The Oceans

1. The Oceans

2. Essential Points • The ocean is salty because erosion brings dissolved elements to the sea • The Coriolis Effect causes ocean currents to travel curving paths • Surface currents in the ocean are driven by the winds • Vertical movements in the ocean are due to density differences

3. Element Weight %: 1%=10 gm/liter Cl 1.9 Na 1.05 Mg 0.135 S 0.0885 Ca 0.040 K 0.038 Br 0.0065 C 0.0028 Sr 0.00081 B 0..00096 Si 0.00030 F 0.00013 Composition of Sea Water 1. The ocean is salty because erosion brings dissolved elements to the sea

4. Residence Times Amount in Ocean/Rate of Addition Al – 150 years • Very Insoluble Si – 60,000 years • Used by marine organisms Ca – 8 million years • Used by marine organisms 1. The ocean is salty because erosion brings dissolved elements to the sea

5. Why the Ocean is Salty • Ca is 2.5 times as abundant in river water as Na • Ca is used by marine organisms • Na and Cl have residence times > 100 million years 1. The ocean is salty because erosion brings dissolved elements to the sea

6. Rotation Effects 2. The Coriolis Effect causes ocean currents to travel curving paths

7. The Coriolis Effect • Due to moving on a rotating earth • Things on equator are moving faster than points near poles • Affects: • Winds • Ocean Currents • Tides 2. The Coriolis Effect causes ocean currents to travel curving paths

8. The Coriolis Effect • Things moving toward the equator are deflected west • Things moving poleward are deflected east • Deflected to Right in Northern Hemisphere • Deflected to left in Southern Hemisphere 2. The Coriolis Effect causes ocean currents to travel curving paths

9. Not a Manifestation of the Coriolis Effect! • Too small scale for the Coriolis Effect to be significant

10. Ocean Currents 3. Surface currents in the ocean are driven by the winds

11. Tracking Ocean Currents

12. The Global Heat Conveyor 4. Vertical movements in the ocean are due to density differences

13. Essential Points • The ocean is salty because erosion brings dissolved elements to the sea • The Coriolis Effect causes ocean currents to travel curving paths • Surface currents in the ocean are driven by the winds • Vertical movements in the ocean are due to density differences

14. Tides

15. Essential Points • Tides in the ocean are caused by both the Sun and Moon • Tides occur because the Sun and Moon pull stronger on one side of the earth than the other • There are two tidal bulges on opposite sides of the Earth • Solar and Lunar tidal effects can reinforce or weaken each other • Actual tide motions in the oceans are very complex • Tides are gradually slowing the earth’s rotation

16. There are Two Tidal Bulges 3. There are two tidal bulges on opposite sides of the Earth

17. Both Moon and Sun Cause Tides 4. Solar and Lunar tidal effects can reinforce or weaken each other

18. Tides and the Boston Tea Party, December 16, 1773 • Near Earth's perihelion: strong solar tides • Near lunar perigee: strong lunar tides • Full moon on December 13: spring tide • Overall effect: unusually large tidal range 4. Solar and Lunar tidal effects can reinforce or weaken each other

19. The Boston Tea Party, December 16, 1773 4. Solar and Lunar tidal effects can reinforce or weaken each other

20. Tides and the Battle of Tarawa, November 20, 1943 • Near Earth's perihelion: strong solar tides • Near lunar apogee: weak lunar tides • Near last-quarter moon: neap tide • Overall effect: unusually small tidal range 4. Solar and Lunar tidal effects can reinforce or weaken each other

21. Location of Tarawa 4. Solar and Lunar tidal effects can reinforce or weaken each other

22. The Attack on Tarawa 4. Solar and Lunar tidal effects can reinforce or weaken each other

23. Tarawa: What the Planners Wanted 4. Solar and Lunar tidal effects can reinforce or weaken each other

24. What Actually Happened 1027 Marines killed, 2292 wounded 4. Solar and Lunar tidal effects can reinforce or weaken each other

25. Tides and the Real Oceans 5. Actual tide motions in the oceans are very complex

26. The Gulf of St. Lawrence 5. Actual tide motions in the oceans are very complex

27. The Gulf of St. Lawrence 5. Actual tide motions in the oceans are very complex

28. How Tides Move in the Oceans 5. Actual tide motions in the oceans are very complex

29. Tides on the Real Earth 5. Actual tide motions in the oceans are very complex

30. Diurnal, Mixed and Semidiurnal Tides 5. Actual tide motions in the oceans are very complex

31. Global Tide Types 5. Actual tide motions in the oceans are very complex

32. Global Tide Heights 5. Actual tide motions in the oceans are very complex

33. Tides in Confined Spaces 5. Actual tide motions in the oceans are very complex

34. Tides in Confined Spaces 5. Actual tide motions in the oceans are very complex

35. Tides Affect Earth's Rotation 6. Tides are gradually slowing the earth’s rotation

36. Essential Points • Tides in the ocean are caused by both the Sun and Moon • Tides occur because the Sun and Moon pull stronger on one side of the earth than the other • There are two tidal bulges on opposite sides of the Earth • Solar and Lunar tidal effects can reinforce or weaken each other • Actual tide motions in the oceans are very complex • Tides are gradually slowing the earth’s rotation