A Layered EarthSlide 2Evidence from EarthquakesSlide 4Slide 5Slide 6Slide 7Slide 8Lithosphere and AsthenosphereContinentsSlide 11Slide 12Slide 13Slide 14Continental DriftSlide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Slide 62Slide 63Slide 64Slide 65Slide 66Slide 67A Layered Earth•Solid inner core- 6,370 km deep•Liquid outer core- 2,900 km deep•Mantle – 100-200 km deep•Brittle crust- Surface to 100-200 kmEvidence from Earthquakes•Two Types of Seismic Waves–P Waves: Compressional–S Waves: Transverse•Seismic waves do not travel at the same speed through the earth •S Waves cannot pass through liquid–Shadow zone develops behind the liquid core•P Waves slow down through liquidLithosphere and Asthenosphere•Lithosphere (litho=rock)–100-200 km thick–Oceanic and Continental Crust•Asthenosphere (asthenes=week)–Below Lithosphere to 350-650 km–Hot, partially liquid upper part of the MantleContinents•Continents are made of low density crust rock (like granite) that floats on denser crust•Oceanic crust is more dense than continental crust so it sits lowerContinental Drift•Continents look like they fit together–S. America and Africa•1912-Alfred Wegener proposes that continents move. –Everyone thought he was nuts•1960- Seafloor
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