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lower mantle
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molten rock
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When was Pangaea formed?
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Permian Period
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crust
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the thinnest of earth's layers
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Seismograph
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a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake). , a device that writes down (records) the movements of the earth
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divergent
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magma rises, new crust, volcanoes, underwater mountain ranges along PB, new sea floor, and shallow eqs along pb
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Alfred Wegner
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hypothesized that the continents slowly drifted apart from a single land mass
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Mars
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huge dust storms that cover the atmosphere (wind on planet)
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convergent boundary
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the boundary between two colliding tectonic plates
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Mantle
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Layer of the Earth directly underneath the crust.
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epicenter
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point on earth surface directly above where an earthquake occurs
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Earthquake
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The shaking that results from the movement of rock beneath Earths surface.
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mid-ocean ridge
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any of several seismically active submarine mountain ranges that extend through the Atlantic, Indian, and South Pacific oceans: each is hypothesized to be the locus of seafloor spreading.
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subduction
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the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle, convection currents under the lithosphere push new crust that forms at the mid-ocean ridge away from the ridge and toward a deep-ocean trench
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mesosphere
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The strong lower part of the Mantle between the Asthenosphere and the outer core
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scientific theory
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a well-tested concept that explains a wide range of observations
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Features of Transform
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Faults over a long geographical area.
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Basalt
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A dark, dense, igneous rock with a fine texture, found in oceanic crust.
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Subduction Boundary
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A convergent boundary where an oceanic plate is plunging beneath another, overriding plate.
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stress
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A force that acts on rock to change its shape or volume.
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asthenosphere
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the soft layer of the mantle on which the lithosphere floats
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tectonic plate
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a piece of the lithosphere that moves around on top of the asthenosphere
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Fault
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A break in Earths crust where slabs of rock slip past each other.
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What is a mid-ocean ridge?
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an underwater mountain range right down the middle of the ocean
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continental drift
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the evidence of this was: the fit of the continents, fossil evidence, matching rock sequences, and climate evidence
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Where does a transform boundary occur?
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A transform boundary usally has eathquakes on it.
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The asthenosphere is ______
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a layer of hot magma that the plates float on.
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How is it that the Pacific Ocean is shrinking?
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The Pacific Ocean is shrinking because deep ocean trenches swallow more oceanic crust than the mid-ocean rdge can produce.
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Waves
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...
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P Wave
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...
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Synapsida
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1 post-orbital opening
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lithosphere
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crust and upper mantle
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L-wave
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surface wave; causes most damage
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3700 miles
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Earth's depth is about
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Normal fault
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The plate moves down
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the southern part of pangaea
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gondwana
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hotspot
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a small, long-lasting, extremely hot region in the mantl (lithosheric movement on hot spot creates the hawaiian islands)
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Seismic activity, volcanism, and mountain building all occur at
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plate boundaries
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pangea
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a hypothetical continent including all land mass of the earth prior to the triassic when it splits into laurasia and gondwanaland
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Oceanic crust
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the thinnest type of crust
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Granite
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A usually light-colored igneous rock that is found in continental crust
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when plates move past each occurs.
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sliding
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focus
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the location within Earth along a fault at which the first motion of an earthquake occurs
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ocean-ocean
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two oceanic plates collide, one is eventually forced down and a subduction zone forms
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Seismometer
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a device that measures the actual movements of the ground
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trench
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narrow drops/cliffs on the sea floor with steep sides. form the deepest parts of the oceans
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What does the upwelling of matireal create?
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magma
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Felsic
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Describes magma or igneous rock that is rich in feldspars and silica and that is generally light in color.
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Craton
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Oldest rocks (3.9 byo) Ex: Venezuela, angel falls
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...
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Which prices of evidence did Wegener use to support his theory of continental drift?
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Lava
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Molten rock that comes to Earth's surface through a volcano or other crack in Earth's crust.
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convection current
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A circulation pattern in which material is heated and
rises in one area, then cools and sinks in another area, flowing in a continuous loop.
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sea-floor spreading
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Hess's theory that new seafloor is formed when magma is forced upward toward the surrface at a mid-ocean ridge.
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Plate Boundary
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the region where two tectonic plates are in contact
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plate-mantle model
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mantle plumes extend from mantle core boundary and cause convection within the mantle
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sediment
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particles that can no longer be held, or suspended in a liquid
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pangaea evidence
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fit of south america and africa (continental shelves)
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s-wave
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CAN ONLY GO THROUGH SOLIDS. up and down motion. THATS HOW WE KNOW LIQUID CORE
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fault line
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rock layers displaced (moved) along a crack; earthquakes often occur here
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moment magnitude
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a more precise measure of earthquake magnitude than the Richter scale, which is derived from the amount of displacement that occurs along a fault zone and estimates the energy released by an earthquake
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fractional crystallization
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The process by which the crystals formed in a cooling magma are segregated from the remaining liquid at progressively lower temperatures.
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Seismic Waves
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Scientists study these waves and how they travel through Earth.
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Outer Core
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The layer located around the inner core containing molten material made of mostly Iron and Nickel
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subduction zone
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the region where an oceanic plate sinks down into the asthenosphere at a convergent boundary, usually between continental and oceanic plates
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plate tectonics
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a theory stating that the earth's surface is broken into plates that move
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Rift Valley
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Forms at a continental - continental divergent boundary
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lithosphere is composed of the
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plates and sea floor
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The single landmass split into two big continents
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Lauraisa
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Island Arc
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A chain of volcanic islands formed at an ocean-ocean convergent boundary
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What is the driving mechanism for plate tectonics?
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Convection in Mantle
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astenosphere
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the soft layer of the mantle on which the lithospere floats
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divergent ocean/ocean boundary
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A divergence of two oceanic plates. Forms a mid ocean ridge
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divergent boundary
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a place where two tectonic plates are moving apart
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Love Waves
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Surface waves that shear the ground in a horizontal direction. Can only travel through solids. Third to arrive.
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Volcanic Ash
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fine grained particles blown out of a volcano from an explosive eruption
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transform boundary
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a boundary where two plates slide past eachother
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Deep Ocean Trench
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An underwater canyon where rock sinks back into the crust.
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metal
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Earth's inner core is a dense ball of solid...
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continental - continental collision
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occurs where two plates carrying continental crust push together
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the man that came up with contenintal drift
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alfred wegener
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What landform do you find at a divergent boundary?
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mid ocean ridges
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normal polarity
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a magnetic field that is the same as that which exists at present
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When oceanic crust meets continental crust
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oceanic crust subducts under continental crust.
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Divergent plate boundaries.
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Why the ocean is getting wider and wider.
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stress and list 3 types
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forces per unit area acting on mineral:
1) compression
2) tension
3) shear
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Richter scale
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a logarithmic scale of 1 to 10 used to express the energy released by an earthquake
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rocks found closest to the mid ocean ridge
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are the youngest seafloor rocks
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how the magnetic field influences your life
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alows compasses to work and protects from solar winds
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earths moveing crust or a peice of crust
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what is it meant by a plate?
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Gondwana
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Southern Pangaea
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One big continent
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Pangaea
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Seuss
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(1864) Austrian geologist, Gondwanaland was first proposed.
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continental continenetal convergence
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results in mountains
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Continental crust
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Thicker, less dense crust
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top layer of the earth
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crust
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slab pull
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Tectonic process associated with convection currents in earth's mantle that occurs as the weight of the subducting plate pulls the trailing lithospere into a subduction zone.
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radiation
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the transfer of enegy through space
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plutons
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intrusive rock bodies formed when magma cools
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Mohoravic Discontinuity (MOHO)
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Located under the continents.
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earthquake magnitude
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measurement of an earthquakes strength
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Where does seafloor spreading occur?
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mid-ocean ridge
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Evidence of Plate Tectonics
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1. Seafloor spreading
2. Paleomagnetism - ocean floor lies in magnetized "stripes" recording direction of magnetic field at the time it formed
3. Drilling samples - rocks closer to ridge younger than rocks farther away
4. Earthquake patterns - deep earthquakes at subduction zones
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Absolute time
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Geologic time measured in years, deterimined by geologic
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Panthalassa Ocean
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The large world-spanning ocean when Pangaea existed
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rifting
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the process by which earth's crust breaks apart
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Harry Hess
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In 1960, an American geologist, proposed that the ocean floors move like conveyor belts, carrying the continents along with them. This movement begins at the mid-ocean ridge.
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transform boundries
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plates grind part eachother causing earthquakes
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deep sea trenches are more likely found at which boundaries?
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convergent
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pressure
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the result of a force distributed over an area
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Frequency
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the number of complete waves that pass a given point in a certain amount of time
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zone where one plate sinks below another
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subduction zone
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Rayleigh Waves
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Surface waves that travel in a backward-rotating, elliptical motion, causing both vertical and horizontal ground movement. Can travel through solid, liquid, and gas. Fourth to arrive. Dangerous.
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magnetic field
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The magnetic field that surrounds the Earth, believed to be formed by the spinning of the inner and outer core.
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Convergent boundary:
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2 plates move TOGETHER (lithosphere is destroyed)
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Convergent plate boundary
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Area where earth's lithospheric plates are pushed together. See subduction zone. Compare divergent plate boundary, transform fault.
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deep-sea trench
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A long, narrow, steep sided trough that runs parallel to continental margins or to volcanic island chains.
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Magma
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Molten rocks that is inside of a volcano
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Alfred Wegener
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A German scientist who proposed the theroy of continental drift
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crust density
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oceanic crust is more dense than continental crust
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core
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made up of the outer and inner core
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interferogram
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two radar images of the same region can form this
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Features of Divergent
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- mid-ocealn ridges
- rift valleys
- fissure volcanoes
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Exist in the Appalachian Mountains and in Greenlan
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Rock Structures
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density
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The amount of mass in a given space; mass per unit volume.
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sea floor spreading
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The process by which molten material adds new oceanic crust to the ocean floor.
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S - P interval
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In earthquake seismology, the time interval between the first arrivals of transverse (S) and longitudinal (P) waves, which is proportional to the distance from the earthquake source.
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What is subduction
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The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
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Ring of Fire
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A major belt of volcanoes that surrounds the outer rim of the pacific ocean.
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where does convergent happen
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indian plate colliding with eurasian plate
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Convection Currents
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In the earth's mantle are what drive plate motions. Convection currents are driven by the simple fact that hot things such as gases and liquids rise while cool things fall.
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heat transfer by the movement of liquids and gases
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what is convection?
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is the process of force placed on a given material
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Formation
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If the rate of seafloor spreading is 10km on the left side of the North Atlantic Ocean Basin over 2 million years, what is the rate of seafloor spreading in cm/year? Show all work!
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10km = 1,000,000cm
1,000,000cm/2,000,000years = 1/2 = .5cm/year
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hot spot
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plume of super heated magma rise up at certain locations which burns a hole in the crustal plate
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Why is this happening?
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The Atlantic ocean has the mid-ocean ridge which has lava flow about every year and pushes out the rock around it. The Atlantic ocean expands about two inches every year pushing the continent with it.
Read more: http://wiki.answers.com/Q/Why_is_the_Atlantic_ocean_expanding#ixzz1C3F8cJ5d
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what drives the movement of plates
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the convection belts of the lithosphere
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The three types of plate boundaries are:
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1. Transform Boundaries
2. Divergent Boundaries
3. Convergent Boundaries
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evidence that outer core is liquid
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it is spinning 550 miles per hour
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they formed or were created at different times
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Why does Antarctica have coal and striations?
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What evidence is there that led to the plate tectonic theory?
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1960's- Harry Hess of Princeton University proposed that in the earth's mantle there are currents of low-density molten material heated by earths radioactivity and these cause convection cells within the mantle. It was proposed that the deep ocean trench
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