Ch. 7-Erosion

How could something so ‘natural’ be so bad? Soil erosion is natural after all. However, when we change the landscape from forest to yards, streets, farm fields, shopping centers and roads, we accelerate soil erosion.

• In the USA, soil is eroding at about seventeen times the rate at which it forms.

Process which ______ weathered material from one place to another

1.

moves

2. _________- material moved by erosion

sediment

3. - the processof eroded sediments

Depositiondropping

Mass movements

weathered fragments are moved from higher to lower elevations by gravity

4.

landslides- varying sized

quickly

down a steep cliff or slope

A.

rocks and soil fall

Landslides-combination of any of the mass movements

• 1983 Thistle Utah

• 1996 landslide Puget Sound

• La Conchita California 1995

mudflow

-thick mixture of sediments and water flowing down a slope

B.

• A mudflow is the rapid movement of a mixture of rock/soil with a significant component of water or air.

soil and rock slip down slope in

slumpone large mass

C.

• A slump is a type of slope failure which involves the rotational movement of soil or rock

creep- slowdownhill movement of weathered material

D.

This is a diagram of creep. The hillside slowly slips over many years from

temperature or water.

5. Water cycle-

Each part of the cycle drives the other parts.

A.____________- water changing to water vaporevaporation

1) ____________________ - evaporation from ice;sublimation

2) __________ Evaporation from plants

transpiration

B. _ -changing water vapor into liquid form

condensation

C. ___________- liquid or solid form of water falling to Earth

precipitation

6.________-rainwater that does not soak into the ground or evaporate

runoff

groundwater7.___________water that sinks (leaches) into the porous parts of Earth’s crust (about 90% of all fresh water)

8. ________________- an underground area that has been eroded by _____________________ (carbonation)

cave or cavern

chemical weathering

9._____________- “V” icicle-like structures formed by calcium carbonate left behind from dripping water

stalactite

10. _________ - “^ ” deposits of calcium carbonate that build up on the floor of a cave or cavern.

stalagmite

GLACIERGLACIERSS

glacier-

a thick river of ice that moves slowly across land

11. _______

A.________-plucking

rocks freeze in cracks under theice and are dragged along

abrasion

scouring of bedrock by imbedded rocks

B. ___________

scratches made on the bedrock

by the imbedded rocks

striationsC. _________-

unsorted, mixture of different-sizedsediments left by a glacier

till12. __-

ridges of broken rock pieces left on the sides and at the end of a glacier

moraine13. ________-

mass coverage of land area (Ice Age, Antarctica)

continental glacier14. _______________-

valley glacier

ice flows from high altitudes down a mountain

15. _________-

A. They have carved out many geological features, like mountains and valleys.B. They deposited much of the sand and gravel that is used for construction purposes.

16. Importance of Glaciers

17. Erosion by Waves17. Erosion by WavesA. ___________- part of the coast that sticks out into the oceanB. ________- area of wave-washed sediment along the coast

headlandheadland

beachbeach

C. _______- beach that projects like a finger out into the waterD. __________________- sediment moves down the beach with the current

spit

longshore drift

18.

deflation-Removal of looseA.material from ground’s surface

scouring action of particles carried by the wind (like___________ )sand blasting

abrasion-B.

loess-

wind-blown deposits of ______fine

dust particle that often pack into layers; soft, like talc

A.

dunes- mounds of sand drifted

downwind

(most common wind deposit)

B.

by the wind, which migrate