Chapter 3

Question 1

Satellites are used to map the ocean floor because _______.

Answer 1

Gravitational bulges in sea surface

Question 2

The two relatively flat areas on the hypsographic curve represent ____.

Answer 2

Abyssal plain, continental shelf

Question 3

The correct order of seafloor features from the coast to the mid-ocean ridge is _______.

Answer 3

Continental shelf, continental slope, continental rise, abyssal plane

Question 4

Active continental margins are characterized by which of the following?

Answer 4

Convergent/transform boundaries, ocean trench, seamounts

Question 5

Characteristics of passive continental margins include which of the following?

Answer 5

Broad continental shelves

Question 6

Which of the following features is related to transform faults along mid-ocean ridges?

Answer 6

Fracture zones

Question 7

Directly seaward of the continental shelf is a more steeply sloping region called the ______.

Answer 7

Shelf break

Question 8

Underwater avalanches of muddy water mixed with rocks and debris are _______.

Answer 8

Turbidity currents

Question 9

Submarine canyons were most likely formed by _______.

Answer 9

Turbidity currents

Question 10

Extending from the base of the continental rises into the deep-ocean basins are flat depositional surfaces called ______.

Answer 10

Abyssal plains

Question 11

Relatively few abyssal plains are located in the Pacific ocean due to ______.

Answer 11

The presence of convergent active margins

Question 12

Volcanic peaks on the deep-ocean floor with conical tops are called:

Answer 12

Seamounts

Question 13

Along the margins of the Pacific are found most of Earth’s ___.

Answer 13

Earthquakes/volcanoes

Question 14

Older lithosphere is destroyed in association with:

Answer 14

Deep sea trenches

Question 15

Oceanic ridges and rises result from seafloor spreading along ______.

Answer 15

Divergent plate boundaries

Question 16

New lithosphere is produced in association with ____.

Answer 16

Oceanic ridges

Question 17

Segments of the oceanic ridge system that are gentler and less rugged in slope due to faster rates of seafloor spreading are called

Answer 17

Oceanic rises

Question 18

The direction of motion along a seafloor transform fault is ______.

Answer 18

In the same direction that the plates are spreading

Question 19

With respect to mid-ocean ridges, transform faults are _______.

Answer 19

Perpendicular to the ridge axis

Question 20

Seamounts and abyssal hills are _____ in origin.

Answer 20

Volcanic

Question 21

Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a pointy top like an upside-down ice cream cone are called ______.

Answer 21

Seamounts

Question 22

Volcanic peaks that are below sea level but rise more than 1 kilometer above the deep-ocean floor and have a flattened top are called ______.

Answer 22

Tablemounts

Question 23

Volcanic features on the ocean floor that are less than 1000 meters tall are called:

Answer 23

Seaknolls (abyssal hills)

Question 24

What percent of Earth’s volcanic activity, each year, takes place on the seafloor?

Answer 24

80%

Question 25

The Big Island of Hawaii is an example of a volcanic island associated with volcanic activity at a _______.

Answer 25

Hotspot

Question 26

Which of the following is an example of a passive continental margin?

Answer 26

Atlantic

Question 27

Passive margins are usually produced over geologic time by which of the following?

Answer 27

Continental rifting and continued seafloor spreading

Question 28

The average slope of the continental shelf is approximately _____.

Answer 28

A 10th of a degree

Question 29

The average slope of the continental shelf is similar to the slope of which of the following?

Answer 29

Parking lot

Question 30

Where does the deep-ocean basin begin along a passive continental margin?

Answer 30

Continental slope

Question 31

Deep-ocean trenches and volcanic arcs result from the collision of two plates at convergent plate boundaries and mostly occur along the margins of which of the following oceans?

Answer 31

Pacific ocean

Question 32

Where are the deepest portions of the world’s oceans found?

Answer 32

At convergent plate boundaries

Question 33

Oceanic ridges and rises result from seafloor spreading along _______.

Answer 33

Divergent plate boundaries

Question 34

Along the margins of the Pacific are found most of Earth’s _____.

Answer 34

Oceanic trenches