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时间：2024-01-05 06:38:15 下载该word文档
文档来源为:从网络收集整理.word版本可编辑.欢迎下载支持.Passage1EveryonehasheardoftheSanAndreasfault圣安德烈亚斯断层（断层）,whichconstantly不断的，时常threatensCaliforniaandtheWestCoastwithearthquakes.ButhowmanypeopleknowabouttheequallyseriousNewMadridfaultinMissouri?同样严重的新马德里断层在密苏里BetweenDecemberof1811andFebruaryof1812,threemajorearthquakesoccurred,allcenteredaroundthetownofNewMadrid,Missouri,ontheMississippiRiver.Propertydamagewassevere.财产损害是严重的Buildingsintheareawerealmostdestroyed.Wholeforestsfellatonce,andhugecracksopenedintheground,allowingsmellofsulfur（硫磺）tofilterupward.TheMississippiRiveritselfcompletelychangedcharacter,性格developingsuddenrapidsandwhirlpools.急流漩涡Severaltimesitchangeditscourse,andonce,accordingtosomeobservers,itactuallyappearedtorunbackwards.FewpeoplewerekilledintheNewMaridearthquakes,probablysimplybecausefewpeoplelivedintheareain1811;buttheseverityoftheearthquakesareshownbythefactthattheshockwavesrangbellsinchurchtowersinCharleston,SouthCarolina,onthecoast.BuildingsshookinNewYorkCity,andclockswerstoppedinWashington,D.C.ScientistsnowknowthatAmerica'stwomajorfaultsareessentiallydifferent.本质上不同TheSanAndreasisahorizontalboundary一个横向边界betweentwomajorlandmassesthatareslowlymovinginoppositedirections.Californiaearthquakesresultwhenthemovementofthesetwomassessuddenlylurches（倾斜）forward.TheNewMadridfault,ontheotherhand,isaverticalfault垂直的;atsomepoints,possiblyhundredsofmillionsofyearsago,rockwaspusheduptowardthesurface,probablybyvolcanoesunderthesurface.Suddenly,thevolcanoescooledandtherockcollapsed,leavinghugecracks.Evennow,therockcontinuestosettle垂直的downwards,andsuddensinkingmotionstrigger（触发）earthquakesintheregion.Thefaultitself,alargecrackinthislayerofrock,withdozensofothercracksthatsplitofffromit,extendsfromnortheastArkansasthroughMissouriandintosouthernlllinois.ScientistswhohavestudiedtheNewMadridfaultsaytherehavebeennumeroussmallerquakesintheareasince1811;thesesmallerquakesindicatethatlargeronesareprobablycoming,butthescientistssayhavenomethodofpredictingwhenalargeearthquakewilloccur.1.ThispassageismainlyaboutC.A.theNewMadridfaultinMissouriB.thecausesoffaultsC.theSanAndreasandtheNewMadridfaultsD.currentscientificknowledgeaboutfault2.TheNewMadridfaultisA