Earth science 2

• Geology


  The study of the Earth's structure, history, and processes involved in it
• Parts of the Earth

  • Geosphere
  • Hydrosphere
  • Atmosphere
  • Biosphere (where life exists)
• Crust


  Outermost layer of the Earth; up to 100 km below sea level
• Continental Crust (sial)


  • Portion of the crust not covered by the ocean
• Oceanic Crust (sima)


  • Portion of the crust under the ocean
• Lithosphere


  Region made of solid rocks; includes the crust and the upper solid part of the mantle
• Asthenosphere


  Region made of semi-solid rocks; portion where rocks begin to melt; divided into a soft upper layer and a hard lower layer
• Mantle


  Layer of the Earth under the crust to 2900 km into the center; made mostly of molten rocks
• Outer Core


  Made mostly of molten elements, mostly iron and nickel - 3150km
• Inner Core


  Made of solid light elements like iron and nickel. 6370 km
• Tectonic Plates


  Rigid pieces of the Earth's crust and upper mantle
• Plate Tectonics


  A scientific theory that describes the large-scale motions of the Earth's lithosphere
• Convection currents caused plates to move
• The lithosphere is 100km thick
• The Repetti Discontinuity is at 670km depth
• The Gutenberg Discontinuity is at 2900km depth
• The Lehmann Discontinuity is at 3150km depth
• Enumerate the interior of the earth.

  • Continental crust(sial)
  • Oceanic crust (sima)
  • Upper mantle
  • Partially molten asthenosphere
  • solid asthenosphere
  • Mantle transition
  • Lower mantle
  • Outer molten core
  • Inner solid core
• The 5 discontinuities of the earth

  • Conrad discontinuity
  • Moho (mohorovicic) discontinuity
  • Repetti discontinuity
  • Guttenberg discontinuity
  • Lehmen discontinuity
• Enumerate the km interior of the earth:

  • 5km
  • 100km
  • 200km
  • 400km
  • 670km
  • 2900km
  • 3150km
  • 6370km
• Crust is the thinnest under the ocean and thickiest under continents
• Crust is the least dense layer.
• Oceanic crust is more dense than the continental crust
• Continental Drift Theory


  Alfred Wegener theorizes that the Earth had a single continent through most of geologic time
• Evidence for Continental Drift Theory


  • Jigsaw-like fit of continental boundaries
  • Similarities between coastal rock formations between facing continental coasts
• Pangea


  The singular super continent
• Panthalassa


  The vast ocean surrounding Pangea
• Supercontinents

  • Furasia
  • Mu
  • Averca
  • LAURASIA
  • Разка
  • Occas
  • Famys
  • GONDWANA
• Sea-floor Spreading


  The process in which the ocean floor is extended when two plates move apart
• Plate Boundaries

  • Divergent Boundary
  • Convergent Boundary
  • Transform Boundary
• Divergent Boundary


  • Plates MOVE AWAY from each other
  • Constructive (new crust is created)
  • Can cause formation of ridges (ex. Mid-Atlantic Ridge)
• Convergent Boundary


  • Plates MOVE TOWARDS each other
  • Destructive (crust is destroyed as they submerge)
  • Oceanic-continental-forms trenches
  • Oceanic-oceanic-forms trenches
  • Continental-continental-forms mountains ranges, volcanoes
• Transform Boundary


  • Plates MOVE ALONG OR SLIDE PAST EACH OTHER
  • Conservative (crust is neither created nor destroyed)
• Earthquake


  Shaking of the ground caused by the release of tension built up in the plate boundaries
• Parts of an Earthquake

  • Fault scarp
  • Epicenter
  • Wave fronts
  • Focus
  • Fault
• Focus


  Point beneath the Earth's surface where rocks break under stress and the plates shift causing an earthquake
• Epicenter


  Center of the quake on the surface directly above the focus
• Body Waves


  Seismic/energy waves that travel underground from the focus to the surface
• Primary or P waves


  Compressional; fast and can travel through all mediums; particles move in the direction of the wave
• Secondary or S waves


  Shears; slower than P waves and can only travel through solid rock; particles move perpendicular to the direction of the wave