oce1001 chpt 2

t

A rift valley may be associated with divergent plate boundaries. (t/f)

a

As Heezen and Tharp interpreted the ocean depth data, they identified what unusual feature that hinted at continental drift? a) The oceanic ridges have a cleft, or rift, in the middle rather than a peak. b) The oceanic ridges have a broad, flat top very much resembling a table top. c) Ocean ridges are unique to the Pacific Ocean. d) They discovered a chain of very tall volcanoes in the middle of the Atlantic Ocean that do not rise higher than the sea surface. e) Ocean ridges abruptly stop after a few hundred kilometers and then start again after a few hundred more.

continental crust

Australia is composed of relatively old and thick

e

Based on paleogeographic records, _____________. a) the continents came together as Pangaea before North America was located at the equator b) India separated from Antarctica before the continents came together as Pangaea c) the North Atlantic opened before North America was located at the equator d) India separated from Antarctica before North America was located at the equator e) the North Atlantic opened before India separated from Antarctica

latitude

Climate distribution on Earth is primarily controlled by:

c

Compared to the rest of the planet, an unusually high concentration of hot spots and rifting is located on the continent of Africa. A likely explanation for this is that __________. a) a large portion of Africa is located near the equator b) mantle plumes do not occur at divergent plate boundaries, and Africa has no divergent plate boundaries c) the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket" d) the thick continental crust acts as a "heat blanket" and a large portion of Africa is located near the equator e) Africa is just very large

fringing reefs

Coral reefs that initially develop along the margin of an island or continent where environmental conditions are suitable are called:

t

Deep-sea trenches are found at convergent plate boundaries. (t/f)

b

Do fracture zones near transform boundaries play a role in plate motion? a) Yes; fracture zones mark areas where plates are moving toward each other. b) No; fracture zones play no role in plate motion. c) Yes; fracture zones mark areas where plates are moving away from each other. d) Yes; fracture zones mark areas where plates are moving past each other.

c

Evaluate these statements and determine the evolutionary stage of an ocean basin based upon the following characteristics: Lacks a mid-ocean ridge Deep ocean basin is present Early signs of mountain formation Volcanic island arc and trench absent a) suturing b) mature c) terminal d) juvenile e) declining

a

How are continental rift magmas and continental arc magmas different? a) Continental arc magmas are more viscous than continental rift magmas. b) Continental arc magmas are less viscous than continental rift magmas. c) Continental arc magmas are less dangerous than continental rift magmas. d) Continental arc magmas are more dangerous than continental rift magmas.

d

How are island arc and continental arc magmas similar? a) Both are formed near spreading centers. b) Both are formed near hot spots. c) Both are formed near transform boundaries. d) Both are formed near subduction zones.

d

How do plates move at convergent plate boundaries? a) Plates slide past one another. b) Plates move apart. c) Plates do not move. d) Plates move toward one another.

a

How do plates move at divergent plate boundaries? a) Plates move apart. b) Plates move toward one another. c) Plates do not move. d) Plates slide past one another.

d

How do plates move at transform plate boundaries? a) Plates move apart. b) Plates move toward one another. c) Plates do not move. d) Plates slide past one another

divergent

Iceland is located on what type of plate boundary?

2000 km

If ocean crust forms at a rate of 10 centimeters per year, how much ocean crust can be created in 20 million years?

a,c

In general, where do earthquakes AND volcanic eruptions occur? Choose all that apply. a) divergent plate boundaries b) away from plate boundaries c) convergent plate boundaries d) transform plate boundaries

b

In general, where do volcanoes form in subduction zones? a) on the subducting plate, at the convergent boundary b) on the overriding plate, away form the convergent boundary c) on the subducting plate, away form the convergent boundary d) on the overriding plate, at the convergent boundary

north

In which direction is the plate moving at point A?

south

In which direction is the plate moving at point B?

south

In which direction is the plate moving at point C?

seamounts

Large volcanoes on the seafloor that are cone-shaped on top because they never reached sea level are called

sedimentary rock

Layered _________________ exposed by erosion can be seen when looking at the Grand Canyon in the United States.

a

Match the term with the appropriate phrase. mid-ocean ridge a) spreading center b) subduction zone

b

Match the term with the appropriate phrase. trench a) spreading center b) subduction zone

a

Moving from an oceanic ridge to an oceanic trench, the thickness of the lithosphere: a) increases in proportion to the distance. b) randomly varies. c) remains the same. d) is unrelated to the distance from the ridge. e) decreases in proportion to the distance.

all

Of the following statements about nemataths and volcanic arcs, which is/are true? Nemataths and volcanic arcs are both the result of volcanic activity. In a volcanic arc, any of the volcanoes can be active at any time. A volcanic arc is associated with a convergent plate boundary. A nematath is created by a hotspot. In a nematath, the age of the volcanoes progressively decreases as you move closer to the volcanic source.

d,f

Of the following statements about ocean crust, which is/are true? a) Ocean crust is destroyed at transform faults. b) Ocean crust is destroyed at the mid-ocean ridge. c) Ocean crust is created at deep sea trenches. d) Ocean crust is created at the mid-ocean ridge. e) Ocean crust is created at transform faults. f) Ocean crust is destroyed at deep sea trenches.

hot spot

Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a

f

Paleomagnetism confirms that at particular times in the geologic past Earth has had more than one magnetic north pole (t/f)

e

Sea floor spreading along the axis of an oceanic ridge results in symmetrical patterns of all of the following EXCEPT ______________. a) the age of the sea floor b) the depth of the sea floor c) the paleomagnetic record d) the flow of heat through the crust e) the location of subduction zones

echo sounder

Seafloor depth was first determined by what remote sensing technology?

b

Tectonic plates are pieces of the ________ that float on the more fluid ________ below. a) asthenosphere; lithosphere b) lithosphere; asthenosphere c) lithosphere; mesosphere d) mantle; crust e) crust; lithosphere

d

The East African rift is a divergent plate boundary that is splitting the continent of Africa into two pieces. What will eventually form around this divergent boundary? a) a continent b) a convergent boundary c) a transform boundary d) an ocean e) a hurricane

a

The Mid-Atlantic Ridge is an example of a: a) divergent plate boundary. b) convergent plate boundary (continent-continent). c) transform fault boundary. d) convergent plate boundary (oceanic-oceanic). e) convergent plate boundary (continent-oceanic).

fault

The earthquakes that occur in Southern California generally occur above a

subduction

The extremely deep ocean Marianas Trench is a result of

alfred wegener

The first person to advance the idea of mobile continents or continental drift was:

f

The majority of the world's hotspots are associated with plate boundaries. (t/f)

t

The relatively young age of the seafloor supports the idea that subduction must take place (t/f)

d

The seafloor magnetic pattern is best described as: a) parallel to, but not symmetric about mid-ocean ridges. b) perpendicular to, but not symmetric about mid-ocean ridges. c) perpendicular to and symmetric about mid-ocean ridges. d) parallel to and symmetric about mid-ocean ridges. e) not related to the location of mid-ocean ridges.

seafloor spreading

The slowly increasing distance between South America and Africa is due to

paleogeography

The study of historical changes of continental shapes and positions is called:

c

Transform boundaries are classified under what type of fault? a) reverse b) normal c) strike-slip

e

Wegener used all the following to provide evidence for continental drift except : a) age of selected continental rocks. b) shape of continental margins. c) location of coral reef fossils. d) apparent polar wandering. e) seafloor magnetic pattern.

the collision of India with Asia

What caused the formation of the Himalayas?

e

What did the maps of the ocean floor produced by Bruce Heezen and Marie Tharp reveal about seafloor topography? a) Ocean basins are very flat features. b) There are ridges near the edges of the oceans, a few hundred miles from the edges of each of the continents. c) The seafloor data revealed that the middle of oceans is where continents appear to be drifting toward each other. d) Ocean floors and continental areas are morphologically very similar to each other. e) There are ridges in the middle of the ocean basin floors.

b

What forms at divergent plate boundaries? a)new continental lithosphere b) new oceanic lithosphere

a

What is a seamount? a) An active volcano that occurs along the crest of the mid-ocean ridge. b) An active volcano that occurs along the trench of a subduction zone. c) An inactive volcano that occurs along the crest of the mid-ocean ridge. d) An inactive volcano that occurs along the trench of a subduction zone.

d

What is a tablemount? a) A seamount that grew to just below sea level, experienced wave erosion, and is now inactive. b) A seamount that grew above sea level, experienced wave erosion, and is now active. c) A seamount that grew to just below sea level, experienced wave erosion, and is now active. d) A seamount that grew above sea level, experienced wave erosion, and is now inactive.

convection

What is the appropriate term for the movement of the orange liquid in the lava lamp animation?

a

What is the difference between a barrier reef and an atoll? a) Barrier reefs surround an inactive volcano emerging above sea level, while atolls surround the previous location of a submerged volcano. b) Atolls surround an inactive volcano emerging above sea level, while barrier reefs surround the previous location of a submerged volcano. c) Barrier reefs surround an active volcano emerging above sea level, while atolls surround the previous location of a submerged volcano. d) Atolls surround an active volcano emerging above sea level, while barrier reefs surround the previous location of a submerged volcano.

d

What is the relationship between continent edges and plate boundaries? a) No plate boundaries follow the edges of continents. b) Most plate boundaries follow the edges of continents. c) Almost all plate boundaries follow the edges of continents. d) Very few plate boundaries follow the edges of continents.

d

What is the relationship between transform boundaries and mid-ocean ridges? a) Transform boundaries move segments of mid-ocean ridges. b) Transform boundaries destroy segments of mid-ocean ridges. c) Transform boundaries create segments of mid-ocean ridges. d) Transform boundaries connect segments of mid-ocean ridges.

c

What prompted the first widespread mapping of the ocean floor? a) The sinking of the Titanic b) he creation of NASA c) The importance of submarine warfare during World War II d) The laying of undersea telegraph lines between the United States and Europe e) Conflicts over maritime (ocean) territorial claims during the 1970s

c

What role do transform boundaries play? a) Transform boundaries create other segments of plate boundaries. b) Transform boundaries replace other segments of plate boundaries. c) Transform boundaries connect other segments of plate boundaries. d) Transform boundaries destroy other segments of plate boundaries.

not a plate boundary

What type of boundary is represented by the line just to the east of point A?

b

What were the names of the two smaller super continents that formed when Pangaea broke apart? a) Laurasia and Pangaea Minor b) Laurasia and Gondwanaland c) Pangaea Major and Pangaea Minor d) Pangaea Major and Gondwanaland e) Pangaea Major and Laurasia

d

What would happen in the lava lamp if the orange liquid were denser at warmer temperatures than the blue/clear liquid shown in the animation? a) Both the orange and the blue/clear liquids would rise toward the top when the lamp was turned on. b) Both the orange and the blue/clear liquids would stay near the bottom when the lamp was turned on. c) The orange liquid would rise toward the top when the lamp was turned on, whereas the blue/clear liquid would sink. d) The blue/clear liquid would rise toward the top when the lamp was turned on, whereas the orange liquid would sink.

c

What would happen to the orange liquid in the lava lamp if heat did NOT conduct out of the top of the lava lamp? a) The orange liquid would rise toward the top of the lava lamp. b) The orange liquid would stay near the bottom of the lava lamp. c) The orange liquid would stay near the top of the lava lamp. d) The orange liquid would sink toward the bottom of the lava lamp.

a

Where are continental volcanic arcs found? a) on the overriding plate near a subduction zone b) on the overriding plate near a mid-ocean ridge c) on the downgoing plate near a subduction zone d) on the downgoing plate near a mid-ocean ridge

b

Where do coral reefs exist with sea mounts? a) In polar latitudes b) In tropical latitudes c) In both polar and tropical latitudes

d

Where does the water involved in melting at subduction zones come from? a) Water from the ocean is pulled down by the subducting plate and is released during metamorphism. b) Water contained within minerals in the overriding plate is released during metamorphism. c) Water from the ocean is pulled down by the subducting plate, is absorbed into minerals, and is released during metamorphism. d) Water contained within minerals in the subducting plate is released during metamorphism.

c

Where in a lava lamp would the density of both materials be equal? a) almost everywhere in the lamp b) near the bottom of the lamp c) near the middle of the lamp d) near the top of the lamp e) nowhere in the lamp

c

Which hypothesis best explains the continuous bend in the Hawaiian Islands-Emperor Seamount chain? a) The trench associated with the formation of this feature has a continuous bend in it. b) This feature results from two independent mantle plumes that merged to create the appearance of a bend. c) The direction of plate motion shifted over time over a stationary mantle plume (hot spot). d) The location of the mantle plume that formed this feature drifted over time. e) The mid-ocean ridge that forms this feature has a continuous bend in it.

d

Which is the correct order of coral reef development near seamounts? a) Barrier reef, fringing reef, atoll b) Atoll, fringing reef, barrier reef c) Barrier reef, atoll, fringing reef d) Fringing reef, barrier reef, atoll e) Fringing reef, atoll, barrier reef

a,b,c,e

Which of the following are common tectonic settings associated with volcanic activity? CHOOSE ALL THAT APPLY. a) continental rifts b) mantle plumes c) continental arcs d) transform plumes e) island arcs

c,d

Which of the following are examples of modern-day island arcs? CHOOSE ALL THAT APPLY. a) Hawaiian Islands b) East African rift c) Mariana Islands d) Aleutian Islands

c,d,e

Which of the following could cause rock to melt? CHOOSE ALL THAT APPLY a) decrease in temperature b) increase in pressure c) decrease in pressure d) increase in temperature e) change in composition

d

Which of the following is a present-day example of a continental rift? a) the West African rift valley b) the North American rift valley c) the South American rift valley d) the East African rift valley

Hawaii

Which of the following is an example of modern-day mantle plume volcanism?

c

Which of the following is characteristic of continental-continental convergent plate boundaries? a) volcanic island arcs b) mid-ocean ridges c) uplifted mountain ranges d) hot spots

a

Which of the following is characteristic of oceanic-oceanic convergent plate boundaries? a) volcanic island arcs b) mid-ocean ridges c) fracture zones d) hot spots

a,b,d,e

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? a) the distribution of species of fossils b) the way the shapes of the continents fit together like pieces of a jigsaw puzzle c) the composition of meteors from outer space d) the pattern of similar mountain belts on different continents e) evidence of glaciers in areas that are now tropical

e

Which of the following often forms after continental rifting? a) a new continent b) a new mountain c) a transform boundary d) a subduction zone e) a new ocean basin

c

Which of the following statements about coral reefs and seamounts is most accurate? a) Seamounts at the ocean surface grow away from coral reefs over time. b) Seamounts at the ocean surface grow towards coral reefs over time. c) Coral reefs at the ocean surface grow away from seamounts over time. d) Coral reefs at the ocean surface grow towards seamounts over time.

c

Which of the following statements about tectonic plates is true? a) Few tectonic plates contain both oceanic and continental lithosphere. b) All tectonic plates contain both oceanic and continental lithosphere. c) Most tectonic plates contain both oceanic and continental lithosphere. d) No tectonic plates contain both oceanic and continental lithosphere.

b

Which properties of a lava lamp are important to remember when modeling convection? a) The lava lamp contains three liquids with similar densities that do not mix and that expand at similar rates when heated. b) The lava lamp contains two liquids with different densities that do not mix and that expand at different rates when heated. c) The lava lamp contains two liquids with similar densities that do not mix and that expand at similar rates when heated. d) The lava lamp contains three liquids with different densities that do not mix and that expand at different rates when heated.

Gondwanaland

Which supercontinent contained Africa and South America?

b

Which two processes commonly generate magma? a) decompression melting and dry melting b) decompression melting and wet melting (the addition of volatiles) c) compression melting and wet melting (the addition of volatiles) d) compression melting and dry melting

c

Why are volcanoes NOT found at transform boundaries? a) Transform boundaries cause increases in temperature that exactly offset decreases in pressure of the mantle. b) Transform boundaries cause changes to the pressure, temperature, or composition of the mantle. c) Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle. d) Transform boundaries cause decreases in temperature that exactly offset increases in pressure of the mantle.

e

Why did Heezen and Tharp have to do "inspired guessing" when creating their maps of the ocean floor? a) They were limited by the mapping technology of the time. b) The data they used came from tracks of ships that overlapped each other. c) Data could not be collected for parts of the ocean that were greater than 10,000 feet deep. d) They were given only a small portion of the depth data by the Navy. The rest was classified. e) There were gaps in the data that were used to make the map because the tracks of the ships collecting the data were widely spaced.

b

Why do coral reefs at the ocean surface grow away from seamounts over time? a) Seamounts uplift as tectonic plates move. Coral reefs grow away from the seamount in order to stay in the ocean water. b) Seamounts subside as tectonic plates move. Coral reefs grow away from the seamount in order to stay near the sunlight. c) Seamounts subside as tectonic plates move. Coral reefs grow away from the seamount in order to stay in the ocean water. d) Seamounts uplift as tectonic plates move. Coral reefs grow away from the seamount in order to stay near the sunlight.

a

Why does the orange liquid rise when the lava lamp animation is plugged in? a) Although both liquids expand when heated, the orange liquid expands more. b) Although both liquids expand when heated, the orange liquid expands less. c) The orange liquid expands, whereas the other liquid does not. d) The orange liquid does not expand, whereas the other liquid does.

b,c,d

Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge? a) The reversals occur as existing ocean crust is remagnetized during reversals. b) The ocean floor is spreading apart, and new sea floor is forming. c) The polarity of Earth's magnetic field experiences reversals. d) The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. e) Marine organisms that live on the sea floor have caused this pattern.

b

Why is decompression melting common at mid-ocean ridges but not at subduction zones? a) Tectonic plates are moving apart at mid-ocean ridges, resulting in an increase of pressure beneath the ridge. Tectonic plates are moving together at subduction zones, resulting in a lowering of pressure under new mountains. b) Tectonic plates are moving apart at mid-ocean ridges, resulting in a lowering of pressure beneath the ridge. Tectonic plates are moving together at subduction zones, resulting in an increase of pressure under new mountains. c) Tectonic plates are moving together at mid-ocean ridges, resulting in an increase of pressure beneath the ridge. Tectonic plates are moving apart at subduction zones, resulting in a lowering of pressure under new mountains. d) Tectonic plates are moving together at mid-ocean ridges, resulting in a lowering of pressure beneath the ridge. Tectonic plates are moving apart at subduction zones, resulting in an increase of pressure under new mountains.

c

Why is water a necessary component of the melting process in subduction zones? a) The addition of water lowers the friction experienced by rising magma. b) Water is a liquid, and rock needs to encounter a liquid in order to become a liquid. c) The addition of water lowers the melting temperature of rock. d) Water creates a buoyant force that allows the magma to rise. e) Water changes the density of the rock, allowing the rock to melt.

seafloor crust

_________ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.

mantle plume

a circular column of magma that rises from deep within Earth

tethys sea

a piece of the Panthalassa Ocean that existed after the Pangaean supercontinent formed

pangaea

a supercontinent that began to break apart about 200 million years ago

paleomagnetism

study of magnetism over geologic time

peridotite

the rock making up the mantle is called

panthalassa

the single ocean that existed after the Pangaean supercontinent formed

A

what phrase does not fit A. hydrothermal vents B. island arcs C. tall, folded mountain belts D. oceanic trenches E. large volcanoes caused by subduction

E

what phrase does not fit A. transform fault B. San Andreas Fault C. oceanic transform fault D. Mendocino Fracture Zone E. Mariana Trench