OCE 1001 Chapter 2
Did any subduction occur during the collision of India and Asia?
Yes; ocean basin between these two continents subducted under Asia.
What is a volcanic arc
a row of volcanoes that forms on the overriding plate near a subduction zone
What was Pangea?
a supercontinent that formed 300 million years ago
Which of the following mountain ranges are examples of continental arcs?
andes and cascades
Which of the following is characteristic of oceanic-continental convergent plate boundaries?
andesitic volcanoes
Plates move apart at __________ boundaries, move together at __________ boundaries, and move side-by-side at __________ boundaries.
divergent/convergent/transform
Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents?
evidence of glaciers in areas that are now tropical the distribution of species of fossilsthe pattern of similar mountain belts on different continents the way the shapes of the continents fit together like pieces of a jigsaw puzzle
Which phenomenon can explain the presence of volcanoes in the middle of the Pacific Ocean?
hotspots
Coral reefs ________.
include atolls, barrier, and fringing reefs
Climate distribution on Earth is primarily controlled by:
latitude
Which geologic features are associated with divergent boundaries?
mid-ocean ridges and continental rift valleys
The Hawaiian Islands are located where the Pacific plate is:
moving over a hot spot or mantle plume
Which geologic features are associated with convergent boundaries?
ocean trenches and volcanoes
The study of historical changes of continental shapes and positions is called:
paleogeography
Fossils of ancient tropical plants are currently found near the poles because the:
plants lived in the tropics, but landmasses have drifted to current locations.
When was the Precambrian eon?
prior to 600 million years ago
Deep ocean trenches are associated with
subduction zones
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 __________.
the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket"
Based on paleogeographic records, _____________. View Available Hint(s)
the North Atlantic opened before India separated from Antarctica
Which mountain belt lies to the north of India?
the himalayas
Which plate boundary is NOT associated with volcanic eruptions?
transform
Techtonic plates move about as fast as
your fingernails grow
Where are tectonic plates located?
At earths surface
Where do earthquakes occur?
At plate boundaries
Which of the following statements about earthquakes with magnitude greater than 4.0 is most accurate?
Earthquakes with magnitude greater than 4.0 occur in a pattern than correlates closely with plate boundaries.
Which of the following is an example of an oceanic oceanic divergent plate boundary
East pacific Rise
Seafloor depth was first determined by what remote sensing technology?
Echo sounder
What are the himalayan mountains composed of
Folded and faulted rock
Why are ocean basins continually being destroyed and created, rather than simply being redistributed around Earth's surface like continents?
High-density oceanic crust subducts beneath low-density continental crust where plates converge.
Which of the following is an example of a continental-continental convergent plate boundary?
Himalaya
Which of the following tectonic plates are oceanic?
Pacific Nazca
In general, how do magnetic objects align relative to Earth's magnetic field?
Parallel
The seafloor magnetic pattern is best described as:
Parallel to and symmetric about mid-ocean ridges
Which process causes the surface geography of Earth to change over time?
Plate tectonics
"
Prior to 30 million years ago, Tibet was a much thinner landmass than it is today.
Which of the following is an example of a continental-continental divergent plate boundary?
Red sea or mendocino fault
Which of the following is an example of an oceanic transform plate boundary?
San adnreas or medocino
Which of the following is an example of a continental transform plate boundary?
San andreas
Which of the following is an example of an oceanic-oceanic convergent plate boundary?
San andreas fault or aleutian island
Where do magnetic field lines exit the Earth today?
South pole
Which of the following statements is true regarding tectonic plates?
Tectonic plates may include both oceanic and continental crust.
What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?
The Earth would increase in volume
What is the relationship between the crust and lithosphere?
The crust is apart of the lithosphere
What is the relationship between the crust and the lithosphere?
The crust is part of the lithosphere.
What is meant by the term plate boundary?
The edge of a plate, where two plates meet each other
What prompted the first widespread mapping of the ocean floor?
The importance of submarine warfare during World War II
Imagine two people standing at placemark A and placemark E, looking at each other across the fault. Which of the following statements correctly describes the relative motion of the land opposite each observer?
The land is moving right
Which of the following statements is true of the lithosphere?
The lithosphere is composed of the crust and the uppermost portion of the mantle.
Sea floor spreading along the axis of an oceanic ridge results in symmetrical patterns of all of the following EXCEPT ______________.
The location of subduction zones
Earth's magnetic field is similar to which of the following?
The magnetic field of a bar magnet
Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge?
The ocean floor is spreading apart and new sea floor is forming. The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. The polarity of Earth's magnetic field experiences reversals.
What happens when an oceanic plate converges with a continental plate?
The oceanic plate is subducted.
As Heezen and Tharp interpreted the ocean depth data, they identified what unusual feature that hinted at continental drift?
The oceanic ridges have a cleft, or rift, in the middle rather than a peak.
What happens when an oceanic plate meets another oceanic plate?
The older, colder oceanic plate is subducted.
Of the following statements about the age of the ocean crust, which one is true?
The oldest ocean crust is about 200 million years old and is located near an ocean trench.
Why didn't India subduct under Asia?
The two continents have similar densities
What happens when a continental plate meets another continental plate?
The two plates are forced upward, and a large mountain range is formed.
What did the maps of the ocean floor produced by Bruce Heezen and Marie Tharp reveal about seafloor topography
There are ridges in the middle of the ocean bases
Why did Heezen and Tharp have to do "inspired guessing" when creating their maps of the ocean floor?
There were gaps in the data
What do all plate boundaries have in common?
They are all associated with zones of earthquakes
Of the following statements about sea floor magnetic anomalies, which is true?
They are oriented parallel to the mid-ocean ridge.
What did the continents that formed during the break-up of the supercontinent 600 million years ago look like?
They were nothing like the continent shapes we see on Earth today
Where would the north end of a magnet point during a time of reverse polarity?
Toward the magnetic south pole
Which of the following is characteristic of continental-continental convergent plate boundaries?
Uplifted mountain ranges
Which of the following is characteristic of oceanic-oceanic convergent plate boundaries?
Volcanic island args
To find the largest area of the ocean with the oldest ocean crust, you should go to the ________.
Western pacific
Recent data indicate that at the time the offset of Wallace Creek began 13,000 years ago, it flowed through the valley indicated by placemark D, and only more recently did it cut its present channel into the land on the western side of the fault. Determine the average annual displacement, in inches, along this section of the San Andreas Fault. You can check your results with those published in the Field Trip Guide linked in placemark A.
1.2 " per year
Look carefully at the course of Wallace Creek. Assuming that at one time it flowed straight across the San Andreas Fault, determine the relative motion of the fault. Then use the ruler tool to determine the current offset, in feet, of Wallace Creek where it crosses the San Andreas Fault. On which of the following diagrams is the relative motion of the fault and the displacement distance labeled correctly? Pay attention to the boxed arrows on the left side of the diagrams.
430 Right left
When did the Appalachian Mountains of North America begin to form?
450 millio
When did the great mountain ranges of southern Europe and Asia begin to form?
50 million
On average, how long do periods of reverse and normal polarity last?
500,000 years
Which statement is most accurate
A moving India collided with a stationary Asia about 30 million years ago
What is a volcanic arc?
A row of volcanoes that forms on the overriding plate near a subduction zone
Evidence shows that periodic reversals of Earth's magnetic field have resulted in
A symmetrical patterns of normal and reverse magnetization in ocean crustal rocks
Which of the following mountain ranges are examples of continental arcs?
Andes and Cascades
Which type of plate boundary exists between India and Asia today?
Convergent boundary
What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?
Earth would increase in volume.
How are Earth's geographic and magnetic axes oriented relative to each other?
Earth's geographic and magnetic axes are oriented at a slight angle to each other.
Which geographic examples below result(s) from ocean-ocean convergence?
Japan Marianas Trench Aleutian islands
Consider the geologic fate of the following seamounts and islands in the Hawaiian Island-Emperor Seamount chain. Assuming conditions remain favorable for coral growth, which would most likely be the next to form an atoll?
Kauai
Tectonic plates are pieces of the ________ that float on the more fluid ________ below.
Lithosphere; athenosphere
What piece of evidence supports Wegener's hypothesis of continental drift?
Modern-day species that evolved in isolation share a common ancestor.
Complete this statement: Divergence is to moving away as convergence is to _______.
Moving toward
Of the following statements about Earth's magnetic field, which is/are true? Choose all that apply.
Not magnetic north is at the
Which geologic features are associated with convergent boundaries?
Ocean trenches and volcanoes
What did the surface of Earth look like 600 million years ago?
One continent w ocean
Where is the youngest ocean floor found?
along the crest of mid-ocean ridges
Which of the following is an example of an oceanic-continental convergent plate boundary?
andes
Which of the following features are found at an oceanic-continental convergent plate boundary?
continental arc trench Mountain
Which type of plate boundary is most closely associated with uplifting continental regions and mountain building?
convergent boundaries
The Mid-Atlantic Ridge is an example of a:
divergent plate boundary
What are the three types of plate boundaries?
divergent, convergent, and transform
Plates move apart at __________ boundaries, move together at __________ boundaries, and move side by side at __________ boundaries.
divergent/convergent/transform
