Waves and Wind Chapter 3 Section 3

Standard S 6.2 a Surface water flow, glaciers, wind and ocean waves have all been an continue to be active throughout California and the rest of the world in shaping landscapes. S6.2c Students know beaches are dynamic systems in which the sand is supplied by rivers and moved along the coast by the action of waves.

Anticipatory Set

Vocabulary Headland Beach Longshore drift Spit Sand dune

Deflation loess

Input The energy in waves comes from wind that blows across the water’s surface. The energy that water picks up from the wind, causes water particles to move up and down as the wave goes by. A wave changes as it approaches land. Deep water- wave only affects the water near the surface Shallow water- wave begins to drag on the bottom and it causes the wave to slow down

Erosion by Waves Waves shape the coast through erosion by breaking down rock and transporting sand and other sediment. Impact- large waves hit the rocks along the shore and break them part. Over time pieces of the rock fall off. Waves coming to shore change direction. Headland- part of the shore that sticks out into the ocean. Made up of harder rocks

When waves hit a steep, rocky coast they strike the area again and again. It will begin to erode and make a cut. Each time it strikes the cut is getting bigger and bigger. Eventually, waves erode the base of a cliff so much that the rock collapse. Wave- cut cliff= waves erode the soft rock along the base of a steep coast and the results is a new landform called a wave-cut cliff

Deposits by Waves Waves shape a coast when they deposit sediment, forming coastal features such as beaches, spits, sandbars, and barrier beaches. Beach- an area of wave washed sediment along a coast. Usually sand is left behind. Beaches are constantly changing- supply of sand and wave motion. Long shore drift- when waves hit the beach, the beach sediment moves down the beach with the current

Spits- a beach that projects like a finger out in the water. Barrier Beach- forms when storm waves pile up large amounts of sand above sea level forming a long, narrow island parallel to the coast. Silver Strand Beach in California is a great example of a barrier beach. Some people have built homes on barrier beaches.

A fast flowing river would mostly likely lift sand sized particles of sediment and carry them downstream

Erosion by Wind Sand dune- is a deposit of wind blown sand. Wind cause erosion by deflation and abrasion. Wind is the weakest agent of erosion In a desert, it is constantly changing. Deflation- the process by which wind removes surface materials The strong the wind, the larger the sand particles it can pick up.

Deposition by Wind Abrasion- wind carried sand can polish rocks, but it causes little erosion. Wind erosion and deposition may form sand dunes and loess deposits. Wind carrying sand grains deposits the sand when the wind slows down or hits an obstacle. Loess- fine, wind deposited sediment. Particles of clay and silt eroded and deposited by the wind. Mojave Desert’s desert pavement was created through the process known as deflation.

Checking for Understanding What are 2 kinds of wind erosion? How does an ocean wave change when it reaches shallow water? What are 2 ways in which waves cause erosion?

Guided Practice Independent Practice Guided Practice: Page 67 of Wave worksheet First, intrapersonally. Second, with a partner interpersonally. Independent Practice: Wave Worksheet