Waves and Wind

1. Waves and Wind Chapter 3 Section 3

2. 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.

3. Anticipatory Set

4. Vocabulary • Headland • Beach • Longshoredrift • Spit • Sand dune

5. Deflation • loess

6. 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

7. 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

8. 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

10. 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

11. 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.

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

13. 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.

14. 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.

15. 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?

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