1. Features of the Ocean Floor
Handout 19-2
Features of the Ocean Floor

2. 1. The shallow sea floor between the shoreline and the deep-ocean bottom is called the
a. continental margin.

3. 2. Continental margins are made up of continental crust
b. and a thick wedge of sediment.

4. 3. The part of the continent covered by water is called the
c. continental shelf.

5. 4. The continental shelf slopes gently from the shoreline, and drops about 0.12 m every
b. 100 m.

6. 5. the average depth of the water covering a continental shelf is about
b. 60 m.

7. 6. The continental shelf is part of the
a. continental margin.

8. 7. V-shaped valleys in the continental shelf and continental slope are called ___________.
submarine canyons

9. 8. What is one place submarine canyons are often found?
Near the mouth of major rivers.

10. 9. How can turbidity currents help form submarine canyons?
Turbidity currents carry sediment down the continental slopes.

11. 10. How do turbidity currents form?
When earthquakes cause underwater landslides
When large sediment loads run down a slope

12. 11. What is the name of the deepest place in Earth’s crust?
The Mariana Trench

13. 12. Where is the deepest place in Earth’s crust located?
The Western Pacific Ocean

14. 13. About how deep is the deepest place in Earth’s crust?
More than 11,000 meters deep
36,089 ft.
6.8 miles

15. 14. In the deep-ocean basins, what is a trench?
A long, narrow and steep depression that forms on the oceanfloor.

16. 15. How do trenches form in the deep-ocean basins?
Trenches form in deep ocean basins as a result of subduction of a tectonic plate.

17. 16. About half of the deep-ocean basins are covered by _______­­­­­___.
Abyssal plains

18. 17. The flattest regions on Earth are ____________
 Abyssal plains

19. 18. Layers of fine _________ cover the abyssal plains.
sediment

20. 19. How does the age of the oceanic crust affect the thickness of sediments on the abyssal plains?
Older crust is generally covered with thicker sediments than younger.

21. 20. The most prominent features of ocean basins are _________.
 mid-ocean ridges.

22. 21. Mid-ocean ridges form underwater ________.
mountain ranges.

23. 22. What is one place where a mid-ocean ridge rises above sea level?
Iceland

24. 23. Where do seamounts form?
Near hotspots
Areas of increased volcanic activity

25. a. an area of increased volcanic activity where seamounts form b
a. an area of increased volcanic activity where seamounts form b. submerged seamount with a flat top c. a seamount that rises above the ocean d. an oceanic island that is in the process of being eroded into a guyot e. submerged volcanic mountain taller than 1 km
24. guyot
25. hot spot
26. seamount
27. atoll
28. oceanic island

26. The End!!!