1 / 28

Chapter 7 Waves in the Ocean Words from these PPT slides are already on the course web site.

Chapter 7 Waves in the Ocean Words from these PPT slides are already on the course web site. Wave Parameters (Figure 7-1a). Properties of Ocean Waves. An ocean wave is an undulation of the sea surface. Wave crest Wave trough Wave height Wave length Wave period

ling
Download Presentation

Chapter 7 Waves in the Ocean Words from these PPT slides are already on the course web site.

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. Chapter 7Waves in the OceanWords from these PPT slides are already on the course web site.

  2. Wave Parameters(Figure 7-1a)

  3. Properties of Ocean Waves • An ocean wave is an undulation of the sea surface. • Wave crest • Wave trough • Wave height • Wave length • Wave period • Progressive wavesmove across the sea surface. • Standing wavesoscillate about a fixed point.

  4. What Causes Waves? • Wind • Submarine disturbance • Gravitational attraction of sun and moon

  5. Wind Generation of Waves • Wind velocity • Wind duration • Fetch (distance over which wind blows) • Simply put, wave size increases as all these factors increase.

  6. Progressive Waves • Wind-generated waves are progressive wavesbecause they travel across the sea surface.

  7. Progressive Wave Types • Sea - irregular waves in the area of generation • Swell - more regular waves beyond area of generation • Surf - waves that have reached the coast, grow in height, and break

  8. Wave Motions • Forward movement of the wave form. • Orbital motion of water particles beneath the wave. • It is wave energy,NOT water molecules, that moves across the sea surface.

  9. Flow of Energy,not Mass (Figure 7-2)

  10. Wave Motion with Depth(Figure 7-3a)

  11. Motion Animation

  12. Deep Water Waves(Figure 7-4a) Waves do NOT interact with the seafloor. Orbits of the water molecules are circular.

  13. Shallow Water Waves(Figure 7-4b) Waves DO interact with the seafloor. Orbits of the water molecules become elliptical.

  14. Life History of Ocean Waves(Figure 7-7a)

  15. Life History of Ocean Waves • Waves originate in the fetch area. This area is characterized by a “confused” sea state with extensive wave interference.This interference may be • Constructive • Destructive

  16. Rogue Waves?(Figure 7-6b) • Constructive wave interference - wave buildup

  17. Destructive Waves(Figure 7-6c) • Destructive wave interference - wave cancellation

  18. Progressive Wave Types • Sea - irregular waves in the area of generation • Swell - more regular waves beyond area of generation • Surf - waves that have reached the coast, grow in height, and break

  19. Transformation of Deep-water Waves:Dispersion(Figure 7-7a)

  20. Shallow Waves Affected by Bottom • In shallow water, the sea bottom transforms the wave’s properties. This leads to wave refractionand waves collapse forming surf(breakers).

  21. Wave Refraction(Figure 7-8a) • Bending of the wave crest as waves enter shallow water. It is due to • Drag along the bottom. • Differential speed along the crest.

  22. Shallow-water Wave Transformations • Interaction with the sea bottom. • Bottom friction alters both the • Wave form • Wavelength shortens (decreases) • Height increases • Celerity (speed of wave form) • decreases

  23. Transformation of Shallow-water Waves(Figure 7-7b)

  24. Progressive Wave Types Swell Sea Surf

  25. Surf’s Up! SpillingPlunging, orSurging • depending on the slope of the bottom (Figure 7-9)

  26. Condition Black Video

  27. Motion of Water Particles Beneath Waves(Figure 7-3b)

More Related