plate tectonics

• Geology


  The science that studies the earth
• Lithosphere


  Composed of the crust and the upper mantle, constant but very slow in motion
• Plates


  Rigid sections of the lithosphere that move as a unit
• Plate Tectonics Theory


  The entire lithosphere of the earth is broken into numerous segments called plates
• Crust


  • Average density is 2.8g/cm3 and 5-50km thick
  • Continental crust is thicker but less dense
  • Oceanic crust is thinner but more dense
• Earthquake


  Vibration of earth due to the rapid release of energy
• Triangulation Method


  Measures earthquakes with 3 Seismographs
• Seismograph


  Device used to record earthquake waves
• Seismogram


  Record made by a seismograph
• Types of Plate Boundaries

  • Divergent Boundary - Constructive, creates rift valleys and mid-oceanic ridges
  • Convergent Boundary - Destructive, creates mountains, volcanos, or subduction zones that form large trenches
  • Transform Boundary - Conservative, creates deep trenches, and scarps and ridges
• Types of Convergent Plate Boundaries

  • Continental-Oceanic - The latter subducts under the former and volcanic arc forms above it. The pieces that subduct melts and becomes magma that rises.
  • Oceanic-Oceanic - The older plate will subduct under the other. Trenches and volcanic island arcs form above the younger plate.
  • Continental-Continental - They will buckle up and form mountain ranges.
• Subduction


  Bending of the crust towards the mantle
• Trench


  Submarine valleys, lowest part of the ocean
• Tsunami


  The Japanese term for "harbor wave," a series of ocean waves with very long wavelengths
• Continental Volcanic Arc


  Mountains formed in part by igneous activity associated with subduction of oceanic lithosphere beneath a continent
• Volcanic Island Arc


  A chain of volcanoes that develop parallel to a trench
• Hotspot

  Concentration of heat in the mantle capable of creating magma
• Magma


  Mass of molten rock
• Mid-Ocean Ridge


  A continuous mass of land with long width and height on the ocean floor
• Fracture


  A break in a rock with no movement
• Fault


  A break in a rock along which a movement has occurred
• Types of Faults


  • Normal Fault - ●⬇
  • Reverse Fault - ●⬆
  • Strike-Slip Fault - ⇄
• ]

  A) trench

  B) mid-ocean ridge

  C) asthenosphere

  D) strike-slip fault

  E) volcanic arc

  F) oceanic

  G) continental

  
• ]

  A) oceanic-oceanic

  B) continental oceanic

  C) continental continental

  
• \\

  A) divergent

  B) transform

  C) convergent