1. The Sea Floor

2. Q: Of the Norhern and Southern Hemisphere, which one contains the most water??Q: Of the Norhern and Southern Hemisphere, which one contains the most water?? A: Right! The Southern Hemisphere contains nearly 80% water by volume.A: Right! The Southern Hemisphere contains nearly 80% water by volume. Q: Which ocean is the largest? The deepest?Q: Which ocean is the largest? The deepest? a. Arctic b. Pacific c. Atlantic d. Indian A: PacificA: Pacific A: Pacific again!A: Pacific again! Brain Warmers:

3. Figure 2.02

5. Big bang leftovers!Big bang leftovers! Density played a major role.Density played a major role. How’s that work??How’s that work?? Density = mass/volumeDensity = mass/volume Lighter stuff stays on the top!Lighter stuff stays on the top! How did it all get this way?

6. Figure 2.03

7. Ocean crust is composed of basalt. Basalt is common to the sea floor also.Ocean crust is composed of basalt. Basalt is common to the sea floor also. Much of the crust which forms land masses is composed of granite.Much of the crust which forms land masses is composed of granite. Much of the ocean floor and crust differs in age too! (200 myo compared to 3.8 byo!!)Much of the ocean floor and crust differs in age too! (200 myo compared to 3.8 byo!!) Why??Why?? Ocean Floor Facts

8. Sir Francis Bacon (1620) considered contents puzzle pieces.Sir Francis Bacon (1620) considered contents puzzle pieces. Geological features (coal deposits) matched on opposite coasts.Geological features (coal deposits) matched on opposite coasts. Ocean Floor Structure

9. Figure 2.04

10. Sir Francis Bacon (1620) considered contents puzzle pieces.Sir Francis Bacon (1620) considered contents puzzle pieces. Geological features (coal deposits) matched on opposite coasts.Geological features (coal deposits) matched on opposite coasts. Alfred Wegner (1912) hypothesized continental drift.Alfred Wegner (1912) hypothesized continental drift. Ocean Floor Structure

11. Continents may have been one piece which later broke appart, moved, and formed present day conditions.Continents may have been one piece which later broke appart, moved, and formed present day conditions. How??How?? Plate tectonics ocean floor movement.Plate tectonics ocean floor movement. Consists of faults (cracks) which form the mid ocean ridges (mountains).Consists of faults (cracks) which form the mid ocean ridges (mountains). Pangea Bound… 180 mya 150 mya 95 mya 45 mya 15 mya

12. Figure 2.05 Current Mid-ocean ridges & trenches

13. Figure 2.06 These locations are a significant source of geological activity!

14. Figure 2.07

15. Figure 2.08 Sea floor spreading occurs at mid-ocean ridges. mid-ocean ridges. Magnetic anomalies occur here too! Magnetic anomalies occur here too! “Okay, Dr. K. You’re using big words again!!” big words again!!”

16. Magnetic anemone!! But seriously….

17. Sea-floor spreadingSea-floor spreading where the ocean floor moves away from the mid-ocean ridge records the magnetic fields of the earth.

18. Figure 2.10 Locations and direction of seafloor spreading.

19. Figure 2.11 Crust and mantle come together to form the lithosphere. Subduction and resulting subduction zones where ocean floor plates flow beneath the mantle of the crust are places of tectonic activity. plates flow beneath the mantle of the crust are places of tectonic activity.

20. Figure 2.12 Trenches and island arcs can be formed when two sections of ocean plates come together.

21. Figure 2.13 Some areas can be quite acitve!! Mt. Veniaminof, Alaska

22. Figure 2.14 When plates move sideways then a new formation called a shear-boundary. San Andreas Fault, CA

23. Figure 2.15 Swirlling vs. Pulling Convection suggests that continents move on a “soup” of rock, Whearas slab pulling indicates that as rock cools, it sink beneath the surface and “pulls” lithosphere into the depths (This is the currently accepted explanation.)

24. Figure 2.17 Ocean sediments often preserve organism which help scientist age the ocean floor. Lithogenous sediment contains minerals, while biogenous sediment contains fossil remains.

25. Figure 2.19

26. Figure 2.20

27. Figure 2.21

28. Figure 2.22

29. Figure 2.23

30. Figure 2.24

31. Figure 2.25

32. Figure 2.26

33. Figure 2.27

34. Text Art 2.01

35. Text Art 2.02