Wegener's idea that the continents slowly moved over Earth's surface became known as
What is continental drift
100
long chains of mountains that rise up from the ocean floor
What is mid ocean ridges
100
What evidence supports the theory of sea floor spreading
What is eruption of molten material that forms pillow lava along ridges, magnetic stripes, and the increasing age of oceanic crust away from the ridge.
100
What part of the Earth is broken into pieces separated by cracks called plates
What is lithosphere
100
How do plates move?
What is slow and in all directions
200
continents were joined together in a supercontinent, or single landmass called
What is Pagnaea
200
a device that uses sound waves to measure the distance to an object.
What is sonar
200
the oceanic crust bends downward, it takes tens of millions of years, part of the ocean floor sinks back into the mantle at
What is deep ocean trenches
200
Plates can move in how many directions?
What is three
200
Earth's plates move because they are the top part of the large _________ ____________in Earth's mantle.
What is convection currents
300
any trace of an ancient organism that has been preserved in rock
What is a fossil?
300
mid ocean ridges continually add new material to the ocean floor called
What is sea floor spreading
300
the process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle again
What is subduction
300
Plates move apart from each other called
What is divergent boundary?
300
the edges of Earth's plates meet at plate boundaries. These are breaks in Earth's crust where rocks have slipped past each other.
What is a fault?
400
Wegener used evidence of fossils and ______to support his hypothesis. As a continent moves toward the equator, it _______get warmer. As a continent moves toward the poles, its _________get colder.
What is climate
400
sea floor spreading begins at a _______________, which forms along a crack in the oceanic crust
What is mid - ocean ridge?
400
these two processes work together and can change the size and shape of the oceans
What is subduction and sea floor spreading
400
Plates come together called
What is convergent boundary
400
Where pieces of Earth's crust diverge on land, a deep valley called a
What is rift valley
500
Wegner attempted to explain how continental drift took place. He suggested that the continents plowed across the ocean floors. Wegener could not identify the cause of continental drift, most geologists of his time ________his idea.
What is rejected!
500
Sea floor spreading adds more ______to the ocean floor. At the same time, older strips of rock move outward from either side of the ridge.
What is crust
500
The sizes of Earth's oceans are determined by how fast new crust is being created at _________________and how fast old crust is being swallowed up at _____________________
What is mid - ocean ridges and deep ocean trenches
500
Plates slip past each other along
What is transform boundary
500
What occurs along the mid-ocean ridge, where new crust is added during sea floor spreading