1. Lecture 5 Waves and Currents

2. Formation of Waves

3. Travelling Waves

4. Anatomy of Waves

5. Forces Generating Waves are Different Wave typePeriodDisturbing forceRestoring force Capillary<0.1 secWindSurface tension

6. Forces Generating Waves are Different Wave typePeriodDisturbing forceRestoring force Chop1 – 10 secWindGravity

7. Forces Generating Waves are Different Wave typePeriodDisturbing forceRestoring force Swell10 – 30 secWindGravity

8. Forces Generating Waves are Different Wave typePeriodDisturbing forceRestoring force Seiche10 min – 10 hrWind/SeismicGravity (standing wave)

9. Seiche waves

10. Forces Generating Waves are Different - Summary Wave typePeriodDisturbing forceRestoring force Capillary<0.1 secWindSurface tension Chop1 – 10 secWindGravity Swell10 – 30 secWindGravity Seiche10 min – 10 hrWind/SeismicGravity (standing wave) Tsunami10 min – 2 hrSeismicGravity Tide12.4 or 24.8 hrGravityGravity

11. Tsunamis http://www.youtube.com/watch?v=PBZGH3yieLc&lr=1&feature=mhum

13. Transition of one wave to another

14. Worldwide distribution of wave heights

15. Waves and Depth Deep water Shallow water

16. Breaking Waves

17. Types of Breaking Waves Spilling Result from waves of low steepness (long period swell) over gentle slopes.

18. Types of Breaking Waves Plunging Result from steeper waves over moderate slopes.

19. Types of Breaking Waves Surging Surging breakers surge over steeply sloping (but not vertical) beaches or rocks. Occur where the beach slope exceeds wave steepness.

20. Gentle – spilling Moderate – plunging Steep - surging Wave breaking

21. Refraction of Waves

24. Currents

25. Currents - Rip currents

27. Currents - Coriolis Forces

28. Currents - Open Ocean

29. Ekman Spiral

30. Coastal Upwelling

32. Coastal Upwelling - Phytoplankton

33. Coastal Upwelling - Temperature

34. Coastal Upwelling - Fishing Upwelling areaFishing 0.1% 50%

35. Langmuir Cells

37. Langmuir cells in sea ice

38. Deep Ocean Currents Animation

39. Next time: Coastlines