1. Chapter 23
The Ocean Basins

2. Formation of the Oceans videoclip: http://www. bbc. co
During early years of Earth’s formation, volcanic activity added water vapor to atmosphere.
As earth and it’s atmosphere cooled, water condensed into rain. It rained for a very long time-filled the ocean basins
Comets also brought water from space

3. The Global Ocean Body of salt water
Covers nearly ¾ of the Earth’s surface
5 major oceans (from largest to smallest):
Pacific (also the deepest)
Atlantic
Indian
Southern
Arctic Ocean

4. What is the difference between the ocean and a sea?
Seas are smaller than oceans
May be partially surrounded by land
Major seas include:
Mediterranean
Caribbean
South China

5. Exploration Oceanography is the study of the ocean
Sonar is used to determine depths
This information is used to make maps and profiles of the ocean floor
Submersibles or subs allow oceanographers to study the ocean for extended times
Brain POP: Oceans

6. Brain POP: Ocean Floor 2 major areas of the ocean floor:
2 major areas of the ocean floor:
Continental margins
Deep ocean basins

7. Ocean Floor Features
Continental margins-shallow, continental crust with a thick wedge of sediment:
Continental shelf: part of continent covered by water
Continental slope and rise: see picture, pg. 642

8. Ocean Floor Features
Deep-ocean basins-oceanic crust and thin layer of sediment
Trenches: long narrow depressions in the deep ocean, caused by subduction
Abyssal plains: vast, flat areas in water over 4 km deep
Mid-Ocean ridges: caused by divergent boundaries, underwater mountain ranges, site of sea floor spreading
Seamounts: submerged volcanic mountains taller than 1 km

10. Ocean Floor Sediments Carried into oceans by rivers or streams
How do sediments get deposited into the ocean?
Carried into oceans by rivers or streams
Carried into ocean by wave erosion
Organisms die-remains settle on ocean floor

11. Ocean Floor Sediments Inorganic: rock particles
Biogenic: produced by living things-diatoms (Protists)
Chemical: substances dissolved in water crystallize

12. Biogenic Sediments-produced by living things:
Common compound: silica (SiO2) and Calcium Carbonate (CaCO3)
Foraminiferans
Diatoms

13. Nodules
Inorganic mineral deposits formed when minerals dissolved in water crystallize into solids on ocean floor

14. Deep ocean floor sediments
Muds: very fine silt/clay
Oozes: soft, fine sediment, 2 types: calcareous and siliceous