Plates Shape Continents - Middle School Earth and Space Science
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Which coastline fit is the classic example used to support continental drift?
Which coastline fit is the classic example used to support continental drift?
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South America and Africa. Their eastern and western coastlines fit remarkably well when joined.
South America and Africa. Their eastern and western coastlines fit remarkably well when joined.
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What is seafloor spreading?
What is seafloor spreading?
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Creation and outward movement of oceanic crust from ridges. Process where new ocean floor forms and pushes older crust away.
Creation and outward movement of oceanic crust from ridges. Process where new ocean floor forms and pushes older crust away.
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Which seafloor feature is a deep, narrow depression commonly found at convergent boundaries?
Which seafloor feature is a deep, narrow depression commonly found at convergent boundaries?
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Deep-ocean trench. Forms where one oceanic plate descends beneath another.
Deep-ocean trench. Forms where one oceanic plate descends beneath another.
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What is the name of the idea that continents were once joined and later moved apart?
What is the name of the idea that continents were once joined and later moved apart?
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Continental drift. Wegener's hypothesis that continents move across Earth's surface.
Continental drift. Wegener's hypothesis that continents move across Earth's surface.
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Which statement best links continental shapes and seafloor features as evidence of plate motion?
Which statement best links continental shapes and seafloor features as evidence of plate motion?
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Continents fit together and seafloor spreads from ridges over time. Both show plates have moved from past positions.
Continents fit together and seafloor spreads from ridges over time. Both show plates have moved from past positions.
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Identify the key evidence from seafloor magnetism that shows new crust forms at ridges.
Identify the key evidence from seafloor magnetism that shows new crust forms at ridges.
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Matching magnetic stripe ages mirrored across the ridge. Symmetrical patterns prove simultaneous formation and spreading.
Matching magnetic stripe ages mirrored across the ridge. Symmetrical patterns prove simultaneous formation and spreading.
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Which boundary type is indicated by offset ridge segments and frequent shallow earthquakes?
Which boundary type is indicated by offset ridge segments and frequent shallow earthquakes?
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Transform boundary. Plates slide laterally past each other.
Transform boundary. Plates slide laterally past each other.
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Which boundary type is indicated by an ocean trench: divergent, convergent, or transform?
Which boundary type is indicated by an ocean trench: divergent, convergent, or transform?
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Convergent boundary. Plates collide and one descends beneath the other.
Convergent boundary. Plates collide and one descends beneath the other.
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Which boundary type is indicated by a mid-ocean ridge: divergent, convergent, or transform?
Which boundary type is indicated by a mid-ocean ridge: divergent, convergent, or transform?
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Divergent boundary. Plates separate and new crust forms between them.
Divergent boundary. Plates separate and new crust forms between them.
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Which seafloor feature is most directly associated with subduction of oceanic crust?
Which seafloor feature is most directly associated with subduction of oceanic crust?
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Deep-ocean trench. Where oceanic plates bend down and sink into the mantle.
Deep-ocean trench. Where oceanic plates bend down and sink into the mantle.
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What is a rift valley, and where is it commonly found relative to a mid-ocean ridge?
What is a rift valley, and where is it commonly found relative to a mid-ocean ridge?
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A valley at the ridge crest where crust is pulling apart. Forms where plates separate at spreading centers.
A valley at the ridge crest where crust is pulling apart. Forms where plates separate at spreading centers.
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Which seafloor measurement pattern indicates plates move away from a mid-ocean ridge?
Which seafloor measurement pattern indicates plates move away from a mid-ocean ridge?
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Heat flow is highest at the ridge and decreases outward. Hot magma at ridges cools as plates move away.
Heat flow is highest at the ridge and decreases outward. Hot magma at ridges cools as plates move away.
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Identify the relationship between seafloor age and distance from a mid-ocean ridge.
Identify the relationship between seafloor age and distance from a mid-ocean ridge.
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Seafloor age increases with distance from the ridge. Proves new crust forms at ridges and moves outward.
Seafloor age increases with distance from the ridge. Proves new crust forms at ridges and moves outward.
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Which seafloor location has the oldest oceanic crust: near a ridge or far from the ridge?
Which seafloor location has the oldest oceanic crust: near a ridge or far from the ridge?
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Far from the mid-ocean ridge. Older crust has moved away from its formation point over time.
Far from the mid-ocean ridge. Older crust has moved away from its formation point over time.
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What seafloor feature marks a divergent boundary where new oceanic crust forms?
What seafloor feature marks a divergent boundary where new oceanic crust forms?
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Mid-ocean ridge. Underwater mountain chain where plates separate and magma rises.
Mid-ocean ridge. Underwater mountain chain where plates separate and magma rises.
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What pattern of magnetic polarity on the seafloor supports seafloor spreading?
What pattern of magnetic polarity on the seafloor supports seafloor spreading?
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Symmetrical magnetic stripes on both sides of ridges. Mirror-image patterns prove new crust forms at the ridge center.
Symmetrical magnetic stripes on both sides of ridges. Mirror-image patterns prove new crust forms at the ridge center.
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Which continental fit is the classic example used as evidence for plate motion?
Which continental fit is the classic example used as evidence for plate motion?
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South America and Africa. Their coastlines match remarkably well when brought together.
South America and Africa. Their coastlines match remarkably well when brought together.
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Which seafloor location has the youngest oceanic crust: near a ridge or near a trench?
Which seafloor location has the youngest oceanic crust: near a ridge or near a trench?
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Near a mid-ocean ridge. New crust forms continuously at spreading centers.
Near a mid-ocean ridge. New crust forms continuously at spreading centers.
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Which observation about continental coastlines supports past connection of continents?
Which observation about continental coastlines supports past connection of continents?
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Matching shapes of continental margins (jigsaw fit). Coastlines fit together like puzzle pieces when reassembled.
Matching shapes of continental margins (jigsaw fit). Coastlines fit together like puzzle pieces when reassembled.
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What is Pangaea in the context of plate motion evidence?
What is Pangaea in the context of plate motion evidence?
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A former supercontinent containing most landmasses. All continents were joined ~250 million years ago.
A former supercontinent containing most landmasses. All continents were joined ~250 million years ago.
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What is a transform fault on the seafloor, in terms of plate motion?
What is a transform fault on the seafloor, in terms of plate motion?
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A boundary where plates slide past each other. Plates move horizontally past each other without creating/destroying crust.
A boundary where plates slide past each other. Plates move horizontally past each other without creating/destroying crust.
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Which seafloor feature offsets segments of mid-ocean ridges and indicates sideways motion?
Which seafloor feature offsets segments of mid-ocean ridges and indicates sideways motion?
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Transform fault. Fracture zones where plates slide past each other horizontally.
Transform fault. Fracture zones where plates slide past each other horizontally.
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What is the term for a linear chain of volcanoes formed as a plate moves over a hot spot?
What is the term for a linear chain of volcanoes formed as a plate moves over a hot spot?
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Hot spot track (volcanic island chain). Plate motion over stationary magma source creates age progression.
Hot spot track (volcanic island chain). Plate motion over stationary magma source creates age progression.
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Which part of a hot spot volcanic chain is usually the oldest if the hot spot is stationary?
Which part of a hot spot volcanic chain is usually the oldest if the hot spot is stationary?
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The volcano farthest from the active hot spot. Plate has moved farthest from the magma source over time.
The volcano farthest from the active hot spot. Plate has moved farthest from the magma source over time.
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Which option best indicates a divergent boundary on the seafloor: ridge or trench?
Which option best indicates a divergent boundary on the seafloor: ridge or trench?
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Ridge. Ridges mark where plates separate and new crust forms.
Ridge. Ridges mark where plates separate and new crust forms.
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