Integrated Science 1 Q4

• Rheological Layers of the Earth:

  • Lithosphere
  • Asthenosphere
  • Mesosphere
  • Outer core
  • Inner core
• Lithosphere - outermost layer, includes crust and upper mantle. 0-100km
• Asthenosphere - below the lithosphere, flows easily like soft plastic, but it is NOT liquid. 100-350km
• Mesosphere - below the Asthenosphere. Like stiff plastic. 350-2900km
• Outer core - liquid iron and nickel. 2900-5100km
• Inner core - solid iron and nickel. 5100-6370km
• Chemical Layers of the Earth:

  • Crust
  • Mantle
  • Core
• Crust:

  • Oceanic crust - basalt rock (heavy and dark) 5km thick
  • Continental crust - granite rock (thick and light) 70km thick
• Mantle:

  • Upper mantle (Litho and Astheno) - stiff, dark, and dense. Composed of peridotite (iron and magnesium) In the Asthenosphere, the rocks are soft and plastic like.
  • Lower mantle (Meso) - hot and molten magma rock; stiff rocks.
• Core:

  • Outer Core - melted nickel and iron; liquid flow. The source of Earth's magnetic field.
  • Inner Core - innermost and the hottest layer of the Earth; solid nickel and iron. Solid due to high pressure.
• Tectonics - motion of the lithospheric plates (tectonic plates)
• Lithospheric movements - caused by convection currents (mode of heat transfer that causes fluids to move) which makes the plates move slowly and continuously
• Divergent Plate Boundaries- plates that move away from each other
• Convergent Plate Boundary - two or more tectonic plates move towards one another
• Transform Plate Boundary - when two plates slide past each other horizontally
• Alfred Lothar Wegener - proponent of the Continental Drift Theory
• Continental Drift Theory - The theory that all continents we know of today used to be part of a super continent called Pangaea.
• Five Evidences of CDT:

  • Continental Jigsaw Puzzle
  • Matching of fossils across seas
  • Rock Types
  • Glacial grooves
  • Coal deposits
• Seafloor Spreading Theory- proposed by Harry Hess and Robert Dietz
• Seafloor Spreading Theory Evidences

  • At mid-ocean ridges, rocks are younger
  • Rocks away from mid-ocean ridges are older
  • Sediment on ridge is thinner
  • Rocks on the ocean floor are younger than continental rocks
  • Geomagnetic anomalies such as magnetic field reversals and polar wandering support this theory
• Earthquakes - shakings of the Earth's grounds when rocks under move.

  • These are mostly caused by the release of pressure built up between moving lithospheric plates
• Fault - A fracture in the rocks that make up the Earth's crust
• Seismic waves - waves that transmit the energy released by an earthquake
• Epicenter - the point on the surface of the earth directly above the focus of an earthquake
• Focus - the point within the Earth where the earthquake originates
• Two types of waves travelling from an earthquake's focus

  • Body waves
  • Surface waves
• Body waves:

  • P waves - longitudinal; compressional
  • S waves - side-to-side; perprendicular
• Surface waves:

  • Rayleigh waves
  • Love waves
• Seismographs record ground motion in a seismogram
• Triangulation is the process of identifying the epicenter
• MAGNITUDE measures the energy released from an earthquake

  INTENISTY measures the energy felt by people
• Minerals are naturally occurring, inorganic solids with a highly ordered atomic arrangement and a definite chemical composition
• Rocks are naturally occurring, solid masses composed of one or more minerals

  • Monomineralic rocks - only one mineral
  • Conglomerate rocks - one or more minerals
• Color of a mineral - most recognizable feature of a mineral.

  • Monochromatic minerals - have only one color
  • Polychromatic minerals - multicolored minerals
• Diaphaneity - ability of a mineral to transmit light
• Luster - how light is reflected off a surface, can be metallic, non metallic or dull
• Streak - mineral's color in pulverized form. This is more reliable than unpulverized color
• Hardness - mineral's resistance to scratching.
• Cleavage - mineral's tendency to break along points of weakness
• Igneous rocks - magma that have cooled and solidified, this is the youngest form of rock