Test bank earth science 12e ch13

Earth Science, 13e (Tarbuck)
Chapter 13 The Ocean Floor
1) Which one of the following is NOT part of the continental margin?
A) continental shelf
B) continental slope
C) continental rise
D) continental trench
Answer: D
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
2) It is thought that submarine canyons on the continental slope have been generated by
________.
A) streams when sea level was much lower than it is today
B) streams when sea level was much higher than it is today
C) a submarine glaciations
D) turbidity currents
Answer: D
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Applying
3) Which one of the following would most likely be covered with thick turbidite layers?
A) axial rift zone of an active mid-ocean spreading center
B) upper part of a steep, narrow, submarine canyon
C) deep-sea fan at the base of a continental slope
D) ocean floor around a conical-shaped seamount
Answer: C
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Applying
4) Which of the following is NOT true of deep ocean trenches?

A) They are long and narrow depressions.
B) They are sites where plates plunge back into the mantle.
C) They are geologically very stable.
D) They may act as sediment traps.
Answer: D
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Understanding

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5) The BEST definition of the outer edge of the continental shelf is that point where ________.
A) the gradient becomes very gentle
B) the water depth reaches 100 fathoms
C) it meets an oceanic ridge
D) a rapid steepening of the gradient occurs
Answer: D
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
6) Seamounts ________.
A) are a special type of oceanic trench
B) are volcanoes that form on the ocean floor
C) form only in the Pacific Ocean basin
D) are submarine canyons found near Australia
Answer: B
Diff: 1

Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering
7) Submarine canyons found on the continental slope are believed to have been created
________.
A) by rivers during the ice age
B) by faulting
C) because of a plate plunging into the mantle
D) none of these
Answer: D
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Remembering
8) Which of the following is associated with ocean ridges?
A) rift zones
B) mountainous topography
C) volcanic structures
D) all of these
Answer: D
Diff: 1
Topic: 13.5 The Oceanic Ridge
Bloom's: Understanding

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9) How do calcareous oozes form?
A) The particles are precipitated in warm surface waters and sink to the bottom.
B) The particles are precipitated by bottom-dwelling organisms.

C) The particles are precipitated in the water column below the depth of sunlight penetration and
then sink to the bottom.
D) The particles settle out from calcite-rich turbidity currents at depths greater than 15,000 feet.
Answer: A
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
10) Sediments derived primarily from the products of weathering on the continents are called
________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Answer: A
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
11) Manganese nodules are an example of ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment
D) both terrigenous and biogenous sediment
Answer: C
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
12) Minerals that crystallize directly from seawater are examples of ________.
A) terrigenous sediment
B) biogenous sediment
C) hydrogenous sediment

D) both terrigenous and biogenous sediment
Answer: C
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Understanding

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13) The gently sloping submerged surface extending from the shoreline toward the deep ocean is
termed the ________.
A) continental shelf
B) continental slope
C) continental rise
D) submarine canyon
Answer: B
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
14) The crests of mid-oceanic ridges ________.
A) are heavily mantled with sediment
B) lie at depths exceeding 6 kilometers
C) contain active rift zones
D) are geologically old features
Answer: C
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Understanding

15) ________ develop where oceanic lithosphere bends downward and sinks into the mantle.
A) Submarine canyons
B) Abyssal seamounts
C) Deep ocean trenches
D) Rift valleys on mid-ocean ridges
Answer: C
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
16) An echo sounder operates by measuring the time required for a ________.
A) light beam to travel from a satellite at a known altitude to the sea bottom and back
B) radar beam to travel from a harbor patrol boat to a fuzz-buster on a speeding yacht
C) radar beam to travel from a ship to the seafloor and back
D) sound pulse travels from a ship to the seafloor and back
Answer: D
Diff: 1
Topic: 13.2 An Emerging Picture of the Ocean Floor
Bloom's: Understanding

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17) The oceans cover approximately ________ percent of Earth's surface.
A) 40
B) 50
C) 60
D) 70
Answer: D

Diff: 1
Topic: 13.1 The Vast Ocean World
Bloom's: Remembering
18) The ________ Ocean is largest.
A) Atlantic
B) Pacific
C) Indian
D) Arctic
Answer: B
Diff: 1
Topic: 13.1 The Vast Ocean World
Bloom's: Remembering
19) Which ocean has the greatest average depth?
A) Atlantic
B) Pacific
C) Indian
D) Arctic
Answer: B
Diff: 1
Topic: 13.1 The Vast Ocean World
Bloom's: Remembering
20) 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.
B) The Southern Hemisphere has much more water surface than the Northern Hemisphere.
C) The Northern Hemisphere has much more water surface than the Southern Hemisphere.
D) None of the above is true.
Answer: B
Diff: 1
Topic: 13.1 The Vast Ocean World

Bloom's: Remembering

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21) The continental rise is located ________.
A) at the top of a mid-ocean ridge
B) at the top of the continental slope
C) between an abyssal plain and continental slope
D) at the seaward edge of a deep ocean trench
Answer: C
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
22) Which one of the following concerning mid-ocean ridges is false?
A) They are sites for submarine eruptions of basaltic lava.
B) They are where young lithosphere is added to the edges of spreading, oceanic plates.
C) Terrigenous sediment coverings are very thin or absent.
D) Sediments include thick siliceous ooze deposits and sandy turbidite beds.
Answer: D
Diff: 1
Topic: 13.5 The Oceanic Ridge
Bloom's: Understanding
23) The ________ Ocean has more extensive abyssal plains than the Pacific Ocean because it
has fewer trenches to trap sediments moving down the continental slope.
A) Indian
B) Atlantic
C) Arctic

D) none of these
Answer: B
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering
24) "Black smokers" are associated with ________.
A) oceanic ridges
B) mineral-rich waters
C) hot water
D) all of these
Answer: D
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Applying

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Give the term of ocean floor sediment for each phrase.
biogenous

terrigenous

hydrogenous

25) manganese nodule
Answer: hydrogenous
Diff: 1

Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
26) calcareous ooze
Answer: biogenous
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
27) abyssal plain clay
Answer: terrigenous
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
Word Analysis. Examine the words and/or phrases for each question below and determine the
relationship among the majority of words/phrases. Choose the option which does not fit the
pattern.
28) echo sounder
doppler radar
sidescan sonar
Answer: Doppler radar
Diff: 2
Topic: 13.2 An Emerging Picture of the Ocean Floor
Bloom's: Understanding
29) continental shelf
continental rise
Answer: continental volcanic arc
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
30) rift valley
subduction

Answer: rift valley
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Understanding

continental slope

radar altimeters

continental volcanic arc

volcanic island arc

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trench


31) manganese nodules
calcareous ooze
Answer: evaporites
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Understanding

metal sulfides

evaporites

32) The west coast of South America and the east coast of North America have very different
continental margins.
Answer: TRUE
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Remembering
33) Abyssal plains with sediments covering the seafloor igneous rocks are more extensive in the
central Pacific basin than in the North Atlantic.
Answer: FALSE
Diff: 1
Topic: Figure 13.13
Bloom's: Remembering
34) Submerged, flat-topped seamounts are known as guyots.
Answer: TRUE
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering
35) The Atlantic and Pacific basins have oceanic ridges; the Indian Ocean has no oceanic ridge.
Answer: FALSE
Diff: 1
Topic: Figure 13.15
Bloom's: Remembering
36) Manganese nodules do not accumulate below 4500 meters depth because the manganese
minerals are highly soluble in seawater below that depth.
Answer: FALSE
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
37) Turbidites and siliceous oozes are both biogenous sediments.

Answer: FALSE
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering

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38) Submarine canyons form the deepest parts of the ocean basins.
Answer: FALSE
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
39) Compared to the Southern Hemisphere, a higher percentage of the Northern Hemisphere is
water covered.
Answer: FALSE
Diff: 1
Topic: Figure 13.1
Bloom's: Remembering
40) The continental rise lies at the bottom of the continental slope.
Answer: TRUE
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
41) Seafloor hot springs occur mainly in oceanic, abyssal plains.
Answer: FALSE
Diff: 1
Topic: 13.4 The Deep Ocean Basin

Bloom's: Understanding
42) Sand, silt, and clays deposited on the ocean floor are described as terrigenous sediments.
Answer: TRUE
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
43) The most extensive mountain range on Earth extends for about 65,000 kilometers on the
ocean floor and is known as the ________.
Answer: mid-ocean ridge
Diff: 1
Topic: 13.5 The Oceanic Ridge
Bloom's: Remembering
44) Flat-topped volcanic structures located on the floor of the deep ocean basin are termed
________.
Answer: guyots
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering

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45) A prominent feature of the Mid-Atlantic Ridge is a very deep linear valley known as a(n)
________ valley.
Answer: rift
Diff: 1
Topic: 13.5 The Oceanic Ridge
Bloom's: Remembering

46) The gently sloping submerged surface extending from the shoreline toward the deep ocean is
termed the ________.
Answer: continental shelf
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Remembering
47) ________ sediment consists of shells and hard parts of marine organisms.
Answer: Biogenous
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
48) Valleys that lead from the continental shelf into deeper waters are known as ________.
Answer: submarine canyons
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Remembering
49) ________ continental margins typically exhibit wide, extensive, continental shelves.
Answer: Passive
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Understanding
50) Manganese nodules are an example of ________ sediment.
Answer: hydrogenous
Diff: 1
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Remembering
51) A(n) ________ is a volcanic mountain, built up from the seafloor that never reached the sea
surface.
Answer: seamount
Diff: 1

Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering

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52) ________ continental margins occur where oceanic lithosphere is being subducted beneath
the edge of a continent.
Answer: Active
Diff: 1
Topic: 13.3 Continental Margins
Bloom's: Remembering
53) A(n) ________ is the vast, relatively deep, flat, sediment-covered portion of the deep-ocean
basin.
Answer: abyssal plain
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering
54) A(n) ________ marks the site where old, oceanic lithosphere begins its descent into a
subduction zone.
Answer: trench
Diff: 1
Topic: 13.4 The Deep Ocean Basin
Bloom's: Remembering
Critical Thinking and Discussion. Use complete sentences, correct spelling, and the
information presented in Chapter 13 to answer the questions below.
55) Discuss the distribution of seafloor sediments in the ocean basins. What are the different
types of sediments, and what are the factors that control their distribution (geologic setting,

climate, etc.)?
Answer: The sediments nearest the continents are a record of terrestrial occurrences on Earth.
The sediments on the abyssal plain are a record of happenings in the photic zone of the ocean.
The sediments are wedge-shaped, being thinnest at the divergent boundary (mid-ocean ridge) and
thickest next to the continents.
Diff: 2
Topic: 13.6 Types of Seafloor Sediment
Bloom's: Applying

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56) What type of continental margin is illustrated in the diagram below?

Answer: active continental margin
Diff: 1
Topic: Figure 13.11
Bloom's: Understanding

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57) Examine Figure 13.B from Earth Science, 13e below. Briefly explain the main points of
Charles Darwin's hypothesis on coral atoll formation. Have we tested his hypothesis and is it still
thought to be correct today? Can you think of another possible explanation that would explain
the origin of such coral atolls?

Answer: Corals colonize and ring a volcanic island once it’s been formed. Then, erosion attacks
the top of the volcano and the plat also sinks when its away from the hotspot. The corals have to
grow upwards as a result, because they need light. Eventually their growth doesn't keep pace
with the sinking and the reef is submerged, becoming a seamount.
Diff: 2
Topic: Box 13.1
Bloom's: Analyzing

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