Geo Unit 1 Vocab

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Geo Unit 1 Vocab
2013-10-05 22:21:16
Geo 12

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  1. aftershocks
    series of less powerful earthquakes that follow the main quake. aftershocks may continue for days.
  2. andes mts.
    south american mountain range with many volcanoes made of andesite lava
  3. andesite lava
    lava found on continental volcanoes. it forms very steep-sided volcanoes
  4. anticline
    rock layers folded by compression. the upfold is known as an anticline and the downfold a syncline.
  5. asthenosphere
    the upper part of the mantle. this is a partly molten plastic zone in which convection currents are present. plates float on this zone.
  6. basalt
    a dark colored extrusive igneous rock (lava) usually found in ocean crust. forms sea floors.
  7. batholith
    a mass of intrusive igneous rock. sometimes covers thousands of square kilometers. if erosion removes overlying layers the batholith will be exposed.
  8. benioff zone
    earthquake zone at subduction zone.
  9. brittle fracture
    a break in rock caused by too much stress
  10. caldera
    a large volcanic crater created by a violent volocanic explosion or implosion.
  11. centrosphere
    the center (core) of the earth. consists of iner and outer layers.
  12. coal
    a fossil fuel produced from the compacted and pressurized remains of tropical vegetation.
  13. columnar jointing
    columns formed when basaltic lava cools and fractures.
  14. composite cone
    type of volcanic mountain. composed of layers of cinders and andesitic lava. pacific ring of fire volcanoes are composite cones.
  15. compression
    pressure forcing rock surfaces to be pushed together
  16. continental shelf
    the flat shallow ocean floor next to the continent. may stretch out for 100 kilometers or so before deep ocean is reached.
  17. continental slope
    the drop-off from shallow continental shelf to the deep ocean floor.
  18. crater lake, oregon
    example of a caldera filled with water
  19. dike
    a rock formation that results when magma breaks across rock layers
  20. ductile deformation
    as rock is subjected to stress for extended time, the rock may become permanently deformed.
  21. earthquake
    violent shaking of the earth's surface caused by a sudden displacement of subsurface rock masses.
  22. elastic deformation
    rock returns to its original shape after stress is removed
  23. epicenter
    point on the earth's surface directly above the focus.
  24. epeirogenesis
    continent building. continental surfaces have been elevated or depression, with little or no folding.
  25. fault
    a fracture in the earth's crust.
  26. fissure
    a long crack in the earth's crust. lava may occasionally extrude from fissures.
  27. fold mountains
    created when earth's crust is compressed and folded. himalayas, alps, rockies, appalachians are examples of fold mountains.
  28. focus
    point in the earth's surface where rock fractures, resulting in an earthquake.
  29. gabbro
    oceanic volcanic (igneous) rock with large crystals.
  30. geysers
    similar to hot spring but a blockage occurs in the fault line. water and steam collect, pressure builds, water and steam are forcefully expelled.
  31. graben
    a downshifted block of strata (rock layers) in between two faults. also known as a rift valley.
  32. horst
    uplifted block of strata in between two faults. also known as a block mountain.
  33. hot spring
    water heated by magma close to the surface that finds an escape route through cracks in the earth's crust.
  34. igneous
    rocks formed by the cooling and hardening of magma from within the earth's mantle.
  35. laccolith
    a dome-like pooling of magma that occurs underground between rock layers.
  36. lahar
    mudflow caused when a volcano's heat rapidly melts ice and snow on slopes of volcano.
  37. liquefaction
    literally means 'becoming a liquid'. when some types of soils (sand and silt) are shaken violently in an earthquake, the soil may liquefy and behave much like quicksand. soil strength is lost and buildings can topple or begin to sink.
  38. lithosphere
    the solid outer crust of the earth.
  39. locked fault
    when movement at a fault is prevented by excessive friction.
  40. magnitude
    the size of an earthquake
  41. mangroves
    submerged shorelines that support a distinct forest ecosystem adapted to living in seawater.
  42. metamorphic rock
    an igneous or sedimentary rock that has undergone a change by heat or pressure inside the earth's surface.
  43. mesosphere
    the layer of the earth directly below the crust. it extends to the outer core. also called the mantle.
  44. mid-ocean ridge
    location on the ocean floor where plates are diverging. here new land is being created.
  45. mohorovicic discontinuity (moho)
    boundary between the lithosphere and the mesosphere.
  46. nuees ardentes
    super heated, denser that air deadly volcanic gases.
  47. oil
    a fossil fuel produced from the compaction of minute sea creatures on the sea floor.
  48. ore
    a mined mineral.
  49. orogenesis
    process of mountain building
  50. pangea
    alfred wegner's super continent from which today's continents split and drifted to their present locations.
  51. plate tectonics
    the theory of plate tectonics state that the lithosphere is broken into a series of rigid plates which are propelled along by convection currents in the asthenosphere.
  52. p-waves
    primary or compression wave generated by an earthquake. it travels through the ground by compressing and expanding it.
  53. pyroclastics
    refers to any material blasted out of a volcano.
  54. richter scale
    measures the severity of earthquakes. each number is 10 times larger than the previous.
  55. sandstone
    example of sedimentary rock.
  56. scarp
    steep cliff that is result of vertical displacement of rock along a fault line.
  57. sediment
    small, erdoed particles of rock fragments carried by water, ice, and wind and deposited in low lying areas.
  58. sedimentary rock
    one of three main rock types. created when sediment collects in low-lying areas, is slowly pressurized and compacted into layered rock.
  59. seismograph
    instrument used to detect earthquakes.
  60. seismologist
    a scientist who studies earthquakes.
  61. shale
    an example of sedimentary rock
  62. shield cone
    ocean volcanoes with very gentle slopes. composed of basaltic lava.
  63. sial
    name given to the continental crust.
  64. sill
    a rock formation that occurs when magma intrudes between rock layers, cools, hardens, and may eventually be exposed by erosion.
  65. sima
    name given to the continental crust.
  66. strike-slip fault
    where plates move only horizontally past one another. also known as transform or tear fault. creates earthquakes.
  67. subduction zone
    a plate boundary where one plate over rides another plate forcing the other to dive down and be reclaimed by the mantle.
  68. subsidence
    a gradual settling of ground. may be caused by over use of ground water or weight of glacial ice.
  69. surface waves
    created when primary and secondary waves generated by an earthquake reach the surface, the result is a surface wave. surface waves travel like ripples on water.
  70. s-waves
    secondary wave or shear wave generated by an earthquake. it travels through the earth in a side to side motion.
  71. syncline
    rock layers folded by compression. the downfold is known as a syncline
  72. tear fault
    crack in the earth where only horizontal movement of rock occurs. also known as transform fault, strike-slip fault.
  73. tension
    process in which rock surfaces are pulled apart.
  74. transform fault
    a boundary where plates slide horizontally past each other with no vertical movement.
  75. trench
    deep area of the ocean where two colliding plates pull each other down.
  76. tsunami
    huge wave usually caused by an earthquake on the ocean floor or underwater volcanic eruption.
  77. volcanic neck
    the rock that is left standing when erosion exposes the hard volcanic rock inside an ancient volcano.