Question 1

The lowest point on earth is in the ________ Ocean.

Accepted Answer

The answer of The lowest point on earth is in...

Question 2

In the present day,what is the most valuable non-living commodity obtained from sea floor?

Accepted Answer

A)  sand and gravel
B)  gold
C)  oil and gas
D)  gas hydrate

Question 3

A geologist is studying sediments on land that were originally deep sea sediments.She finds the minerals zircon and garnet in the sediments,which could only come from a continental region.These sediments must be ________.

Accepted Answer

A)  terrigenous sediment
B)  biogenous sediment
C)  hydrogenous sediment
D)  both terrigenous and biogenous sediment

Question 4

Sailors in the 16th-18th century dreaded "rounding the horn" because of strong winds and heavy seas.Cape Horn is about latitude 55°S at the tip of South America.These sailors considered this a passage from the Atlantic to Pacific oceans,but this ocean is now often called ________.

Accepted Answer

A)  the Southern Ocean
B)  the Antarctic Ocean
C)  the Australian Ocean
D)  the Indian Ocean

Question 5

Sediments derived primarily from the products of weathering on the continents are called ________.

Accepted Answer

A)  terrigenous sediment
B)  biogenous sediment
C)  hydrogenous sediment
D)  both terrigenous and biogenous sediment

Question 6

The best modern technique for obtaining high resolution bathymetry of the seafloor is ________.

Accepted Answer

A)  sidescan sonar
B)  echo sounding
C)  seismic reflection profiling
D)  multibeam bathymetry

Question 7

echo sounder Doppler radar sidescan sonar radar altimeters

Accepted Answer

The answer of echo sounder Doppler radar sidescan sonar radar...

Question 8

Deep sea trenches are important features for plate tectonic studies because ________.

Accepted Answer

A)  they are sites where oceanic lithosphere is formed
B)  they are sites where two plate move past each other horizontally
C)  they are sites where the oceanic lithosphere is consumed into the mantle
D)  none of the above

Question 9

If Yellowstone were on the ocean floor,it would produce ________.

Accepted Answer

A)  a chain of line islands,like Hawaii
B)  an island arc
C)  a trench
D)  a mid-ocean ridge

Question 10

rift valley subduction volcanic island arc trench

Accepted Answer

The answer of rift valley subduction volcanic island arc trench...

Question 11

Manganese nodules do not accumulate below 4500 meters depth because the manganese minerals are highly soluble in seawater below that depth.

Accepted Answer

A) True 
 B)False

Question 12

Much of the Gulf of Mexico is underlain by large thicknesses of salt that formed in a small ocean basin like the red sea,as the north Atlantic spreading began in Mesozoic time.This salt is a good example of ________.

Accepted Answer

A)  terrigenous sediment
B)  biogenous sediment
C)  hydrogenous sediment
D)  both terrigenous and biogenous sediment

Question 13

When organisms living in seawater grow shells,the ratio between the isotopes of oxygen (18O/16O) trapped in their shell is dependent on the sea temperature.Why might geologists collect these sea shells from deep-sea sediments that are Pleistocene in age and measure their oxygen isotope ratios?

Accepted Answer

A)  They might want to know how cold the water was at the seafloor in the past.
B)  They want to know how metabolism of the organism affects the oxygen isotope ratios.
C)  The organisms live in the photic zone,and so photosynthesis must be the main factor in the oxygen content.
D)  The organisms live near the surface,so their oxygen isotope ratios record surface temperature during Earth's great climate fluctuations of the ice age.

Question 14

The principal technique for finding ocean depth today is ________.

Accepted Answer

sonar (or ...

Question 15

The continental rise lies at the bottom of the continental slope.

Accepted Answer

A) True 
 B)False

Question 16

The most extensive mountain range on Earth extends for about 65,000 kilometers on the ocean floor and is known as the ________.

Accepted Answer

The answer of The most extensive mountain range on Earth...

Question 17

The most important economic resource in the ocean today is ________.

Accepted Answer

The answer of The most important economic resource in the...

Question 18

Why isn't manganese mined on the seabed when there are abundant manganese nodules in some parts of the ocean floor?

Accepted Answer

A)  The manganese is too difficult to extract from the nodules; a new technology is needed.
B)  It is not economical to mine manganese nodules at present-day world prices for manganese and associated metals in nodules.
C)  The manganese market is held by a global cartel who prevent the material from being mined.
D)  It is impossible to extract the nodules from the seafloor with present-day technology.

Question 19

Multibeam provides the best modern technique for obtaining seafloor bathymetry,so why hasn't it been used for the entire ocean?

Accepted Answer

A)  It is too expensive,requiring many ships many years to survey the entire ocean.
B)  It doesn't work in deep water.
C)  It doesn't work where there is ice.
D)  Oceanographers simply haven't had time to process all the data.

Question 20

Which one of the following is not part of the continental margin?

Accepted Answer

A)  continental shelf
B)  continental slope
C)  continental rise
D)  continental trench

Exam 13: The Ocean Floor

The principal technique for finding ocean depth today is ________.

Correct Answerverifiedsonar (or ...View AnswerShow Answer

The lowest point on earth is in the ________ Ocean.

Correct AnswerverifiedShow Answer

The most extensive mountain range on Earth extends for about 65,000 kilometers on the ocean floor and is known as the ________.

Correct AnswerverifiedShow Answer

The continental rise lies at the bottom of the continental slope.

Correct AnswerverifiedShow Answer

A geologist is studying sediments on land that were originally deep sea sediments.She finds the minerals zircon and garnet in the sediments,which could only come from a continental region.These sediments must be ________.

Correct AnswerverifiedShow Answer

In the present day,what is the most valuable non-living commodity obtained from sea floor?

Correct AnswerverifiedShow Answer

Deep sea trenches are important features for plate tectonic studies because ________.

Correct AnswerverifiedShow Answer

If Yellowstone were on the ocean floor,it would produce ________.

Correct AnswerverifiedShow Answer

When organisms living in seawater grow shells,the ratio between the isotopes of oxygen (18O/16O) trapped in their shell is dependent on the sea temperature.Why might geologists collect these sea shells from deep-sea sediments that are Pleistocene in age and measure their oxygen isotope ratios?

Correct AnswerverifiedShow Answer

The best modern technique for obtaining high resolution bathymetry of the seafloor is ________.

Correct AnswerverifiedShow Answer

The most important economic resource in the ocean today is ________.

Correct AnswerverifiedShow Answer

Much of the Gulf of Mexico is underlain by large thicknesses of salt that formed in a small ocean basin like the red sea,as the north Atlantic spreading began in Mesozoic time.This salt is a good example of ________.

Correct AnswerverifiedShow Answer

Manganese nodules do not accumulate below 4500 meters depth because the manganese minerals are highly soluble in seawater below that depth.

Correct AnswerverifiedShow Answer

Sediments derived primarily from the products of weathering on the continents are called ________.

Correct AnswerverifiedShow Answer

rift valley subduction volcanic island arc trench

Correct AnswerverifiedShow Answer

Sailors in the 16th-18th century dreaded "rounding the horn" because of strong winds and heavy seas.Cape Horn is about latitude 55°S at the tip of South America.These sailors considered this a passage from the Atlantic to Pacific oceans,but this ocean is now often called ________.

Correct AnswerverifiedShow Answer

echo sounder Doppler radar sidescan sonar radar altimeters

Correct AnswerverifiedShow Answer

Multibeam provides the best modern technique for obtaining seafloor bathymetry,so why hasn't it been used for the entire ocean?

Correct AnswerverifiedShow Answer

Why isn't manganese mined on the seabed when there are abundant manganese nodules in some parts of the ocean floor?

Correct AnswerverifiedShow Answer

Which one of the following is not part of the continental margin?

Correct AnswerverifiedShow Answer

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