世界地理-地球的结构与板块构造英文版

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1、TheStructureoftheEarthandPlateTectonicsStructureoftheEarthTheEarthismadeupof3mainlayers:CoreMantleCrustInnercoreOutercoreMantleCrustTheCrustThisiswherewelive!TheEarth’scrustismadeof:ContinentalCrustthick(10-70km)-buoyant(lessdensethanoceaniccrust)-mostlyoldOceanicCru

2、st-thin(~7km)-dense(sinksundercontinentalcrust)-youngHowdoweknowwhattheEarthismadeof?Geophysicalsurveys:seismic,gravity,magnetics,electrical,geodesyAcquisition:land,air,seaandsatelliteGeologicalsurveys:fieldwork,boreholes,minesWhatisPlateTectonics?Ifyoulookatamapoft

3、heworld,youmaynoticethatsomeofthecontinentscouldfittogetherlikepiecesofapuzzle.PlateTectonicsTheEarth’scrustisdividedinto12majorplateswhicharemovedinvariousdirections.Thisplatemotioncausesthemtocollide,pullapart,orscrapeagainsteachother.Eachtypeofinteractioncausesacha

4、racteristicsetofEarthstructuresor“tectonic”features.Theword,tectonic,referstothedeformationofthecrustasaconsequenceofplateinteraction.WorldPlatesWhataretectonicplatesmadeof?Platesaremadeofrigidlithosphere.Thelithosphereismadeupofthecrustandtheupperpartofthemantle.What

5、liesbeneaththetectonicplates?Belowthelithosphere(whichmakesupthetectonicplates)istheasthenosphere.PlateMovement“Plates”oflithospherearemovedaroundbytheunderlyinghotmantleconvectioncellsPracticalExercise1Supercontinents!Whathappensattectonicplateboundaries?DivergentCon

6、vergentTransformThreetypesofplateboundarySpreadingridgesAsplatesmoveapartnewmaterialiseruptedtofillthegapDivergentBoundariesAgeofOceanicCrustCourtesyofwww.ngdc.noaa.govIcelandhasadivergentplateboundaryrunningthroughitsmiddleIceland:AnexampleofcontinentalriftingTherear

7、ethreestylesofconvergentplateboundariesContinent-continentcollisionContinent-oceaniccrustcollisionOcean-oceancollisionConvergentBoundariesFormsmountains,e.g.EuropeanAlps,HimalayasContinent-ContinentCollisionHimalayasCalledSUBDUCTIONContinent-OceanicCrustCollisionOcean

8、iclithospheresubductsunderneaththecontinentallithosphereOceaniclithosphereheatsanddehydratesasitsubsidesThemeltrisesformingv