Continental Drift Flashcards
True or False - Some early mapmakers thought that the coastline of South America matched the coastline of Asia. ____
False
True or False - Scientists at the time rejected Wegener’s hypothesis of continental drift because he could not explain how or why Earth’s continents move.
True_
True or False - As new seafloor moves away from an ocean ridge, the seafloor cools and becomes less dense than the material beneath it.
False
True or False - According to the theory of plate tectonics, plates interact at plate boundaries by deflecting each other, moving away from each other, or moving horizontally past each other
False
True or False - If two continental plates converge, a subduction zone forms.
False
True or False - The transfer of thermal energy by the movement of warmed matter is called convection
True_
True or False - The rising part of a convection current causes both upward and lateral forces that lift and split the lithosphere at a divergent boundary.
True
True or False - The weight of a subducting plate helps to pull the plate into a subduction zone in a process called ridge push.
False
The existence of coal beds in Antarctica indicates that the continent once was____.
closer to the equator
____ is a fossil fern that helped support Wegener’s hypothesis of continental drift.
Glossopteris
The youngest part of the ocean floor is found ____.
near ocean ridges
At an oceanic-oceanic convergent boundary, ____.
old crust is recycled by subduction
Convection currents transfer thermal energy ____.
from warmer regions to cooler regions
The downward part of a convection current causes a sinking force that ____.
pulls tectonic plates toward one another
Many early mapmakers thought Earth’s continents had moved based on ____.
matching coastlines
Continental drift was not widely accepted when it was first proposed because ____.
Wegener couldn’t explain why or how the continents moved
Compared to ocean crust near deep-sea trenches, crust near ocean ridges is ____.
a.
younger
The magnetic pattern of ocean-floor rocks on one side of an ocean ridge is ____.
a mirror image of that of the other side
Isochron maps of the seafloor indicate that ocean crust is ____.
youngest near ocean ridges
Each cycle of spreading and intrusion of magma during seafloor spreading results in ____
new ocean crust
Features found at divergent boundaries include ____.
ocean ridges
Continental-continental plate collisions produce ____.
very tall mountain ranges
Crust is neither destroyed nor formed along which of the following boundaries?
transform
One of the driving forces of tectonic plates are related to convection currents in Earth’s ____.
mantle
A vast, underwater mountain chain forms at a(n) _________.
ocean ridge
A narrow, elongated depression in the seafloor is called a(n) _________.
deep-sea trench
____________ is defined as the study of the history of earth’s magnetic field.
paleomagnetism
A landmass comprised of all of Earth’s continents
Pangea
A device that measures changes in Earth’s magnetic field
magnetometer
A narrow, elongated depression in the seafloor
deep sea trench
A narrow, long depression in continental crust
rift valley
Type of boundary characterized by long faults and shallow earthquakes
transform
Theory that states that Earth’s crust and upper mantle are broken into enormous slabs
plate tectonics
The mechanisms thought to be associated with plate movements
convection currents
The process that helps to move an oceanic plate toward a subduction zone
ridge push
