Ocean Currents and Waves

1. Ocean Currents and Waves http://www.oceanweather.com/data/

2. #9 Notes and Handouts Foldable:

3. Classwork #3Current Demo

4. #10 Notes and Handouts Foldable

5. Equatorial Equatorial Countercurrent

6. Southern Hemisphere • Antartic Circumpolar Current (a.k.a. West Wind Drift) = Largest current • Monsoons

7. North Atlantic • Gulf Stream-def. • North Atlantic Current Splits into… 1. Norway Current 2. Canary Current • Labrador Current

8. On Back- N. Atlantic • North Atlantic Gyre • Sargasso Sea • Sargassum

9. North Pacific • Kurshio Current • The “Gulf Stream” for Pacific Ocean • North Pacific Drift • California Drift

10. #11 Notes and Handouts Foldable

11. Antarctic Bottom Water • Densest and Coldest Ocean Water: • Extremely Cold (-2° C) • High Salinity • Moves N-ward along the bottom to ~40°N • Takes 100’s of years to make the trip

12. North Atlantic Deep Water • Moves Southward under the Gulf Stream • Deep Currents near Mediterranean Sea • High Salinity in Mediterranean Sea caused by high evaporation and low precipitation ON BACK: Turbidity Currents -Strong current cause by underwater landslide

13. Ch 21 Sec 2Ocean Waves

14. #12 Notes and Handouts Foldable

15. Wave Parts

16. On Back- Definitions • Wave – A periodic disturbance in a solid, liquid or gas as E is transmitted through a medium • Wave period – Time for two consecutive wave crests to pass a given point • Frequency – # of wavelengths that pass in 1 second • Wave speed Wave speed = Wavelength/Wave Period

17. Ocean Motion http://www.classzone.com/books/earth_science/terc/content/visualizations/es1604/es1604page01.cfm?chapter_no=visualization

18. # 13 Notes and Handouts Foldable

19. Inside the Foldable- • 3 Factors that affect wave size- • Speed of Wind • Length of Time Wind Blows • Fetch- the distance that wind can blow across open water • Increase factor  Increase Wave Size

20. Small- (Back of Flap) • Ripples • Caused by friction between moving air and water

21. Large- (Back of Flap) • Form as a ripple • Receive more Energy (E) from the Wind Higher Speed  Larger E transmit.  Larger Wave ↑ Time blowing  Larger E transmit.  Larger Wave ↑ Fetch  Larger E transmit.  Larger Wave

22. On Back DEFINE: • Swell – Group of long, rolling waves that are of similar size; move in groups in which one wave follows another • White Caps – Form when wind blows the crest off of waves; reflect the sun and allow less radiation to reach the ocean

23. #14 Notes and Handout Foldable

24. Breakers • A foamy mass of water that washes onto the coastline. • Formed when top of the waves topples over. • Height = 1 to 2x larger than original wave • Scrape sediments off floor and move along coastline. • Erode rocky coastlines.

25. Refraction • Process by which ocean waves bend toward the coastline as they approach shallow water. • Point in shallow – slow • Point in deep – fast

26. Undertows vs. Rip Currents • Undertows – an irregular current formed when breaking waves get pulled back into deep water by gravity. • Rip Currents – form when water from large breakers return to ocean through channels cut through underwater sandbars.

27. Longshore Current • Form when waves approach the beach at angle. Flow parallel to shore. • Makes sandbars. • Sandbars – Low ridges of sand

28. On Back • Tsunami • Aka “Tidal Wave” but it is NOT caused by tides

29. #15 Notes and Handouts Foldable http://www.seas.upenn.edu/~electric/greenenergy3.htm

30. On Back • Tide – periodic rise and fall of water level in ocean due to gravitational pull of moon on earth. • Tidal Range – diff in levels of ocean water @ high and low tide.

31. High • When water level at highest. • Ocean on side of Earth nearest moon bulges as does the opposite side

32. Low • Lowest when water leaves. • Form halfway between 2 high tides.

33. Spring • Higher high tides and lower low tides during a new moon or a full moon • Moon, Sun, and earth line up • High Tidal Range

34. Neap • Lower high tides and higher low tides during the 1st and 3rd qtr phases of moon when S E and M. • Low Tide Range

35. #16 Notes and Handouts Foldable

36. On Back • Tidal Oscillations – slow, rocking motions of ocean water formed as the tidal bulges move around ocean basins.

37. Little Effect • Straight Coastlines

38. Greater Effect • Enclosed seas • Reduces effects of tidal bulges • Small tidal range • Small basins and narrow bays • Increase effects of tidal bulges • Large tidal range

39. #17 Notes and Handouts • Foldable

40. On Back • Tidal Current – Movement of water towards or away from the coast. • Tidal Bore – A surge of water that rushes upstream

41. Flood Tide • When the tidal current flows towards the coast.

42. Slack Water • The time between flood tide and ebb tide, where there are no tidal currents.

43. Ebb Tide • When the tide flows towards the ocean. http://www.answers.com/topic/tide