2. Oceanography
Ocean Floor Features
Ocean Circulation
Waves and Tides

3. Oceans

4. Ocean Topography

5. How do we get the information about the ocean floor?
Sonar – Boats using sonar to map the ocean floor as they pass over it.
Boats have to go in set patterns going back and forth just like you would mow a lawn to make sure it covers everything
Slow process
Satellites
Measure the ocean surface height as small as 3-6cm
These can be affected by features under the water, help to verify sonar readings
Submersibles
Small underwater craft that can be manned or unmanned.
Give a visual as well as other readings to verify the findings in detail

6. Sonar

7. Starting at the beach
The area where a continental plate meets an oceanic plate is called a Continental Margin.
Most ocean features will be in this range due to plate tectonics

8. Beach to water Continental Shelf Gently sloped underwater surface
Some areas it is very short in width (convergent boundaries) while others can be quite large
Fairly flat, only dropping at about 2 meters per KM (6 feet per mile)
Great source of minerals, oil, natural gas, sand, gravel, and fishing

10. Continental Slope
The edge of the continental crust where it goes down to the oceanic crust
Much steeper where the water gets deep quickly
Can contain deep cuts called Submarine Canyons that can be ends of ancient rivers
They can also be formed from Turbidity Currents that have a lot of sediment moving at once
Because it is more muddy than normal seawater it is more dense and flows down the side eroding it

12. Continental Rise
Slope becomes much smaller as the ocean floor starts to flatten
No trenches in this area
Continental Slope leading down can be nearly 20km wide but the rise can be 100’s of km wide

14. Ocean Basin Floor 30% of Earth’s surface is ocean floor Abyssal Plains
Very deep very flat areas after the continental rise
Probably the flattest places on earth due to lots of sediment settling there at a fairly even rate
Mid-Ocean Ridges
Occur all around the Earth due to seafloor spreading
Divergent oceanic plates allow magma to come up and form ridges and create new ocean floor

15. Ocean Topography