Waves Section 9.5

Waves Waves form from wind that blows across the surface of the water Particles of water move in a circular pattern but the wave moves forward

As a wave moves near land, the bottom drags and the wave slows down As a wave moves near land, the bottom drags and the wave slows down. The water moves forward and provides the force that changes the shoreline

Erosion by waves Impact – waves hit rock and break them Abrasion – waves carry sediment that wears away other rock Headland – a part of the shore that changes the direction of waves

Landforms Sea cave – where waves erode softer rock at the base of land

Landforms Wave cut cliff – where rock collapses because the base was hollowed out

Landforms Sea arch – where waves erode softer rock under harder rock. If the arch collapses a sea stack could appear Sea Arch Sea Stack

Deposits Beaches – an area of wave washed sediment along a coast

Deposits Longshore Drift – waves, that hit the shore on an angle and run parallel to the shore, carry sediment down the beach

Deposits Spit – a beach that projects out into the water as a result of a longshore current

Deposits Sand Bar – long ridges of sand parallel to the shore

Deposits Barrier Beach – when waves pile sediment up above sea level

Wind Erosion Section 9.6

How Wind Causes Erosion Wind is the weakest agent of erosion It can be a powerful force in areas where there are few plants

How Wind Causes Erosion Deflation – the process by which wind removes surface materials. The stronger the wind, the larger the particle that can be moved

How Wind Causes Erosion Abrasion – wind carried sand can polish rock (sand blasting) but causes little erosion. Could have been caused by weathering or water erosion

Wind Deposition When wind slows down, sediment is deposited Sand dunes and loess deposits are formed by wind erosion and deposition

Sand Dunes Form when wind strikes an obstacle Found on beaches and in deserts where sediment has built up

Sand Dunes

Loess Deposits Fine sediment deposited far from its source Found in central part of U.S. Helps to form fertile soil

Loess Deposits