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 Made of up several layers  Studied in two ways:  Composition (elements)  Physical properties (temperature, density)  Three Physical layers  Crust (least dense material)  Mantle  Core (most dense material)

 Properties include temperature, density, and ability to flow  Five layers:  Lithosphere  Asthenosphere  Mesosphere  Outer Core  Inner Core

 Outermost, rigid layer  “Rock sphere”  Two parts  Crust  Rigid upper part of mantle  Divided into pieces called tectonic plates

 Soft layer of mantle  “Weak sphere”  Solid rock that flows very slowly (like putty)  About same rate that your fingernails grow  Pieces of lithosphere move on top of this layer

 Strong, lower part of mantle  “Middle sphere”  Extends from bottom of asthenosphere down to Earth’s core  Differences in density and rigidity from asthenosphere

OUTER COREINNER CORE  Liquid layer  Lies beneath mantle and surrounds inner core  Temperature range from 4,400 to 5,100 °C  Outer  Inner  Convection of liquid metal results in Earth’s magnetic field  Solid, dense center of planet  Bottom of outer core to center of planet  Temperature ranges from 5,100 to 6,200 °C  Discovered through use of earthquake generated seismic waves

 Outermost layer  Thinnest layer also  Two types of crust:  Continental (granite-like)  Oceanic crust (basalt-like)  Denser than continental  Layer we know most about

 Layer between crust and core  Extremely thick  Contains most of Earth’s mass  Too deep to drill to  Underwater volcanoes serve as “windows”

 Layer below the mantle to center of Earth  Composed mostly of iron (Fe) and smaller amounts of nickel (Ni)  Makes up about 33% of Earth’s mass