View
230
Download
0
Category
Preview:
Citation preview
Structure of the Earth
Compositional (Chemical) Compositional (Chemical) LayersLayers
Crust: Low densityCrust: Low density High in silicon (Si) and oxygen (O)High in silicon (Si) and oxygen (O)
Moho: Density boundary between crust and Moho: Density boundary between crust and mantle mantle
Mantle: Higher densityMantle: Higher density High in Magnesium (Mg) and Iron (Fe)High in Magnesium (Mg) and Iron (Fe)
Core: High in Nickel (Ni) and Iron (Fe)Core: High in Nickel (Ni) and Iron (Fe)
Earth: The Giant Magnet
Magnetic field created by liquid iron Magnetic field created by liquid iron convecting in outer core.convecting in outer core.
Magnetic field directs solar winds (ionized Magnetic field directs solar winds (ionized particles) around the Earth or to the poles.particles) around the Earth or to the poles.
Aurora Borealis
Heat Flow in the Earth
Heat sources: Heat sources: latent heat from the formation of the Earthlatent heat from the formation of the EarthRadioactive decay in the core and mantleRadioactive decay in the core and mantle
Temperature at core: 3000-5000Temperature at core: 3000-5000°° C C
Cooling processes:Cooling processes:Convection currentsConvection currentsPlate tectonics (volcanoes)Plate tectonics (volcanoes)
Mechanical (Physical) Layers of the Earth
Lithosphere: Crust and upper, solid part of the mantle; “plates” in plate tectonics
Asthenosphere: Partially molten part of mantle; location of convection current that drive plates
Outer core: Liquid
Inner core: SolidGreatest temperatures, solid due to intense pressure
Evidence for Structure of the Earth
Seismic (earthquake) wavesSeismic (earthquake) waves
P waves (Primary): Longitudinal P waves (Primary): Longitudinal (compressional) waves; faster, can move (compressional) waves; faster, can move through any matterthrough any matter
S waves (Secondary): Transverse waves. S waves (Secondary): Transverse waves. Can only travel through solid matter.Can only travel through solid matter.
Evidence for Structure of the Earth Cont.
S waves can not travel through the outer S waves can not travel through the outer core. core.
Rock Types
Igneous: Solidified molten magmaIgneous: Solidified molten magma
2 types of Igneous2 types of Igneous
Extrusive (volcanic) = erupted Extrusive (volcanic) = erupted lavalava
Cools more quickly, so only small crystals Cools more quickly, so only small crystals form. form.
Intrusive (plutonic) = never erupted Intrusive (plutonic) = never erupted magmamagma
Cools more slowly within the earth, so larger Cools more slowly within the earth, so larger crystals can form.crystals can form.
Quartz= Silica (SiOQuartz= Silica (SiO22), light ), light color. Magma high in silica is color. Magma high in silica is viscous.viscous.
High silica magma found in High silica magma found in more explosive volcanoes due more explosive volcanoes due to build up of pressure with to build up of pressure with more viscous magma. more viscous magma. Forms stratovolcano (cone Forms stratovolcano (cone shape)shape)
Low silica magma found in less Low silica magma found in less explosive volcanoes. explosive volcanoes. Form shield shape.Form shield shape.
Extrusive Igneous Rock
BasaltBasalt AndesiteAndesite RhyoliteRhyolite
Low in silicaLow in silica High in SilicaHigh in Silica
BlackBlack Pale pink, greyPale pink, grey
Intrusive Igneous Rock
GabbroGabbro DaciteDacite GraniteGranite
Low in SilicaLow in Silica High in SilicaHigh in Silica
BlackBlack Pale Grey, pinkPale Grey, pink
Sedimentary Rock
Sedimentary rock: formed by compaction of Sedimentary rock: formed by compaction of sediments. Classified by particle size.sediments. Classified by particle size.
Sandstone
Shale
Sedimentary Rock cont.Sedimentary Rock cont.
Almost all fossils found in Almost all fossils found in sedimentary rocksedimentary rock
Almost all fossil fuels (coal, oil, Almost all fossil fuels (coal, oil, gas) found in sedimentary gas) found in sedimentary rock.rock.
Metamorphic RockMetamorphic Rock
Metamorphic rock is Metamorphic rock is rocked that has been rocked that has been changed by heat and/or changed by heat and/or pressure. pressure.
Caused by burial and Caused by burial and proximity to volcanic proximity to volcanic areas.areas.
Dense, often streaks/folds Dense, often streaks/folds Many gemstones are Many gemstones are metamorphic.metamorphic.
Rock Cycle
Recommended