4TH UNIT SCIENCE REVIEWER

• Aftershock


  Minor shaking of the earth
• Atmosphere


  Gaseous envelope surrounding and protecting earth
• Continent


  Earth's divisors of land
• Liquefaction


  A process by which loose saturated sand lose strength
• Magma


  Molten rock material
• Pyroclastic Materials


  Volcanic rock, ash, lava, and gas
• Ridge


  Long narrow elevation
• Rift Valley


  Depression in the ground caused by earth's crust spreading apart
• Sea level


  The level of the sea
• Diameter: 12,742 kilometers
• Mass: 5.97 x 10^24 kilograms
• Distance (Sun): 149.6 million kilometers
• Length of Day: 24 hours
• Length of Year: 365.24 days
• Composition: 32.1% iron, 30.1% oxygen, 15.1% silicon, 13.9% magnesium, and 2.9% sulfur
• The Earth's axis is tilted at an angle of about 23.5 degrees
• The tilt is responsible for the Earth's seasons and variation in daylight
• Earth's orbital plane is the flat path
• The equator is an imaginary line that circles the Earth
• Pangaea


  A supercontinent proposed by German Meteorologist Alfred Wegener
• Panthalassa


  The big ocean surrounding Pangaea
• Continental Drift Theory


  Used to support the idea of Pangaea and Panthalassa
• Tectonic Plates


  Splits the earth's crust into continents resting on slabs of rock, floating on the upper mantle
• Plate Tectonics


  The process wherein the plates are moving and interacting
• Fault


  Cracks in earth's surface
• Plate Boundaries


  The set of points at which the plates meet, each with a type of force called stress
• Types of Plate Boundaries

  • Divergent Plate boundaries
  • Transform Plate boundaries
  • Convergent Plate Boundaries
• Divergent Plate boundaries


  Where two plates move away from each other, creating stress called tension, separating land masses and forming seas, oceans, volcanoes, and ridges or rift valley
• Transform Plate boundaries


  Where two plates move past each other horizontally, creating stress called shearing, causing earthquakes when rocks break
• Convergent Plate Boundaries


  Where two plates collide, creating stress called compression, producing earthquakes, volcanic activity and forming mountain ranges
• Geologists


  Scientists who study the solid, gaseous, and liquid matter that constitute Earth as well as the process
• Layers of Earth

  • Crust
  • Mantle
  • Outer core
  • Inner core
• CrustEarth's thin, hard outer shell

  • Where most earthquakes occur
  • Classified into continental and oceanic crust
• Mantle


  • Largest layer of Earth, making up 67% of its total mass
  • Divided into upper and lower mantle
• Upper Mantle


  • Starting at the base of the crust, around 7 to 410 km down
• Lower Mantle


  • 660 to 2891 km thick
  • Overall the mantle is 2900km thick
• Mohorivicic Discontinuity (Moho)


  Boundary between Earth's crust and the upper mantle
• Core


  • Divided into outer and inner core
• Outer Core


  • A ball of very hot metals, made up of iron, nickel, sulfur and oxygen
• Gutenberg Discontinuity


  Boundary between the outer core and lower mantle