1 / 20

Wave Action

Wave Action. Wave Action . Wave: the movement of energy through a body of water Waves are formed when the wind blows across the water’s surface and transfers its energy to the water. Ocean Waves. Waves occur on the Lake Superior, too!. Wave Size. Wave size depends on three things:

derickc
Download Presentation

Wave Action

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wave Action

  2. Wave Action • Wave: the movement of energy through a body of water • Waves are formed when the wind blows across the water’s surface and transfers its energy to the water.

  3. Ocean Waves

  4. Waves occur on the Lake Superior, too!

  5. Wave Size • Wave size depends on three things: * Strength of the wind * Length of time that the wind blows * Distance the wind travels

  6. Wave Energy • The energy of the wave can be moved from the middle of the ocean to the shore, but the water molecules will not end up at the shore. • The energy transfers, the water molecules remain the same.

  7. Water Molecule motion during a wave • Water particles move in a circular pattern in the upper portions of the water. • The deeper you get, the less the circular motion. • Eventually you get deep enough that the circular motion stops. • This is why sunken treasure never moves

  8. Water motion

  9. Wave Characteristics • Crest – top of the wave • Trough – bottom of the wave • Wave Height – from the bottom of the trough to the top of the crest (just like your height) • Wave Length – horizontal distance between crests

  10. How do Waves Change near the Shore? • Breakers – white capped waves that crash onto the shore * In deep water -> waves travel as long, low waves called swells. * In shallow water near the shore -> wave height increases, wavelength decreases and breakers are created.

  11. Tsunamis • Tsunamis are waves caused by an earthquake beneath the ocean floor * Most common in the Pacific Ocean. * Alaska, Hawaii and the Pacific Northwest (Oregon and Washington) are the United States’ main concerns * December 26, 2004 – Indian Ocean tsunami that killed over 200,000 people

  12. Tsunami

  13. tsunami demo

  14. How do waves affect the shore? • Longshore Drift (Longshore current) • Waves come into the shore at an angle, not straight into the shore • When the wave goes back out, it pulls sediments with it. • Waves go back in again, but the sediments are moved slightly down the beach • Moves sediment slowly but constantly down the beach.

  15. Rip Currents • Rip Currents are a rush of water that flows rapidly back to sea through a narrow opening • They can be very dangerous, but narrow • If you find yourself caught in one, you should swim parallel to the shore to avoid the current, then swim inland.

  16. Escape a Rip Current

  17. Waves Causing Beach Erosion • Every minute of every day, the waves are constantly eroding the beaches. They move sediments from one place to the other. It becomes even worse when a storm is present. • Local beaches have to compensate for the removal of sand by off shore dredging. • How do the beach communities pay for this replacement process?

  18. Examples of Beach Erosion

  19. Erosion after Hurricanes

  20. Questions – Section 13-1 • How do waves form? • Why does an ocean buoy bob up and down in the ocean? • How do wavelength and wave height change as a wave enters shallow water? • Using what you know about wave height and wave length of tsunamis, propose and explanation of why tsunamis can cause so much damage when they reach the shore.

More Related