earth’s interior and plate tectonics chapter 4. earth’s composition: not just solid rock...
Post on 16-Dec-2015
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Earth’s Composition:
•Not just solid rock
•Distinct layers
•Each layer has certain physical properties
CrustCrust►Outermost layerOutermost layer►5 – 100 km thick5 – 100 km thick►Thinnest layerThinnest layer►2 types of crust2 types of crust►< 1% of Earth’s mass< 1% of Earth’s mass
Continental CrustContinental Crust
►Average thickness Average thickness of 30 kmof 30 km
► Composition Composition similar to granitesimilar to granite
Oceanic CrustOceanic Crust►Average thickness Average thickness
from 5-8 kmfrom 5-8 km► Composition Composition similar to basaltsimilar to basalt
MantleMantle►Between crust and Between crust and corecore
►Extremely thick and Extremely thick and 67% of Earth’s mass67% of Earth’s mass
►Large amounts of Iron Large amounts of Iron and Magnesiumand Magnesium
Inner CoreInner Core►Solid and denseSolid and dense►About 6,378 km About 6,378 km below the surfacebelow the surface
►6,000 6,000 ooCelcius (hotter Celcius (hotter than Sun’s surface)than Sun’s surface)
LithosphereLithosphere
►Made of the Crust Made of the Crust and Upper Mantleand Upper Mantle
►RigidRigid►About 150 km thickAbout 150 km thick
AsthenosphereAsthenosphere
►Part of the mantlePart of the mantle►Made of rock Made of rock (molten)(molten)
►Flows like putty Flows like putty (very viscous)(very viscous)
Tectonic PlatesTectonic Plates
►Rigid, solid rockRigid, solid rock►Move around on Move around on AsthenosphereAsthenosphere
►Jigsaw puzzleJigsaw puzzle
Some plates Some plates contain both contain both continentalcontinental and and oceanicoceanic
crustcrust
How do we How do we know what the know what the Earth’s interior Earth’s interior
looks like?looks like?
Deepest hole Deepest hole drilled:drilled:
►12.2 km into the 12.2 km into the earthearth
►Kola Pennisula, Kola Pennisula, Russia 1984Russia 1984
Seismic WavesSeismic Waves►From earthquakesFrom earthquakes►Travel through Travel through earth layersearth layers
►Speed depends on Speed depends on density of materialdensity of material
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