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  1. What evidence supports continental drift?
    • -The continents fit together
    • -Fossils of the late paleozoic area are found widely spread across continents
    • -Evidence of the location of global climatic belts
    • -evidence from mountain ranges and rock types
    • -paleomagnetism: magnetic minerals in basalt that line up with the Earth's magnetic field are frozen in place as the lava cools, recording the location of the planet's magnetic north pole at the time it formed
  2. Diagram the features that provide evidence for plate tectonics
    • -Bathymetry:seafloor has enourmous mountain ranges named mid-ocean ridges, deep trenches, huge fractures and some flat planes. 
    • -Paleomagnetism on the ocean floor- zebra stripes of different paleomagnetic polarity, sometimes the magnetic poles switch
    • -ages of rocks of the ocean floor:ocean rocks go rock youngest at mid-ocean ridges to oldest farthest from the ridges
    • -seafloor spreading: the mechanism for moving continents, the creation of new seafloor and the spreading of old seafloor away from the ridge axis
    • -Convection currents: mantle convection drives seafloor spreading
    • -Plate tectonics = continental drift + seafloor spreading
  3. Summarize the thermal processes driving plate movement
    • -mantle convection-convection cells form in the Earth's mantle
    • - the source of the heat is the Earth's core which warms the lower layer of the mantle which rises to the top of the mantle then spreads outward in both directions beneath the crust
    • -the material cools eventually becoming negatively buoyant and sinking, traveling back to the lower layer of the mantle to be warmed again
    • -upwelling mantle material rises beneath the mid-ocean ridges>the ridges have high heat flow>making them bouyant and they stand higher than the surrounding ocean floor
    • -heat causes the upper mantle to melt >produces basalt lavas that erupt at the mid-ocean ridge>creates new ocean crust
    • -the mantle mather spreads outward in both directions from the mid-ocean ridge carrying the oceanic crust with it, mantle cools as it moves further from its heat source
  4. Explain how density and buoyancy are related to plate tectonics
    • -if temperature of fluid rises, molecules move more vigorously and take up more space, since mass hasn't changed, density decreases
    • -lower density means warmed fluid has greater buoyancy than the fluid around it and rises 
    • -if the buoyancey for an object is equal to the force of gravity the object has neutral buoyancy
    • -lithosphere:crust and uppermost mantle
    • -asthenosphere- mantle and just below the lithosphere
    • -oceanic crust: thinner and denser
    • -continental crust-less dense but much thicker and more bouyant
    • isostasy: the earth's lithosphere floats on the denser asthenosphere
    • -bother oceanic and continental lithosphere are less dense than the mantle beneath them and are more bouyant so they float on the mantle
    • -when two slabs of lithosphere come together, what happens depends on their relative densities - the denser slab will sink beneath the less dense slab or if two continental lithospheres meet they are so buoyant neither will sink
  5. Describe plate boundaries
    • Convergent: plates move toward each other
    • 2 oceanic plates converge to create a subduction zone
    • when two oceanic plates collide, the denser of the plates plunges beneath the other in subduction
    • a continental and oceanic plate converge to create a subduction zone- the ocean plate subducts beneath the continental plate
    • partial melting of the subducting plate may form a chain of volcanoes
    • weo continental plates converge to create a mountain range

    • divergent boundary: plates move apart
    • spreading ridges where seafloor spreading occurs
    • new ocean crust forms as the plates move away from each other

    Transform Boundary: plates slide past eachother

    • plates move along faults-cracks in the crust
    • earthquakes- plates move in large jults
  6. Relate the causes of volcanoes, earthquakes, and earth resources to tectonic processes
    • Earthquakes
    • most are caused by the lithospheric plates moving against eachother
    • when the stresses build up enough energy they overcome the frictional forces and the two pieces slip past eachother and the energy that is released creates an earthquake
    • almost all earthquakes occur at all three types of plate boundaries
    • plate boundaries have their own earthquake depths

    • volcanoes
    • found at convergent and divergent boundaries where the mantle melts

    • earth resources
    • matallic minerals are found in subduction zones, they form n and near magma chambers
    • some magma bodies cool below the surface and form plutons which heat and supply fluids to the surrounding rock
  7. Summarize earthquake processes in terms of epicenter, focal mechanism, distance and materials, distance and the role these have to the magnitude
    • Epicenter: position where damage is greatest, point on Earth's surface directly above the focus-point in the crust where energy is released, seismographs can determine this
    • Focal Mechanism: the amount of motion that rocks along the fault undergo and the orientation of the fault
    • Dip-Slip Faults: has vertical motion
    • Normal Faults: the hanging wall goes down relative to the footwall
    • Reverse Fault: the hanging wall goes up relative to the footwall
    • Thrust Fault: reverse fault in which the fault plane is at an angle less then 45 degrees
    • Strike-Slip: only horizontal motion
    • Left-Lateral (sinistral) strike slip: left foot moves toward you
    • P waves: fastest, compressional waves, can travel through any substance, causes structures to compress and expand which weaken and collapse a building
    • S waves: travel in a side-to-side motion, only travel through solids
    • Surface waves: travel at the interface between two different substances, much slower than body waves, roll along the surface, like ripples, side to side and up and down, do significant damage because they are at the surface
    • -rayleigh and love waves

    • Damage:
    • strength and amplitude of the seismic waves
    • duration of shaking
    • geology of the area
  8. Diagram and explain the rock cycle
    • igneous rocks from when lava or magma cools and hardens 
    • sedimentary rocks form from sediment
    • -clastic: formed when broken peices of other rocks are compacted and cemented 
    • -organic: from from the remains of plants and animals
    • metamorphic: any rocks changed by heat and pressure
    • -foilated: have grains arranged into bands or layers
    • -nonfoliated: do not show banding
  9. Describe relative and absolute dating techniques, including how half-lives are used
    • Relative age:
    • age when compared with the afes of toher rocks, layers of sedimentary rock, law of super postion
    • igneous intrusions: hardened magma that was pushed up from the mantle, faults 
    • inclusions: pieces of rock that are made part of a newly forming rock
    • -
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2016-01-06 05:36:38

studying for cset science
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