地球物理基础第一次课件

SomeofthesePPTslidesareaftermaterialsbyLowrieW,LillieRJ,NiuF,ZengR,ShiY,ZhangS,andsomeothercontributors.bySomeofthesePPTslidesareaftermaterialsbyLowrieW,LillieRJ,NiuF,ZengR,ShiY,ZhangS,andsomeothercontributors.byWEIDSeptember9, RequiredmendedGrading:isweightedas1.finalexam(30%),Mid-termexam isdueisdue2weeksafteritis willnotbeacceptedtwoweeksafterthedeadline. willbepenalized:80%-10%(1daylateto7daylate).ItisOKtodiscuss witheachother,andtogiveoraccepthelp,butleaveitatthat.Idon’twanttoseeexactcopiesandIwillexpectyoutobeabletoreproducewhateveryoudidduringatest!AttendanceLackofattendancewillbepunished-10%inOutlineofOutlineofAnappreciationofthelevelofcurrentknowledgeingeophysics,andthemanyexcitingproblemsthatstillremaintobetackled.UnderstandingtheEarth’scompositionanddynamics,andtheirrelationshipswiththesurfacegeologicalphenomena,usingthemeansofphysics.学重力学地磁学地热学现代大地测量学 间3week2014/9/16, 5week2week2014/9/9,4week2014/9/23,6week2014/10/7,5week2014/10/1NationalDay9week2014/10/28,8week2014/10/21,7week2014/10/14, CGU2014 10week11week2014/11/11, 13week2014/11/25,10week12week2014/11/18, 14week2014/12/2,15week2014/12/9, 16week2014/12/16,16week 17week17week2014/12/2518weekEndGeology+Geology+(1)ForwardGeophysicalGeophysicalMethods:(2)EarthasMassM=6x1027RadiusR=6371InteriorofInterioroftheMoreDetailsaboutUnderUnderofA.EarthasanElastic the theu x1x dq(tR 43RRProbingtheProbingtheEarthwithSeismicWaveWhatWhatcanwelearnonearth’sstructurefromseismology?Iasp91ModelSeismicWave--RichardFeynman,TheFeynmanLecturesonPhysics,3DSeismicVelocity 龙门山断裂带中-南段:1657-4-21汶川1958-2-8北川1970-2-24大邑西龙门山断裂带北东段无M6相邻的松潘-平武地区 6.0— 重新定位的M2.8级余震资料由冲断层带结构在余震带的南、中段清冲断层带结构在余震带的南、中段清—逆断层型破裂段的余震带宽度大，走滑型破裂的余震带宽度小 PPk4v SRayleighRayleighLoveWaveaninterfactwavehorizontalmotion ImperialImperialValleyOctober15,EarthquakeFaultsteSeismicitySeismicity(2)–DepthGlobalNuclearGlobalNucleard~sinxcd~sinjxL)Ljc:eigenvalueorLLoscillation=stationaryInterferenceoftwocounterpropagatingd(x,t)AU(x,FourSpheroidalSpheroidalnormalmodes:S:«balloon»«breathing»:radialonlyS:«football»S(25.7S(4.5Rem:S=Seismicnormal GravityGravityField2V1(r2V)1 (sinV) V0r2r r2sin r2sin2OnlykeepitemtoGMGMa V (3sin1) WhereJCA2OntheotherV'r[1P(cos3 aV[1J()nP(cos)()n(CmcosmSm r Bathymetry,TopographyandGeoidGeoid&MassTheShapeTheShapeoftheEarth,TheAveraged地地fyEarth’sMagneticXFcosIcosYFcosIsinZFsinF(X2Y2Z2Darctan(YXIZX2Y) W hsinm)()Rr (jcosmksinm)()P(cosrRV [1J()P(cos)( (CcosmSsinm)P(cosR RrrrInairbornemagneticsurveyingtheInairbornemagneticsurveyingthemagnetometermaybemountedrigidlyontheairneattheendofaboom(A),ortowedinanaerodynamichousingbehindthene(B).Inmarinestudiesthemagnetometermustbetowedsomedistancedbehindtheshiptoescapeitsmagneticfield.Apairofsensitivemagnetometersinthesameverticalneactasamagneticgradiometer(afterSlacketal.,1967). PolarPolarWanderPath&ContinentHeatFlowandExternalheat qdsqdvq(dxdydzInternalheat A(dxdydzTq(dxdydz)A(dxdydz(dxdydz)cTAq;qcTAk2TTk2T k,isknownasthethermaldiffusivitOceanicOceanicHeatFlow,t1/2,t-1/2AgeMeanDepthofThicknessofOceanicHeatSlabsInthisviewofaflattened-outmantlefromthenorthwest,theblueblobsshowwherecolder,densermaterialissinkingintothemantle.Nearthesurface,mostofthecoldermaterialisintheancientrootsofcontinentalcratons.Subductingslabsofoceaniclithospherealsoappear,beingrecycledintothemantlefromlumesInthisviewfromtheouthwesttheredblobsarewarmerplumesoflessdensematerial,risingprincipallyintoheocean-ridgespreadingenters.AhugeplumeseemstoefeedingspreadingattheEastacificRisedirectlyfromthere.Mostoftheheatbeingeleasedfromtheearth'snterioremergesatthefast-preadingEastPacificRise. te te GPSGPSLayeringbyChemical柯石英柯石英Sedimentary