Colorado River running through it!Colorado River running through it!

Page 3: Forces that shape our earth
Page 4: Forces that shape our earth
Page 5: Forces that shape our earth

What is weathering?What is weathering?

WeatheringWeathering:: The breaking down The breaking down of rocks into smaller pieces.of rocks into smaller pieces.

1. Mechanical /Physical1. Mechanical /Physical

2. Chemical2. ChemicalHulk Rock

Smash!

Hulk Rock

Smash!

Page 6: Forces that shape our earth

So what is erosion?So what is erosion?

Erosion:Erosion:

The movementThe movement

of weathered of weathered

rock by wind, rock by wind, water, glaciers water, glaciers & gravity& gravity

Page 7: Forces that shape our earth
Page 8: Forces that shape our earth

Types of Weathering:Types of Weathering:

Mechanical/Physical:Mechanical/Physical:

Rock is physically broken into smaller Rock is physically broken into smaller pieces (larger pieces become smaller pieces (larger pieces become smaller pieces of the same rock)pieces of the same rock)

Chemical:Chemical:

Rock is chemically changed (like Rock is chemically changed (like rusting or dissolving away)rusting or dissolving away)

Page 9: Forces that shape our earth

5 Agents of 5 Agents of Mechanical Mechanical WeatheringWeathering::

1.1. Release of PressureRelease of Pressure

2.2. Freezing & ThawingFreezing & Thawing

3.3. Animal ActionsAnimal Actions

4.4. Plant GrowthPlant Growth

5.5. AbrasionAbrasion

Page 10: Forces that shape our earth

Release of PressureRelease of Pressure

As the surface of a rock is As the surface of a rock is eroded, the rock begins to release eroded, the rock begins to release pressurepressure

Causes top layers of the rock to Causes top layers of the rock to crack and flake offcrack and flake off

Page 11: Forces that shape our earth

Release of pressure: rock Release of pressure: rock cracks like an egg shellcracks like an egg shell

Page 12: Forces that shape our earth

Freezing & ThawingFreezing & ThawingWhen When waterwater in the cracks in the cracks

of rocks of rocks freezesfreezes it it expands expands causing the causing the crack tocrack to enlarge or enlarge or get get biggerbigger. The ice melts & . The ice melts & refreezes over & over, refreezes over & over, breaking the rock apart.breaking the rock apart.

Page 13: Forces that shape our earth

Result of Freezing & ThawingResult of Freezing & Thawing

Page 14: Forces that shape our earth

Animal ActionsAnimal Actions

Animals digAnimals dig (burrow) through (burrow) through the ground to make their the ground to make their homes. homes. This loosens the soil & This loosens the soil & breaks apart rocksbreaks apart rocks..

Page 15: Forces that shape our earth
Page 16: Forces that shape our earth

Plant Root GrowthPlant Root Growth

Plants Plants rootsroots can can grow into grow into cracks in the rock,cracks in the rock, slowly slowly breaking them apart.breaking them apart.

Page 17: Forces that shape our earth
Page 18: Forces that shape our earth

AbrasionAbrasion SandSand and other rock particles and other rock particles in in

wind, water or ice can wear wind, water or ice can wear awayaway exposed exposed rockrock surfaces. surfaces.

Like sandblasting or sandpaper Like sandblasting or sandpaper on woodon wood

Page 19: Forces that shape our earth
Page 20: Forces that shape our earth
Page 21: Forces that shape our earth

Chemical WeatheringChemical Weathering

The process that breaks down The process that breaks down the surface of rock by the surface of rock by chemical changes.chemical changes.

Page 22: Forces that shape our earth

5 Agents of 5 Agents of Chemical Chemical WeatheringWeathering

1.1. WaterWater

2.2. OxygenOxygen

3.3. Carbon DioxideCarbon Dioxide

4.4. Living OrganismsLiving Organisms

5.5. Acid RainAcid Rain

Page 23: Forces that shape our earth

WaterWater

Water Water dissolves rockdissolves rock

Water is the Water is the most important most important causecause of chemical weathering of chemical weathering

Page 24: Forces that shape our earth
Page 25: Forces that shape our earth

OxygenOxygenOxygen + Water + Iron = RustOxygen + Water + Iron = Rust

through the Chemical reaction through the Chemical reaction called called OxidationOxidation

Rock will become crumbly, soft, Rock will become crumbly, soft, and appear reddish-brown in colorand appear reddish-brown in color

Page 26: Forces that shape our earth

Rusted rock on hillsideRusted rock on hillside

Page 27: Forces that shape our earth

Carbon DioxideCarbon Dioxide

COCO22 + rainwater = Carbonic Acid + rainwater = Carbonic Acid

Carbonic Acid weathers softer rockCarbonic Acid weathers softer rock like limestone & marble as it seeps like limestone & marble as it seeps into spaces in rock.into spaces in rock.

Ex: sinkholes, cavesEx: sinkholes, caves

Page 28: Forces that shape our earth
Page 29: Forces that shape our earth

Living OrganismsLiving Organisms

The The roots of plants make a roots of plants make a weak acidweak acid that slowly that slowly dissolves rocks around the dissolves rocks around the plant.plant.

Page 30: Forces that shape our earth

Lichens grow on rockLichens grow on rock

Page 31: Forces that shape our earth

Acid RainAcid Rain

Acid rain Acid rain causes rocks to causes rocks to weather very rapidlyweather very rapidly..

Page 32: Forces that shape our earth