Chapter 21 Section 2 Chapter 21 Section 2 Review Page 530Review Page 530

Wave partsWave parts

1. Explain how 1. Explain how wavelength and wave wavelength and wave period can be used to period can be used to calculate wave speed.calculate wave speed.

• Wave speed = Wave speed = wavelengthwavelength

wave periodwave period

2. Describe the 2. Describe the formation of waves.formation of waves.

• Uneven heating of Earth creates Uneven heating of Earth creates winds. Waves form when friction winds. Waves form when friction between moving air and water between moving air and water causes ripples.causes ripples.

3. List three factors that 3. List three factors that determine the size of a determine the size of a wave.wave.

• Length of time the wind blows in Length of time the wind blows in one directionone direction

• The speed of the windThe speed of the wind

• The fetch (distance the wind can The fetch (distance the wind can blow across open water)blow across open water)

4. Explain why incoming 4. Explain why incoming waves refract (bend) waves refract (bend) toward the beach until toward the beach until they strike the shore they strike the shore head-on.head-on.

• Most waves approach the coast Most waves approach the coast at an angle. Friction with the at an angle. Friction with the bottom slows the part of the bottom slows the part of the wave that is in the shallower wave that is in the shallower water, while the part in the deep water, while the part in the deep water keeps moving fast. This water keeps moving fast. This causes the wave to bend causes the wave to bend gradually toward the shoreline.gradually toward the shoreline.

Wave “Bottoms out”Wave “Bottoms out”

Waves bending asWaves bending as they approach the they approach the shoreshore

5. Describe what factors 5. Describe what factors cause tsunamis.cause tsunamis.

• Tsunamis are caused by:Tsunamis are caused by:

• underwater earthquakesunderwater earthquakes

• Volcanic eruptionsVolcanic eruptions

• Underwater landslidesUnderwater landslides

6. Explain why waves slow 6. Explain why waves slow down in shallow water.down in shallow water.

• Contact with the ocean floor Contact with the ocean floor creates friction, which causes creates friction, which causes the wave to slow down.the wave to slow down.

7. Explain how whitecaps 7. Explain how whitecaps could affect climate.could affect climate.

• Whitecaps reflect solar energy, Whitecaps reflect solar energy, which allows less radiation to which allows less radiation to reach the ocean. If less thermal reach the ocean. If less thermal (heat) energy is transferred to (heat) energy is transferred to the water, then there is less heat the water, then there is less heat available in the water to available in the water to moderate climates along the moderate climates along the path of ocean currents.path of ocean currents.

The EndThe End