Agents of Erosion Notes

Erosion Caused by…Running Water

Erosion is…The process by which soil & sediment are transported from one location to another.The running water of the Colorado River cut down into the rock and formed the Grand Canyon over millions of years.

Flood Control (Levee)

Overflow from rivers/streams (running water) can be controlled by a barrier called a _____________. It is the buildup of sediment deposited along the channel of a river. People often use sandbags to build an artificial levee to control serious flooding.

Levee

Deposition in Water (Delta)Deposition is…The process in which material is laid down or dropped.When a river empties into a large body of water, like a lake or an ocean, the current slows. The river often deposits its load of sediments in a fan-shaped pattern called a ________. It is made mostly of ___________.

delta

mud

Deposition on LAND (Alluvial Fan)

When a fast moving mountain stream flows onto a flat plain, the stream slows down and deposits sediment. The sediment forms an ____________________. They form on __________ whereas deltas form in the mouth of a _________ or ____________.

Alluvial fanDry land

streamriver

Erosion Caused by WAVESWhen ________ crash into rocks over long periods of time, the rocks are broken down into smaller and smaller pieces until they become sand.Waves play a major role in building up (constructive) and breaking down (destructive) the _____________________.

waves

shoreline

Erosion Caused by WAVESWinds that result from _____________ and ____________________ produce large waves that cause dramatic shoreline erosion. A tremendous amount of ____________ is released when waves break. A crashing wave can break solid rock and throw broken rocks back against the shore. As a result of these actions, rock is broken down into smaller pieces that eventually become ______________.

hurricanesSevere storms

energy

sand

Erosion Caused by WAVES

Some coastal landforms created by wave erosion are:• Sea stacks• Sea arches• Sea caves• Headlands• Wave-cut terraces

WIND ErosionWind causes sand-sized particles to bounce and move the sand grains into one another. The skipping and bouncing movement of sand-sized particles in the direction the wind is blowing is called _____________.Wind can deposit extremely fine material. Thick deposits of this sediment are called _________. The wind can carry this fine material long distances from its source.

saltation

loess

WIND ErosionWhen wind hits obstacles, like _________, or rocks, the wind slows down. This slows down erosion. These obstacles cause heavier material (like sand) to be deposited (constructive) forming a _____________. These mounds of wind-deposited sand are called _____________.

plants

mound

dunes

ICE & GLACIER ErosionA ___________ is an enormous mass of moving ice. They form in areas that are so cold that snow stays on the ground year-round. Because glaciers are so massive, ____________ causes them to flow slowly.

glacier

gravity

ICE & GLACIER ErosionA ___________ glacier (a type of alpine glacier) forms in valleys in mountainous areas created by ________ erosion. They flow downhill and widen and straighten the valleys into _____ shapes from the original ______ shapes.

valley

stream

U

V

ICE & GLACIER Erosion

Continental glaciers are huge continuous masses of ________. The largest continental glacier in the world covers almost all of __________________. These glaciers ___________ the landscape by scraping and eroding features that were around before the ice appeared. They can flatten mountains.

Ice

Antarcticasmooth

Erosion caused by GRAVITY

Movement of water and ice is affected by __________, and it also causes rocks and soil to move downslope.Sometimes gravity causes rapid mass movement of rock that can be the most ________________ and very dangerous.

gravity

destructive

Erosion caused by GRAVITYA __________ happens when loose rocks fall down a steep slope.A __________ is the sudden and rapid movement of a large amount of material downslope.A ________ is the most common type of landslide. This happens when a block of material moves downslope over a ____________ surface.

Rock-fall

landslide

slump

curved

Erosion caused by GravityA ______________ is a rapid movement of a large mass of mud. This happens when a large amount of water mixes with soil and rock. Mudflows (destructive) can carry trees, houses, and cars.Slow mass movement occurs more ____________ than rapid mass movements. An example of slow mass movement is _________. Plants and animals can loosen rocks and soil and cause the rocks/soil to slowly travel downhill.

mudflow

frequently

creep