Deck 2: Plate Tectonics and the Ocean Floor

Question 1

All continents fit together with the least number of overlaps and gaps when the continents are matched along:

A) contours at around 2000 meters in depth.
B) current shorelines.
C) edge of the continental shelf.
D) edges of the deep sea floor.
E) oceanic trenches in subduction zones.

Answer 1

A

Question 2

At divergent plate boundaries, only shallow focus earthquakes can be found.

Answer 2

True

Question 3

Water depth decreases as you move away from the mid-ocean ridge.

Answer 3

False

Question 4

The oldest rocks are located at mid-ocean ridges.

Question 5

Earthquakes are common along fracture zones.

Question 6

Fast-moving spreading ridges tend to be more gently sloped than slow-moving ridges.

Question 7

New crust is formed at trenches and old crust is subducted at ridges.

Question 8

Convergent plate boundaries occur when tectonic plates move in opposite directions.

Question 9

Deep-sea trenches are found at convergent plate boundaries.

Question 10

The magnetic north pole has remained very close to the geographic North Pole through all of geologic time.

Question 11

Paleomagnetism confirms that at particular times in the geologic past Earth has had more than one magnetic north pole.

Question 12

Fossils found in sediments can be used to:

A) indicate the relative age of the sediments.
B) provide evidence for plate movement.
C) suggest ancient climate characteristics.
D) support the idea that land masses were joined.
E) all of the above.

Question 13

A rift valley is associated with divergent plate boundaries.

Question 14

The magnetic field of the Earth reverses itself each time that magma erupts at a mid-ocean ridge.

Question 15

Iceland is geologically active because it sits above a hotspot and is located along the mid-Atlantic ridge.

Question 16

The relatively young age of the seafloor supports the idea that subduction must take place.

Question 17

Deep focus earthquakes are often associated with deep-sea trenches.

Question 18

Fossils of ancient polar plants are currently found near the equator because the:

A) entire earth had polar conditions at the time the plants were living.
B) plants lived near the poles, but land masses have drifted to current locations.
C) plants probably were tolerant of both tropical and polar conditions.
D) plants were distributed to current locations by ancient glacial ice sheets.
E) poles were at the equator at times in the geologic past.

Question 19

The seafloor magnetic pattern is best described as:

A) not related to the location of oceanic ridges.
B) parallel to and symmetric about ocean ridges.
C) parallel to, but not symmetric about ocean ridges.
D) perpendicular to and symmetric about ocean ridges.
E) perpendicular to, but not symmetric about ocean ridges.

Question 20

Which of the following is characteristic of oceanic-continental convergent plate boundaries?

A) andesitic volcanoes
B) fracture zones
C) hot spots
D) mid-ocean ridges
E) volcanic island arcs

Question 21

Oceans become deeper moving away from ridges due to:

A) decreasing thickness of the lithosphere.
B) increasing density of oceanic basalts.
C) increases in sediment accumulations.
D) polar wandering.
E) thermal contraction of hot asthenosphere.

Question 22

Deep ocean trenches are associated with:

A) rift valleys.
B) subduction zones.
C) submarine canyons.
D) transform faults.
E) turbidity currents.

Question 23

Which of the following is characteristic of oceanic-oceanic convergent plate boundaries?

A) andesitic volcanoes
B) fracture zones
C) hot spots
D) mid-ocean ridges
E) volcanic island arcs

Question 24

Which of the following is associated with convergent plate boundaries on the seafloor?

A) crest of the mid-ocean ridge
B) deep sea trenches
C) deep focus earthquakes
D) island arcs
E) offset of the mid-ocean ridge

Question 25

Which of the following statements is true of the lithosphere?

A) The lithosphere is composed of outer mantle material.
B) The lithosphere is composed of igneous rock.
C) The lithosphere is composed of metamorphic rock.
D) The lithosphere is composed of the crust and the topmost portion of the outer mantle.
E) The lithosphere is composed of the inner portion of the mantle and the outer core.

Question 26

Which of the following statements is true of the asthenosphere?

A) The asthenosphere is composed of continental and oceanic plates.
B) The asthenosphere is composed of outer mantle material.
C) The asthenosphere is composed of the crust and a portion of the outer mantle.
D) The asthenosphere is composed of the inner portion of the mantle and the outer core.
E) The asthenosphere is composed only of crust.

Question 27

Confirmation of seafloor spreading was supported by the:

A) age of seafloor.
B) apparent polar wandering.
C) magnetic reversals found in continental rocks.
D) match of rocks from distant continents.
E) sediment analysis from different areas of the seafloor.

Question 28

Vine and Matthews determined that new ocean floor was being produced at ocean ridges by examining:

A) apparent polar wandering.
B) fossils in marine sediments.
C) glacial debris at various locations.
D) the location of ancient coral reefs.
E) the magnetic pattern on the seafloor.

Question 29

Differences in height between continental crust and oceanic crust are explained by:

A) continental drift.
B) density.
C) isostasy.
D) ophiolites.
E) paleomagnetism.

Question 30

All of the following provide evidence for continental drift except:

A) age of selected continental rocks.
B) apparent polar wandering.
C) location of coral reef fossils.
D) seafloor magnetic pattern.
E) shape of continental margins.

Question 31

The Hawaiian Islands are located where the Pacific plate is:

A) being subducted beneath the North American plate.
B) being subducted beneath Japan.
C) being thrust over the North American plate.
D) diving under Japan.
E) moving over a hot spot.

Question 32

Moving from oceanic ridge to oceanic trench, the thickness of the lithosphere:

A) decreases in proportion to the distance.
B) is unrelated to the distance from the ridge.
C) increases in proportion to the distance.
D) randomly varies.
E) remains the same.

Question 33

Climate distribution on Earth is primarily controlled by:

A) Earth's geologic history.
B) latitude.
C) longitude.
D) presence or absence of glacial debris.
E) plants and animals that live in an area.

Question 34

The Mid-Atlantic Ridge is an example of a:

A) convergent boundary (continent-continent).
B) convergent boundary (continent-oceanic).
C) convergent boundary (oceanic-oceanic).
D) divergent boundary.
E) transform fault boundary.

Question 35

Which of the following statements best describes the relationship between Earth's geographic and magnetic poles?

A) The geographic pole and the magnetic pole are always the same.
B) The geographic pole wobbles, but stays near the magnetic pole.
C) The geographic poles have reversed themselves periodically through geologic time.
D) The location of the magnetic pole is unrelated to the location of the geographic pole.
E) The magnetic pole wobbles, but stays near the geographic pole.

Question 36

Continental drift was confirmed through the use of the:

A) age of rocks on distant continents.
B) location of ancient coral reefs.
C) location of deep sea trenches.
D) location of magnetic poles through geologic time.
E) the shape of the continental margins.

Question 37

The Hawaiian Islands-Emperor Seamount Chain was formed:

A) at a subduction zone in the Pacific Ocean.
B) by magma from the upper mantle rising to the surface.
C) formed when the Pacific plate moved across a hotspot.
D) is associated with a trench.
E) parallels a Pacific Ocean subduction zone.

Question 38

How is the age of the ocean sediments related to the distance from a mid-ocean ridge?

Question 39

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

A)Aleutian Islands
B)Andes Mountains
C)Hawaiian Islands
D)Japan
E)Mariana Trench

Question 40

Describe the formation of the magnetic pattern on the seafloor.

Question 41

The San Andreas Fault:

A) is a continental transform fault.
B) is an oceanic transform fault.
C) is associated with deep focus earthquakes.
D) lies next to the Mendocino Fracture Zone.
E) is located in the Juan de Fuca Plate.

Question 42

How are convergent and divergent plate boundaries related to constructive and destructive plate margins?

Question 43

Coral reefs:

A) are most common in the tropical portion of the Atlantic Ocean basin.
B) can be found at latitudes above 60º.
C) form when underwater volcanoes are thrust upward during a tectonic event.
D) include atolls, barrier, and fringing reefs.
E) were first described by Christopher Columbus during his voyage to the Caribbean Island of Hispanola.

Question 44

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

A)Gondwanaland
B)Panamerica
C)Pangea
D)Panthalassa
E)Tethys Sea

Question 45

How does convection in the asthenosphere explain ocean basin features, heat flow, and lithosphere thickness?

Question 46

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

A)Aleutian Islands
B)Canary Islands
C)Galapagos Islands
D)Hawaiian Islands
E)Iceland

Question 47

Discuss changes in the lithosphere that occur between a ridge and a trench.

Question 48

Briefly discuss four important evidences that support continental drift.

Question 49

Why are earthquakes associated with plate boundaries?

Question 50

All of the following are true of the Wilson Cycle except:

A) the Wilson Cycle is a technique used to date ocean sediments.
B) the Wilson Cycles describes the formation of seafloor features.
C) the Wilson Cycle predicts the movement of lithospheric plates.
D) the Wilson Cycle uses plate tectonic processes to describe the development of ocean basins.
E) the Wilson Cycle was named in honor of geophysicist John Tuzo Wilson.

Question 51

How has seismic activity been used in our understanding of plate boundaries?

Question 52

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

A)hydrothermal vents
B)island arc
C)mountains
D)oceanic trench
E)volcanoes

Question 53

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

A)hydrothermal vents
B)rift valley
C)oceanic ridge
D)oceanic trench
E)spreading center