Compositional Layersdivided into 3 layers based on elements that

make up each layer

CRUST•Outermost, solid layer•Made mostly of oxygen, silicon, and aluminum•Divided into two types:

1.Continental Crust•Less dense•Thicker (30-100 km)•Under continents

2.Oceanic Crust•Denser (2x more iron, calcium, and magnesium)•Thinner (5-20 km)•Under ocean

MANTLE•Convection occurs in this layer!•Layer between crust and core•2,900 km thick•Contains about 2/3 of Earth’s mass (67%)•Mostly made up of magnesium•Solid but acts like a liquid (like asphalt or

chewed gum)

CORE•Densest layer•Made of iron and nickel•Extends from mantle to center of Earth•Radius of 3,430 km (diameter = 6,860 km)•About 1/3 of Earth’s mass (33%)

Physical Layersdivided into 5 layers based upon different

physical properties

LITHOSPHERE•Solid, rigid outermost layer•Crust and upper mantle•15-300 km thick•Divided into pieces called tectonic platesASTHENOSPHERE•Middle mantle•Solid but acts like a liquid (plastic-like)•Convection – allows movement of tectonic plates •250 km thickMESOSPHERE•Lower mantle, beneath asthenosphere•Solid, liquid-like rock flows slower•2,550 km thick

OUTER CORE•Between mesosphere and inner core•Only liquid layer!•Made up of iron and nickel•Convection – creates Earth’s magnetic field•2,200 km thick

INNER CORE•Innermost, densest layer•Pressure causes it to be solid •Made up of mostly iron and some nickel •Radius = 1,230 km (diameter = 2,460 km)