question

A(n)____ occurs where two plates converge, and the denser plate is subducted

answer

Oceanic-continental convergence

question

A(n) ____ occurs where two plates of the same composition converge, resulting in the older, denser plate being subducted

answer

Oceanic-oceanic convergence

question

A(n) ____ occurs where two plates of the same composition converge, resulting in neither plate being subducted

answer

Continental-continental convergence

question

India seperated from Antartica _____

answer

120 mya

question

The North Atlantic Ocean opened _____

answer

180 mya

question

The continents came together as Pangaea ______

answer

300 mya

question

North America lay on the equator ________

answer

540 mya

question

Which type of plate boundary is most closely associated with the formation of new ocean floor?

answer

divergent

question

Which of the following statements about Earth's magnetic field is most accurate?

answer

Earth's magentic field switches polarity at irregular time intervals

question

How often does the Earth's magnetic field switch polarity

answer

every 100,000 to several million years

question

How are normal polarity and reverse polarity of Earth's magnetic field different?

answer

A compass points towards the North Pole during normal polarity and the South Pole during reverse polarity

question

In general, what is our best evidence that the orientation of Earth's magentic field has changed over time?

answer

A record of Earth's magnetic field is recorded in oceanic rocks, which shows a clear pattern of changes in Earth's magnetic field

question

Where would you expect to see alternating bands of rock with different magnetic polarities

answer

on both sounds of the mid-ocean ridge

question

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

answer

Seafloor spreading

question

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

answer

hot spot

question

Layered ____ exposed by erosion can be seen when looking at the Grand Caynon in the United States

answer

sedimentary rock

question

Australia is composed of relatively old and thick

answer

continental crust

question

The extremely deep ocean Mariana's Trench is a result of

answer

subduction

question

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

answer

Seafloor crust

question

The earthquakes that occur in Southern California generally occur above a

answer

fault

question

Evidence for continental drift includes:

answer

The distribution of organisms, matching sequences of rocks and mountain chains, past glacial activity, and the fit of the continents

question

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

answer

plants lived near the poles, but landmases have drifted to current locations

question

Climate distribution on Earth is primarily controlled by

answer

latitude

question

Regarding glacial ages, why is it unlikely that the entire world was covered by ice 300 mya?

answer

Coal deposits from the same geological age are now present in North America and Europe, which formed the remains of vast tropical swamps

question

Earthquakes can only occur in the ______

answer

lithosphere

question

The seafloor magnetic pattern is best described as

answer

parallel to and symetric about mid ocean ridges

question

Tectonic plates are pieces of the ________ that float on the more fluid ________ below

answer

lithosphere; asthenosphere

question

Describe seafloor spreading and why it is an important piece of evidence in support of plate tectonics

answer

Captain Hess suggested that new ocean crust was created at the mid-oceanic ridges and dispearred back into deep Earth at the trenches near the edge of ocean basins. This was an important piece of evidence in support of plate tectonics because it provided a mechanism for continental and oceanic plate motion

question

When will magnma rise to the Earth's surface?

answer

when the magma is less dense than adjacent rock

question

In general, when will melted rock in the mantle rise?

answer

almost always

question

How are felsic magmas formed?

answer

Heat from the mantle melts part of the lower crust

question

In general, why does Earth's crust sit on top of the mantle?

answer

earth's crust is less dense than the mantle

question

How do mafic volcanic rocks get to Earth's surface?

answer

Pressure from overlying crust forces mantle magmas through cracks to Earth's surface. These magmas erupt out of volcanoes, cool and solidy into rock1

question

Where are tectonic plates located?

answer

At Earth's surface

question

What are the three types of plate boundaries?

answer

Divergent, convergent and transform

question

Which of the following statements about earthquakes with magnitude greater than 4.0 is most accurate?

answer

Earthquake with a magnitude greater than a 4.0 occur in a pattern that correlates closely with plate boundaries

question

Which plate boundary is NOT associated with volcanic eruptions?

answer

Transform

question

Which phenomenon can explain the presence of volcanoes in the middle of the Pacific Ocean?

answer

hotspots

question

Which type of plate boundary is most closely associated with uplifting continental regions and mountain building?

answer

Convergent boundaries

question

What is convection

answer

A cycle of moving material formed by the rise of less-dense material and sinking of denser material

question

What is responsible for most tectonic plate action?

answer

Forces at subduction zones

question

What is the relationship between temperature and denisty?

answer

In general, warmer materials are less dense and colder materials are denser

question

Which of the following best characterizes upwelling in the asthenosphere

answer

diffuse

question

What is a plume

answer

a zone of upwelling material originating at the outer-core mantle boundary

question

What features at the surfaces provide evidence of plumes?

answer

Hot spots

question

Which of the following are types of volcanoes?

answer

Cinder cone, shield volcano, composite volcano

question

What information do geologists use to classify volcanoes?

answer

shape and type of deposits

question

Cinder cones are made of________.

answer

Pyroclastic deposits

question

In general, how often do most cinder cones erupt?

answer

once

question

What are shield volcanoes generally made of?

answer

Basalt flows

question

What is the range of shield volcano height?

answer

300 to 10000 m

question

What are composite volcanoes made of?

answer

Basalt flows, pryroclastic volcanos

question

Why are shield volcanoes wider than composite volcanoes?

answer

The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes.

question

What type of volcanoes are the highest?

answer

Shield volcanoes

question

What is the range of dome complex height?

answer

500 to 2000 m

question

The Mid Atlantic Ridge is an example of a

answer

divergent plate boundary

question

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

answer

andesitic volcanoes

question

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

answer

uplifted mountain ranges

question

Deep-sea trenches are found at convergent plate boundaries

answer

True

question

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

answer

False

question

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

answer

False

question

Do most lithospheric plates contain both oceanic- and continental-type crust?

answer

Yes, most contain both oceanic and contintenal type crust

question

What is the relationship between the crust and the lithosphere?

answer

All of the crust is contained within a larger layer called the lithosphere

question

What is the relationship between the mantle and the lithosphere?

answer

Some of the mantle is contained within a smaller layer called the lithosphere

question

What is the relationship between the mantle and the asthenosphere?

answer

All of the asthenosphere is contained within a larger layer called the mantle

question

What surface feature provides evidence for the location of hot spots?

answer

Volcanoes within tectonic plates

question

When will a hot spot volcano become extinct?

answer

When the volcano is carried away from the hot spot by the tectonic plate

question

What surface feature would you expect to form if both a hot spot and a tectonic plate are stationary?

answer

A single volcano

question

What is a seamount

answer

An active volcano that occurs along the crest of the mid ocean ridge

question

What is a tablemount

answer

A seamount that grew above sea level, experienced wave erosion and is now inactive

question

Where do coarl reefs exist within seamounts

answer

In tropical latitudes

question

Which of the following statements about coral reefs and seamounts is most accurate?

answer

Coral reefs at the ocean surface grow away from seamouts overtime

question

Why do coral reefs grow away from seamounts over time?

answer

Seamounts subside as tectonic plates move. Coral reefs grow away from the seamounts in order to stay near the sunlight

question

What is the difference between a barrier reef and an atoll?

answer

Barrier reefs surround an inactive volcano emerging above sea level, while atolls surround the previous location of a submerged volcano.

question

Which is the correct order of coral reef development near seamounts?

answer

Fringing reef, barrier reef, atoll

question

Iceland is located on what type of plate boundaray

answer

Divergent

question

The Hawaiian Islands are located where the Pacific plate is:

answer

Moving over a hot spot or mantle plume

question

volcanoes on the seafloor that are flat-topped because of wave erosion are called:

answer

tablemounts

question

The first scientist to propose the origin of coral reefs based upon subsidence (sinking) of volcanic islands was:

answer

Charles Darwin

question

Areas of intense volcanic activity that remain in more or less the same location over long periods of geologic time and are unrelated to plate boundaries are called hotspots.

answer

True

question

The majority of the world's hotspots are associated with plate boundaries.

answer

False

question

Charles Darwin was the first person to propose a hypothesis on the origin of coral reefs.

answer

True

question

How is the age distribution pattern of the Hawaiian Islands-Emperor Seamount chain explained by the position of the Hawaiian hot spot

answer

The volcanoes here get progessively odler as one heads NW from Hawaii. These age relationships suggest that the Pacific plate has been steadily moving NW, while underlying mantle plume has remained relatively stationary

question

How can plate tectonics be used to help explain the difference between a seamount and a tablemount?

answer

A seamount is a volcano with a cone-shaped top, whereas a tablemount is a volcano with a flattened top. Though both of these features originate at the crest (and topographic high) of the mid-ocean ridge, a tablemount has been subject to wave erosion when it rises above sea level. When the crust containing the tablemount is pushed away from the crest (and therefore onto a topographically lower position), or is moved away from a hot spot, it is re-submerged with its flat top

question

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

answer

paleogeography

question

Loihi is

answer

the neweste Hawaiian volcano

question

A researcher interested in the vertical zonation of oceanic lithosphere would want to study __________.

answer

Ophiolites

question

The wilson cycle uses plate tectonic processes to show the life cycle of ocean basins during their growth, formation, and destruction over gelogical time

answer

True

question

Of the following statements about Earth's magnetic field, which is/are true?

answer

The magnetic field is oriented vertical relative to Earth's surface at the south magnetic pole

question

Of the following statements about ocean crust, which is/are true

answer

Ocean crust is destroyed at deep sea trenches

question

What do all plate boundaries have in common?

answer

They are all associated with zones of Earthquakes

question

Of the following statements about nemataths and volcanic arcs, which is/are true?

answer

In a volcanic arc, any of the volcanoes can be active at any time

question

What was the main reason scientists objected to Alfred Wegners idea of continental drift?

answer

Wegener's proposed mechanism for movement was thought to violate the laws of physics

question

As a tool, the modern evidence from paleomagnetism has helped support plate tectonics by showing that

answer

magnetic sea floor "stripes" are symmetric with respect to the mid ocean ridge

question

The East Pacific ridge is associated with what type of boundary?

answer

Divergent

question

How is it that the Ocean floor is much younger than the ocean itself

answer

The ocean floor keeps regenerating itself

question

plate boundaries where new oceanic crust is being added are called

answer

divergent boundaries

question

The faster the rate of spreading at the mid ocean ridge or rise, the ____ the underwater volcanic range

answer

broader (wider)

question

Most lithospheric plates contain both oceanic and continental crust

answer

True

question

The Hawaiian islands are associated with which type of plate boundary

answer

they are not associated with any type of plate boundary

question

In general, where would the youngest ocean floor be found

answer

at the mid ocean ridge

question

What happens when an oceanic and continental plate converge>

answer

The oceanic plate will be subducted

question

What happens when two continental plates conver

answer

Neither subducts; instead a mntn range forms

question

Your job is to locate the worlds plate boundaries. To do this you may use only one map. The best map to choose for this job is a map that shows the worldwide locations of

answer

earthquakes

question

Which of the following is associated with a subduction zone

answer

a volcanic arc

question

How much wider is the Atlantic Ocean today than when Christopher Columbus sailed? Assume that the Atlantic Ocean is getting wider at a rate of 3 centimeters per year (about 1 inch). (Round off the dates to the nearest century to make the calculation simpler.)

answer

15 m (49 ft)

question

An ocean trench is what type of boundary

answer

convergent

question

The San Andreas Fault is associated with which type of plate boundary?

answer

transform

question

Where would you not expect to find significant volcano activity

answer

continental collision zones

question

Which of the following tropical islands would likely be the youngest?

answer

Tropical island with a fringing reef

question

What best describes the tectonic setting of the Cascade mtns of the Pacific NW

answer

subduction zone

question

Overall the Atlantic Ocean is ____ and the Pacific is _____

answer

growing; shrinking

OCE1001 ch 2 – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards