1. What I will learn…
(3-1) Describe how technologies help scientists map the ocean floor
(3-2) Identify the following features on a sea floor map: continental shelf, continental slope, continental rise, trenches, plains, sea mounts, guyots, and mid-ocean ridges.

2. Think About It
At its deepest point, the Puerto Rico Trench in the Atlantic Ocean is 28,231 feet (more than 5 miles deep). Because of the tremendous pressure, it is not possible for humans to personally explore this deep into the ocean.

3. Key Question
How do scientists know what the bottom of the ocean floor looks like? How do they know how deep the oceans are?
I think… because…

4. Investigating the Oceans
Earth = Blue Planet
71% of planet covered with water
97% of that water is found in oceans
Oceanography = Study of planet’s oceans

5. Ocean Geography Four major ocean basins Atlantic
Pacific – largest and deepest
Indian
Arctic – smallest and most shallow

7. Tools for measuring the depth of the ocean floor
Sonar
Satellites
Submersibles

8. Sonar = Sound Navigation and Ranging
Sound waves sent to bottom of ocean
Sound waves reflected back to a receiver
Based on time it takes for wave to be reflected, the distance to ocean floor can be measured

9. Satellites
Can measure the differences in the sea-surface height by bouncing microwaves off the ocean’s surface
Underwater mountains cause sea surface level to be higher
Canyons & trenches
cause sea surface
to be lower

10. Submersibles Underwater vessel that can be used for deep sea research
Can be manned or unmanned (ROV)
Carry scientific instruments to learn about ocean

11. The ocean floor is NOT flat!
3 Major Regions
Continental Margins
Ocean Basin Floor
Mid-Ocean Ridge

12. A=Continental Shelf= Gently sloping area that extends from the shoreline

13. B=Continental Slope= Steep slope that marks boundary between continental crust and oceanic crust

14. C=Deep-Ocean Trench= Deepest part of the ocean; form when one plate moves underneath another plate

15. D=Mid-Ocean Ridge= Underwater mountain system; sea floor spreads apart; formed new ocean crust

16. E=Volcanic Island= Seamount that reaches the surface of the ocean

17. F=Seamount= Underwater volcano

18. G=Abyssal Plain= flat feature on bottom of ocean floor; most level places on Earth

20. Cape May, NJ
Cape Roca, Portugal

21. Investigate Part B: Mapping the Ocean Floor
Distance
Depth

22. Direction #5 Color the ocean crust (sea floor) brown
Color the water areas (not the ocean floor) on your graph:
Depth between light green
Depth between light blue
Depth between 1100 – ocean floor dark blue

23. Cape Roca, Portugal
Cape Roca, Portugal
Azores, Portugal
Azores, Portugal
Azores, Portugal
Azores, Portugal
Cape May, NJ
Cape May, NJ
Cape May, NJ
Cape May, NJ
Mid Atlantic Ridge
Mid Atlantic Ridge
Mid Atlantic Ridge

24. Continental Shelf Continental Shelf Continental Shelf
Gently sloping area that extends from the shoreline
Continental Shelf
Gently sloping area that extends from the shoreline
Continental Shelf
Gently sloping area that extends from the shoreline
Continental Shelf
Gently sloping area that extends from the shoreline
Abyssal Plain
Deep extremely flat features
Abyssal Plain
Deep extremely flat features
Abyssal Plain
Deep extremely flat features
Continental Slope
Steep slope that marks boundary between continental crust and oceanic crust
Continental Slope
Steep slope that marks boundary between continental crust and oceanic crust
Continental Slope
Steep slope that marks boundary between continental crust and oceanic crust
Continental Slope
Steep slope that marks boundary between continental crust and oceanic crust
Seamount
Underwater volcanic peaks
Seamount
Underwater volcanic peaks

25. Azores, Portugal
Cape May, NJ
Cape Roca, Portugal
Mid Atlantic Ridge

26. Continental Shelf Continental Slope Seamount
Gently sloping area that extends from the shoreline
Continental Slope
Steep slope that marks boundary between continental crust and oceanic crust
Seamount
Underwater volcanic peaks