1. The Ocean Floor
Chapter 14 pg 393

2. 71% of earth is covered by ocean Oceanography – study of the ocean
A. The Vast World Ocean
The blue planet
71% of earth is covered by ocean
Oceanography – study of the ocean
Geography of oceans
4 main ocean basins
Pacific Ocean
Largest ocean
Deepest ocean (average depth 2.45 miles)

3. 2) Atlantic a) Half the size as Pacific and not as deep b) East coast of USA 3) Indian Ocean a) Smaller than Atlantic b) Same average depth as Atlantic c) Sothern hemisphere

4. 4) Arctic Ocean a) 7% the size of Pacific b) 25% as deep as other oceans b. 5th ocean 1) Southern/Antarctic ocean 2) Historically not included c. 1 global ocean

6. 3. Mapping the Ocean Floor a
3. Mapping the Ocean Floor a. Topography – detailed mapping of areas features b. Will find – mountain ranges, trenches, plateaus, and volcanoes c. HMS Challenger – lowered long weighted cables

7. d. Today 1) SONAR a) Sound Navigation And Ranging b) Bounces sound waves off ocean floor c) Records time it takes to return
Multiple beam sonar – more than one sound source

8. 2) Satellites 3) Submersibles a) Small underwater craft used for deep sea research b) Varying technology: cameras, thermometers, pressure gauges, mechanical arms, etc. c) Can be manned or unmanned

9. B. Ocean floor features
Continental Margins
Transition zone b/w continents and the adjacent ocean floor
Continental Shelf
Gentle sloping surface extending from the shoreline
Contain important features
Mineral deposits
Oil and natural gas
Sand and gravel deposits

11. c. Continental Slope 1) Marks the boundary b/w continental and oceanic crust 2) Submarine canyons a) Deep, steep-sided valleys b) Made by turbidity currents – movements of dense, sediment-rich water down the continental slope

13. d. Continental Rise – continental slope merges into a more gradual incline

14. 2. Ocean basin floor a. Area between continental margin and mid-ocean ridge b. Deep-Ocean Trenches 1) Long, narrow creases in ocean floor 2) Cause deepest parts of ocean 3) Mariana Trench a) Deepest known place on earth b) 11,022 meters (6.8 miles)

15. 4) Occur at subduction zones 5) Have earthquakes and volcanoes

16. Mariana Trench
Deepest Place In The World

17. Animals of the Mariana Trench

19. c. Abyssal plains 1) Deep and extremely flat features 2) Sediments burry all other features by turbidity currents d. Seamounts – submerged volcanic peaks

21. 3. Mid-ocean ridges a. Near center of most ocean basins b
3. Mid-ocean ridges a. Near center of most ocean basins b. Longest topographical feature on earth c. Seafloor spreading 1) Happens at divergent plate boundaries 2) Forms new ocean floor with rising magma d. Hydrothermal vents 1) Causes mineral-rich, heated water 2) Hits cold water and S, Fe, Cu, and Zn precipitate out

22. Hydrothermal Vents
Tube Worms

23. C. Seafloor sediments
Terrigenous – sediments originating from land
Biogenous – sediments with a biological origin
Calcareous ooze – produced from calcium carbonate in shells
Siliceous ooze – produced from diatoms
Hydrogenous – minerals that crystallize directly from ocean water by chemical reactions

24. D. Resources from the seafloor
Energy Resources
Oil and natural gas
Main energy source from ocean floor
Remains of animal remains
Concerns with oil spills

25. 2010 Bp oil spill

27. b. Gas Hydrates 1) Compact chemical structures 2) Typically form when bacteria break down organic material

28. 2. Other Resources a. Sand and Gravel 1) 2nd in economic value to petroleum industry 2) Used for landfills and concrete 3) Some places contain titanium, gold, or diamond deposits

29. b. Manganese Nodules 1) Lumps of manganese and other metals 2) Fairly wide spread 3) Environmental concerns with mining

30. c. Evaporative salts 1) Salt precipitates out of water 2) Gives halite (table salt) 3) Used for seasoning, preserving, agriculture, and clothing industry