WindWind

Earth’s Changing SurfaceEarth’s Changing Surface

ReviewReview

5 Agents of Erosion5 Agents of Erosion GravityGravity Running WaterRunning Water GlaciersGlaciers Wind WavesWind Waves

Erosion by WindErosion by Wind

Wind by itself is the weakest agent Wind by itself is the weakest agent of erosion. of erosion.

Powerful force where there are few Powerful force where there are few plants to hold the soil in place. plants to hold the soil in place.

Wind ErosionWind Erosion

DeflationDeflation The process by which wind removes The process by which wind removes

surface material.surface material.

Abrasion Abrasion

AbrasionAbrasion Sand carried by wind can polish rocksSand carried by wind can polish rocks

Wind DepositionWind Deposition

Wind Erosion and Deposition form Wind Erosion and Deposition form sand dunes and loess deposits. sand dunes and loess deposits.

Sand dunes – A deposit of wind-Sand dunes – A deposit of wind-blown sandblown sand

Forms when the wind strikes an Forms when the wind strikes an obstacle. The sand then begins to obstacle. The sand then begins to pile up. pile up. Sand dunes move over timeSand dunes move over time

Sand DuneSand Dune

Sand Dune WorksheetSand Dune Worksheet

Loess DepositsLoess Deposits

Sediment that is finer than sand, Sediment that is finer than sand, such as particles of clay and silt, is such as particles of clay and silt, is sometimes deposited in layers far sometimes deposited in layers far from its source.from its source.

WavesWaves

Earth’s Changing SurfaceEarth’s Changing Surface

How are Waves formed?How are Waves formed?

The energy in waves comes from The energy in waves comes from wind that blows across the water’s wind that blows across the water’s surface. surface.

WavesWaves

Waves shape the coast through Waves shape the coast through erosion by breaking down rock and erosion by breaking down rock and transporting sand and other transporting sand and other sediment. sediment.

Erosion by WavesErosion by Waves

Impact – large waves can hit rocks. Impact – large waves can hit rocks. The energy in waves can break apart The energy in waves can break apart rocks. rocks.

Abrasion – sediment picked up by Abrasion – sediment picked up by waves wear away rock.waves wear away rock.

Waves changing direction – waves Waves changing direction – waves begin to drag on the bottom as they begin to drag on the bottom as they approach the shore.approach the shore.

Deposits by WavesDeposits by Waves

Waves shape a coast when they Waves shape a coast when they deposit sediment, forming coastal deposit sediment, forming coastal features such as beaches, spits, and features such as beaches, spits, and barrier beaches. barrier beaches.

BeachesBeaches

As waves reach the shore, they drop As waves reach the shore, they drop the sediment they carry, forming a the sediment they carry, forming a beachbeach

A Beach is an area of wave-washed A Beach is an area of wave-washed sediment along a coast.sediment along a coast. Usually sand Usually sand Some are made of small fragments of Some are made of small fragments of

coral or sea shells, Florida coral or sea shells, Florida

Beach in Southern Beach in Southern CaliforniaCalifornia

Lake Superior BeachLake Superior Beach

Florida Keys BeachFlorida Keys Beach