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45 Cards in this Set
- Front
- Back
What is the thin and solid outermost layer of the earth above the mantle?
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crust
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What is the layer of rock between the Earths's crust and core, contains most of Earths' mass?
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mantle
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What is the central part of the Earth?
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core
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What is a substance composed of 2 or more elements (chemically combined)
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compound
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Why do less dense compoud make up the Earth's crust while the densest compounds make up the core?
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because of the pull of gravity
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What are the five main physical layers of the Earth?
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-lithosphere
-asthenoshpere -mesosphere -outer core -inner core |
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What is the outermost, rigid layer of the Earth?
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lithosphere
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What is the 2nd layer that's solid rock that can flow, plates move on it, and is malleable?
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asthenosphere
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What is the strong, lowest part of the mantle?
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mesosphere
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What is the liquid layer of the core?
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outer core
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What is the solid, dense center? (solid because of preasure)
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inner core
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What is the block of lithosphere that consists of the crust and rigid most outer layer of the mantle and moves around top of asthenosphere?
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tectonic plate
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What types of tectonic plates are there?
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continental, oceanic, and a combo of both
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What are some ways scientists know about the structure fo the Earths' interior?
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-measure the speed of seismic waves
-travel times of seismographs |
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Who was Alfred Wegner?
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scientist who proposed the hypothesis of the continental drift
(early 1900s) |
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What is the Continental Drift Hypothesis?
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hypothesis that states continents once formed a single landmass, broke up, and driftedd to their present location
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What evidence supports the Continental Drift Hypothesis?
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-fossils of same organisms found of both sides of ocean
-similar rocks found on differnt continents -coastlines roughly matche up -mt. ranges would line up if land was back together |
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What was a single landmass when continents were joined?
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Pangaea
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-magma rises to surface and solidifies, fills gap between moving tectonic plates
-new crust forms |
Sea Floor Spreading
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What evidence supports the sea floor spreading hypothesis?
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oldest crust farthest away from ridge
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List 2 things that the reversed magnetism of the ocean floor tells us about the earth's history.
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-all ocean floor was not formed at once
-earth's magnetic poles have reversed in the past |
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What is an underwater mountain chain that runs through Earth's ocean basins?
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mid-ocean ridge
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What occurs in the rift valley at the mid ocean ridge?
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magma rises, lava hardens into new ocean floor
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What is the theory that explains how large pieces of the Earth's outermost layer move and change shape on the asthenosphere?
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plate tectonics
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What are the 3 types of boundaries?
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-convergent
-divergent -transform |
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What boundary is it when plates collide?
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convergent
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What boundary is it when plates seperate?
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divergent
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What boundary is it when plates slide past each other?
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transform
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What is believed to cause the motion of the tectonic plates?
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-ridge push
-slab pull -convection |
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What is it when higher ridge pushes lower oceanic lithosphere down?
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ridge push
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What is it when sinking plate edge is pulled by gravity and pulls on the rest of the plate?
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slab pull
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Explain how scientists use GPS to measure the rate of tectonic plate movement.
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radio signals are continuously beamed from satellites to GPS ground stations
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What is it when oceanic crust collides with continental crust, and the denser oceanic crust sinks into the asthenosphere?
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subduction
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What is it when the shape of rock changes cuz of stress?
(rock layers can bend and brake) |
deformation
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What is stress that occurs when an object is squeezed?
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compression
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What is stress that occurs when forces stretch an object?
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tension
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What happens when folding occurs with rock layers?
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rock layers bend cuz of stress
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What is the surface along wich rocks break and slide past each other?
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fault
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What are the 3 types of faults?
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-normal
-reverse -strike slip |
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What fault occurs when plates are pulled apart?
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normal
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What fault occurs cuz of compression?
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reverse
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What fault occurs when opposing forces break rock and move horizontally?
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strike slip
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What forms from collisions at convergent boundaries, can form highest mts. in world, and is the most common?
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folded mountains
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What forms when tension at normal fault cause large blocks of crust to drop down relative to others? (sharp, jagged rocks)
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fault block mountains
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What usually forms at a convergent boundary where suduction occurs?
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volcanic mountains
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