Question 1

What methods do scientists use to determine the bathymetry of the ocean floor?

Accepted Answer

Scientists use information from many differences sources to get a clearer idea of the details of the ocean floor. Echo sounders are used to bounce sound waves off the seafloor. A beam of sound waves is emitted from a ship at the surface and as they hit the bottom, the sound waves are reflected back to the ship. The depth is determined by D=V (T/2) where V is the velocity of the sound waves, T is time it takes for the sound waves to travel away from and back to the ship. Another method is called a multi-beam echo sounder system which uses many beams (up to 121) that radiate from a ship. When the ship moves along a transect pattern, like mowing the lawn, the echo sounder information from all the beams combined gives scientists a fairly accurate map of greater areas of the ocean floor. A third system uses satellites to gather information about the ocean floor. Since satellites cannot measure the ocean floor directly, they measure small variations in the elevation of the surface water. Features of the ocean floor can be determined by measuring subtle irregularities of the sea surface. Lastly remote operated vehicles or deep sea submersibles descend to the deep sea to measure, photograph and collect information about the ocean floor.

Question 2

Which of the following statements most accurately describes how the continental rise is formed?

Accepted Answer

A)  From the convergence of oceanic plates at passive continental margins. 
B)  From volcanic activity at active continental margins. 
C)  From accumulated sediments at the base of the continental slope. 
D)  from sedimentation surrounding spreading centers. 
A)  From the convergence of oceanic plates at passive continental margins. 
B)  From volcanic activity at active continental margins. 
C)  From accumulated sediments at the base of the continental slope. 
D)  from sedimentation surrounding spreading centers. C

Question 3

The average elevation of the continents is:

Accepted Answer

A)  8,848 meters (16,000 feet) 
B)  840 meters (2,760 feet) 
C)  3,800 meters (12,000 feet) 
D)  5,000 meters (15,000 feet) 
A)  8,848 meters (16,000 feet) 
B)  840 meters (2,760 feet) 
C)  3,800 meters (12,000 feet) 
D)  5,000 meters (15,000 feet) B

Question 4

The Challenger expedition used multibeam echo sounders to contour the seafloor.

Accepted Answer

A) True 
 B)False

Question 5

Scientists think that turbidity currents contribute to the formation of submarine canyons.

Accepted Answer

A) True 
 B)False

Question 6

Submarine canyons:

Accepted Answer

A)  always run parallel to coasts. 
B)  have gradual slopes and are very wide. 
C)  can never cut into rock. 
D)  cut into the shelf and may extend almost to the shore. 
A)  always run parallel to coasts. 
B)  have gradual slopes and are very wide. 
C)  can never cut into rock. 
D)  cut into the shelf and may extend almost to the shore.

Question 7

A guyot is found at spreading centers.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following statements accurately describes a turbidity current?

Accepted Answer

A)  A fast dense current of water that carries sediments offshore. 
B)  The cause of mid-ocean trenches. 
C)  A phenomenon associated with violent atmospheric storms at sea. 
D)  Something that always occurs at river mouths in shallow water, but does not extend into water more than 50 meters (165 feet) deep. 
A)  A fast dense current of water that carries sediments offshore. 
B)  The cause of mid-ocean trenches. 
C)  A phenomenon associated with violent atmospheric storms at sea. 
D)  Something that always occurs at river mouths in shallow water, but does not extend into water more than 50 meters (165 feet) deep.

Question 9

The discovery and study of ocean floor contours is called:

Accepted Answer

A)  bathymetry. 
B)  abyssomethry. 
C)  stratigraphy. 
D)  paleoceanography. 
A)  bathymetry. 
B)  abyssomethry. 
C)  stratigraphy. 
D)  paleoceanography.

Question 10

The Andes mountain range is an example of a(n):

Accepted Answer

A)  ridge system. 
B)  island arc system. 
C)  passive margin. 
D)  active margin convergent zone. 
A)  ridge system. 
B)  island arc system. 
C)  passive margin. 
D)  active margin convergent zone.

Question 11

How can a satellite sense the contours of the ocean bottom from space?

Accepted Answer

A)  By shining a laser through the ocean to see the bottom. 
B)  By using radar to sense the height of the sea surface over submerged features. 
C)  By using sonar to measure ocean bottom contours directly. 
D)  By sensing changes in gravity as it flies over trenches and mountain ranges. 
A)  By shining a laser through the ocean to see the bottom. 
B)  By using radar to sense the height of the sea surface over submerged features. 
C)  By using sonar to measure ocean bottom contours directly. 
D)  By sensing changes in gravity as it flies over trenches and mountain ranges.

Question 12

The leading edge of a moving continental crustal plate is most likely to exhibit features associated with:

Accepted Answer

A)  frequent earthquake activity. 
B)  active continental margins. 
C)  widespread volcanism. 
D)  passive continental margins. 
A)  frequent earthquake activity. 
B)  active continental margins. 
C)  widespread volcanism. 
D)  passive continental margins.

Question 13

An example of a continental rise that is extraordinarily wide is found:

Accepted Answer

A)  in the Red Sea. 
B)  in the Pacific at the active margin called the "Ring of Fire." 
C)  in the Bay of Bengal. 
D)  off the east coast of Florida. 
A)  in the Red Sea. 
B)  in the Pacific at the active margin called the "Ring of Fire." 
C)  in the Bay of Bengal. 
D)  off the east coast of Florida.

Question 14

The deep-ocean basin includes all of the following features EXCEPT:

Accepted Answer

A)  continental shelf. 
B)  abyssal hills. 
C)  abyssal plains. 
D)  mid-ocean ridges. 
A)  continental shelf. 
B)  abyssal hills. 
C)  abyssal plains. 
D)  mid-ocean ridges.

Question 15

Hydrothermal vents such as black smokers are found at spreading centers.

Accepted Answer

A) True 
 B)False

Question 16

The transition between the shelf and the deep seafloor is:

Accepted Answer

A)  the littoral zone. 
B)  the continental slope and rise. 
C)  the abyssal plain. 
D)  the mid-ocean ridge. 
A)  the littoral zone. 
B)  the continental slope and rise. 
C)  the abyssal plain. 
D)  the mid-ocean ridge.

Question 17

Continental shelves can be made of either granite crust, basalt crust or both.

Accepted Answer

A) True 
 B)False

Question 18

Active continental margins are located:

Accepted Answer

A)  along the east coast of the United States. 
B)  along the east coast of South America. 
C)  on the west coasts of both North and South America. 
D)  all around Africa. 
A)  along the east coast of the United States. 
B)  along the east coast of South America. 
C)  on the west coasts of both North and South America. 
D)  all around Africa.

Question 19

The deepest part of the ocean is the:

Accepted Answer

A)  Peru-Chile Trench. 
B)  Mid-Atlantic Ridge. 
C)  Mariana Trench. 
D)  Abyssal plains. 
A)  Peru-Chile Trench. 
B)  Mid-Atlantic Ridge. 
C)  Mariana Trench. 
D)  Abyssal plains.

Question 20

Passive continental margins line coasts that are far from tectonically active areas.

Accepted Answer

A) True 
 B)False

What methods do scientists use to determine the bathymetry of the ocean floor?

Which of the following statements most accurately describes how the continental rise is formed?

The average elevation of the continents is:

The Challenger expedition used multibeam echo sounders to contour the seafloor.

Scientists think that turbidity currents contribute to the formation of submarine canyons.

Submarine canyons:

A guyot is found at spreading centers.

Which of the following statements accurately describes a turbidity current?

The discovery and study of ocean floor contours is called:

The Andes mountain range is an example of a(n):

How can a satellite sense the contours of the ocean bottom from space?

The leading edge of a moving continental crustal plate is most likely to exhibit features associated with:

An example of a continental rise that is extraordinarily wide is found:

The deep-ocean basin includes all of the following features EXCEPT:

Hydrothermal vents such as black smokers are found at spreading centers.

The transition between the shelf and the deep seafloor is:

Continental shelves can be made of either granite crust, basalt crust or both.

Active continental margins are located:

The deepest part of the ocean is the:

Passive continental margins line coasts that are far from tectonically active areas.

The Origin of the Ocean

A History of Marine Science

Earth Structure and Plate Tectonics

Ocean Sediments

Water

Atmospheric Circulation

Ocean Circulation

Waves

Tides

Coasts

Life in the Ocean

Pelagic Communities

Benthic Communities

Uses and Abuses of the Ocean

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Exam 4: Ocean Basins

What methods do scientists use to determine the bathymetry of the ocean floor?

Which of the following statements most accurately describes how the continental rise is formed?

The average elevation of the continents is:

The Challenger expedition used multibeam echo sounders to contour the seafloor.

Scientists think that turbidity currents contribute to the formation of submarine canyons.

Submarine canyons:

A guyot is found at spreading centers.

Which of the following statements accurately describes a turbidity current?

The discovery and study of ocean floor contours is called:

The Andes mountain range is an example of a(n):

How can a satellite sense the contours of the ocean bottom from space?

The leading edge of a moving continental crustal plate is most likely to exhibit features associated with:

An example of a continental rise that is extraordinarily wide is found:

The deep-ocean basin includes all of the following features EXCEPT:

Hydrothermal vents such as black smokers are found at spreading centers.

The transition between the shelf and the deep seafloor is:

Continental shelves can be made of either granite crust, basalt crust or both.

Active continental margins are located:

The deepest part of the ocean is the:

Passive continental margins line coasts that are far from tectonically active areas.

The Origin of the Ocean

A History of Marine Science

Earth Structure and Plate Tectonics

Ocean Sediments

Water

Atmospheric Circulation

Ocean Circulation

Waves

Tides

Coasts

Life in the Ocean

Pelagic Communities

Benthic Communities

Uses and Abuses of the Ocean

Filters