Florida Gateway College
Earth Science/ Dr. Kane
Chapter 13: The Ocean Floor
________________________________________________________________________
________________________________________________________________________
_________________________
1. Open this link: Earth Revealed series and watch the video #4 (The Sea
Floor)
2. Open this link:Episode 4: and answer the questions after watching the
video; turn it in for a 15% extra credit.
3. Go to the Key terms page below, print out the page and answer the questions
4. Print out the practice test page below and answer the questions
5. Bring the package with you on test day to get credit. Homework counts for
25% of your final grade.
Key Terms:
Please, research these keywords in your textbook, study guide, and other documents you may have.
Pay attention to the video, and take notes if you like, but you may not use them during the test. You
will have 4 or more extra credit questions count for 20% or more.
Click for more Ocean Videos
I - Ocean Salinity
1. Composition of seawater. Define ocean salinity
2. Variations of salinity, with latitude: explain
3. Variations of density with latitude: explain
4. Variation of temperature of seawater with latitude: explain
5. What causes ocean temperature variation? Explain
6. What causes ocean salinity variation? Explain
7. Thermocline: definition and cause
8. Pycnocline: definition and cause
9. Ocean layering: reason of layering, name the layers, and what are their
characteristics
10. Salts of the ocean: the most abundant salt is
11. Relationship between ocean temperature, salinity, and density. Explain
II - Ocean floor Topography
12. Name and define the major topographic units of the ocean floor
13. World Oceans (name, and distribution)
14. Structure and seafloor depth measurement: how was the seafloor topography
investigated?
15. The three major units of the seafloor topography are:
16. How does Pressure vary with the depth of the ocean?
17. Characteristics and types of continental margins
18. From continent to Ocean: Continental shelf/Continental slope/Continental rise/Abyssal
Plains
19. Mid ocean ridge (Its origin and importance in the seafloor formation)
20. Seamounts and Guyots (origin, and difference)
21. Deep Ocean trenches (definition and location)
22. Seafloor sediments (types, origin, distribution, and composition)
23. Calcareous ooze and siliceous ooze (definition, and origin)
24. Turbidity currents (Definition)
25. Submarine canyons (how do they form?)
26. Ocean floor rock (How does it form? What type of rock is it? How old is the ocean floor
rock?)
27. Hydrothermal vents (Where are they located? What roles (s) do they play?)
28. Manganese nodules (location, and economic importance)
29. Energy resources of the seafloor (What can we mine from the ocean floor?)
30. Is there any life form in the mid ocean ridge? If so, how does it survive?
______________________________________________________________________________________
___________________________________________________________________________________
PRACTICE TEST /Test 5
(Chapter 9: The Ocean floor)
Circle the correct answer
1.
Which one of the following is NOT part of a passive continental margin?
a.
b.
c.
d.
2.
Continental shelf
Continental slope
Continental rise
Continental trench
Which of the following is NOT true of deep ocean trenches?
a.
b.
c.
d.
They are long and narrow depressions at subduction zones
They are sites where plates plunge back into the mantle
They are associated with mid ocean ridges
They are part of active continental margins
3.
"Black smokers" are associated with.
a.
b.
c.
d.
e.
4.
The gently sloping submerged surface extending from the shoreline toward the deep ocean is termed the
a.
b.
c.
d.
e.
5.
Terrigenous sediment
Biogenous sediment
Hydrogenous sediment
All of the above
A and b only
Minerals such as calcite that crystallize directly from seawater are examples of
a.
b.
c.
d.
e.
9.
Terrigenous sediment
Biogenous sediment
Hydrogenous sediment
Both terrigenous sediment and biogenous sediment
Terrigenous sediment, biogenous sediment, and hydrogenous sediment
Manganese nodules are an example of
a.
b.
c.
d.
e.
8.
Terrigenous sediment
Biogenous sediment
Hydrogenous sediment
Both terrigenous sediment and biogenous sediment
Terrigenous sediment, biogenous sediment, and hydrogenous sediment
Calcareous ooze and siliceous ooze are an example of
a.
b.
c.
d.
e.
7.
Continental shelf
Continental slope
Continental rise
Submarine canyon
Ocean basin
Ocean floor sediments derived primarily from the products of weathering on the continents are called
a.
b.
c.
d.
e.
6.
Mid -ocean ridges
Metal-rich sulfide deposits
Hydrothermal vents
All of these
Only mid -ocean ridges and metal sulfides deposits
Terrigenous sediment
Biogenous sediment
Hydrogenous sediment
Both terrigenous sediment and biogenous sediment
Terrigenous sediment, biogenous sediment, and hydrogenous sediment
The _______ represents rapid temperature change with depth and is more pronounced in the _____
latitudes.
a.
b.
c.
d.
e.
thermocline; low
pycnocline; low
halocline; low
thermocline; high
pycnocline; high
10.
Most available information favors the view that submarine canyons on the continental slope
have been generated by
a.
b.
11.
Turbidity currents
Tides
Why is a pycnocline NOT found at high latitudes?
a. The transition zone occurs below the floor of the ocean.
b. The transition zone cannot occur with the warm temperatures associated with high latitudes.
c. There is no transition zone between the warm, low-density surface water and the warm, lowdensity deep water.
d. There is no transition zone between the warm, low-density surface water and the cold, highdensity deep water.
e. There is no transition zone between the cold, high-density surface water and the cold, highdensity deep water at high latitudes.
12.
Deep-ocean circulation is referred to as _____ circulation and is driven by ______ differences.
a.
b.
c.
d.
13.
Thermocline, temperature
Pycnocline, density
Thermohaline, density
Coriolis, latitude
The development of this instrument greatly enhanced our knowledge of the ocean floor.
a.
b.
c.
d.
e.
Pulsar
Echo sounder
Submarine transit
Tuzometer
Infrared scanner
14.
The continents cover approximately _____ percent of Earth's surface.
a. 30
b. 40
c. 50
d. 60
e. 70
15.
The _______ Ocean is the largest ocean.
a.
b.
c.
d.
16.
Which one of the following salts is most abundant in seawater?
a.
b.
c.
d.
e.
17.
Atlantic
Pacific
Indian
Arctic
Potassium bromide
Magnesium chloride
Sodium bicarbonate
Sodium chloride (halite)
Hydrogen borate
The oldest ocean floor rock is about _____ years of age
a.
b.
c.
d.
18
The continental margin off of the west coast of South America is very similar to the continental margin
off of the east coast of North America, both are active continental margins.
a.
b.
19.
20.
True
False
A flat-topped seamount is termed a guyot
a.
True
b.
False
Calcareous shells will not accumulate on the ocean floor when the water depth exceeds about 4500
meters (15,000 feet), because the waters are
a.
b.
c.
21.
Cold and acid
Warm and acid
None of the above
There is a volcanic, hot, and poisonous location on the deep ocean floor at mid-ocean ridges, with
unusual abundance of marine life, It is called:
a.
b.
c.
d.
e.
22.
Continental shelf
Continental slope
Hydrothermal vent
Abyssal plain
a and c
Which is the correct ordering of the passive margin's subdivisions?
a
b
c.
d.
23.
Active continental margin
Passive continental margin
None of the above
An active continental margin is defined by these features:
a.
b.
c.
d.
e.
25.
Continental shelf-Continental slope-Continental rise-Abyssal plain
Continental shelf-Abyssal Plain-Continental rise-Continental slope
Abyssal plain- Continental rise-Continental slope-Continental shelf
Continental rise-Continental shelf-Continental slope-Abyssal plain
The western coast of the US is an
a.
b.
c.
24.
2 billion
200 million
4.5 billion
15 billion
Acretionary wedge
Trench
Subducting plate
All of the above
a only
A passive continental margin is defined by these features:
a.
b.
Continental slope
Submarine canyons
c.
d.
e.
26.
Hydrothermal vents
All of the above
a and b
The Eastern coast of US and the western coast of Europe and Africa are examples of
a.
b.
c.
d.
27.
Passive continental margin
Active continental margin
Black smokers
None of the above
Between the continental margin and the mid-ocean ridge lies the ocean basin
a.
b.
28.
True
False
Which one of these three subdivisions of a passive continental margin can be considered an extension of
the continent under sea (a flooded extension of the continent)?
a.
b.
c.
d.
29.
Continental slope
Continental rise
Continental shelf
Abyssal plain
Which one of these features belongs to an active continental margin?
a.
b.
30.
Trench
Submarine canyons
Concerning the distribution of land and water, which of the following statements is true?
a.
The percentage of land and water is about the same in both the Northern and Southern
Hemispheres.
The Southern Hemisphere has much more water surface than the Northern Hemisphere
b.
Extra Credit Questions (4% each, total 20%):
1
Rock gypsum is a
a.
b.
c.
d.
e
2
Detrital sedimentary rock
Chemical organic sedimentary rock
Chemical inorganic sedimentary rock
Evaporite
c and d
The upper limit of the zone of saturation in an aquifer defines the
a.
b.
c.
d.
e.
Water table
Cone of depression
Capillary fringe
Aquitard
None of the above
3
Halite is composed of these atoms
a.
b.
c.
d.
e.
4.
Sodium (Na) and Chlorine (Cl) atoms
Iron and Magnesium atoms
Copper and water molecules
Silver and gold atoms
None of the above
What type of magma would be prevalent in mid-ocean ridges (ocean floor)?
a.
b.
c.
Mafic (basaltic)
Felsic (granitic)
Andesitic (mix)
5.
When magma cools slowly first, inside and completes the rest of its cooling rapidly outside the
Earth crust, what would be the texture of the resulting rock?
a.
b.
c.
Phaneritic
Porphyritic
Aphanitic