module 6

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module 6
2014-12-11 18:43:24
physcial science
science 6
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  1. earths crust
    earths outermost layer of rock
  2. sediment
    small solid fragments of rock and other materials that are carried and deposited by wind, water, or ice.  Examples would be sand, mud, or gravel.
  3. sedimentary rock
    rock formed when chemical reactions cement sediments together
  4. igneous rock
    rock that forms from molten rock
  5. metamorphic rock
    igneous or sedimentary rock that has been changed into a new kind of rock as a result of great pressure and temperature
  6. plastic rock
    rock that behaves like something between a liquid and a solid
  7. earthquake
    vibration of the earth that results either from volcanic activity or rock masses moving along fault
  8. fault
    the boundary between two sections of rock that can move relative to another
  9. focus
    the point where earthquakes begin
  10. epicenter
    the point on the surface of the earth directly above and earthquakes focus
  11. scientist often separate the earth into five distinct sections. name them
    crust, mantle, core, atmoshere, hydrosphere
  12. of the five sections listed in problem 2 which can we observe directly
    crust and atmosphere and hydroshpere
  13. what two regions of the earth does the moho discontinuity separate? what about the gutenberg discontinuity? what about the lehmann discontinuity?
    • a) the crust and the mantle 
    • b) the mantle and the core 
    • d) the outer and the inner core
  14. what is the difference between the ways that igneous rock and sedimentary rock form
    igneous is formed from molten rock and sedimentary rock is formed from solid fragments of rock and other materials
  15. Of the 3 types of rock discussed in this module which starts as a diff type of rock?
    metamorphic rock
  16. what is the main thing scientist observe in order to learn about the makeup of the earths interior
    seismic waves
  17. which is a solid the inner core or the outer core . why is one solid while the other liquid
    • the inner core is solid because of freezing pressure
  18. where is the magnetic field of the earth generated
    the core
  19. what causes the magnetic field of the earth
    the electrical current in the earths core
  20. give a brief description of the two main theories that attempt to explain the earth's magnetic field
    • The dynamo theory says that the motion of the core is due to temperature differences in the core and the rotation of the earth.  This motion caused the motion of electrical charges in the core, which creates electrical current. 
    • The rapid decay theory states that the electrical current in the core started as a consequence of how the earth formed and is decreasing over time.
  21. what makes the rapid decay theory more valid than dynamo
    • The rapid decay theory has been used to accurately predict the magnetic fields of other planets.  The dynamo theory failed at this.
  22. why is a catastrohpe like the worldwide flood in noah time an essential part of the earths history  if the rapid decay theory is true
    catastrophes like that point to  the theory where  the magnetic field has reversed sometimes
  23. what 2 good reasons make scientist ignore the more scientific valid rapid  decay theory
    • 1 if they believed it they would have to believe the earth is younger than a billion years old
    • .2 most scientists don't believe in a cataclysmic event that happened
  24. why would life cease to exist if there were no magnetic field
    if there was no magnetic field the cosmic rays would kill us
  25. what are the plates in the plate tectonics
    islands of rock that float on the asthenosphere
  26. what can happen when plates collide
    • One plate can slide under another and for a trench.  
    • The plates can move away from each other, allowing magma to rise and create new crust.  The plates can push against each other causing the crust to fold.
    • The plates can slide along each other.
  27. what is pangae
    A hypothetical supercontinent that might have existed in the earth's past
  28. why do otherwise good scientist ignore the plate tectonic theory despite the evidence
    scientist who belive in the bible think that the earth would have to billions of years old for the theory to work so they don't consider it a valid theory
  29. what causes earthquakes
    when rock masses move along the fault or volcanic activity
  30. describe the elastic rebound theory of earthquakes
    masses of rock have fault between them as they try to move they bend eventually  they break free from each other and rebound to normal shape.  The resulting vibrations are what we feel as an earthquake
  31. a seismologist detects an earthquake that measures 4 on the richter scale . later he detects on the measure 8. how many more times energy does the second earthquake release as compared to the first
  32. name the 4 kinds of mountains. what is required for the formation of each
    • fault block mountain ; need vertical motion along a fault
    • folded mountian; need rock masses pushing against each other
    • domed mountian & volcanic mountain; need magma from the earth's mantle