VOA慢速英语- 南极冰川下深层发现很多生物.docx

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1、 VOA慢速英语: 南极冰川下深层发现很多生物 1ScientistsfromtheUnitedStatessaytheyhavefoundfishandotheraquaticcreatureslivingundericywatersinAntarctica.TheymadetheaftercompletingthreemonthsofresearchattheRossIceShelf,theworld'slargestfloatingicesheet.Theresearchershopedtofindcluestoexplaintheforceofthemeltingiceandi

2、tseffectonsealevelrise.Antarcticaisthedriest,coldestandwindiestplaceonEarth.ReedSchererandRossPowellarewithNorthernIllinoisUniversityinDeKalb,Illinois.Theyjustfinisheduptheirresearchonourcontinent.MoneyfortheprojectcamefromAmerica'sNationalScienceFoundation.ProfessorsSchererandPowelldescribethei

3、rscientificinvestigation.Thecentralfocusoftheresearchwastotrytogetsomeactualphysicalconstraintsonwhattheicesheetlookslikeovertimeandwhatitisdoingrightnow.Andsowechoseastudysitewhere,inthefirstyear,wewentintothesubglaciallakeandtriedtounderstandtheenvironmentinthere,bothandintermsoftheicedynamicsabou

4、thowthelakeoperates,andhowthesedimentunderneaththeicesheetoperates,aswell,becauseit'sthewaterandthesedimentunderneaththeicethatcontrolshowfasttheiceisflowingintotheocean.RossPowellledtheinvestigation.Theteamincludedscientists,engineers,mechanicsandtechnicians.Theyusedtractorstopullelectricgenera

5、tors,sciencelaboratories,heavymachineryandothersuppliesacrosstheice.ThetractorsmovedeverythingfromthemainU.S.baseatMcMurdoStationtotheresearcher'scamp–adistanceof1,000kilometers.Thecampwasnearasubglaciallake,whereanearlierstudytookplace.Theworkedinanareacalledthegroundingzone,whereAntarcti

6、cice,landandseaconverge.RossPowellsaysthelateststudymayprovideevidencethatcanhelppredicttheeffectofclimatechangeonrisingsealevels.Whatwehavefoundisthattheseareverysensitiveareastothestabilityofhowdynamictheiceisandhowfasttheicemayreacttoincreasesofmeltingbothfromtheoceanandthe.Amongthenewinstruments

7、builtfortheprojectwasapowerfulhotwaterdrill.Theresearchersusedthedrilltodigdownsome740meters.Theycollectedwater,sedimentandothermaterialfromthegroundingzone.Workingaroundtheclockbeforethedeepholerefroze,theysentavideocameradowntothe400-square-meterunderseaarea.ReedScherersaysthevideoimagestheysawint

8、heCommandCenterwereatotalsurprise.It'saverymobileenvironment.Thebottomischangingconstantly.Andsothethingsthatwesawwereallverymobileorganisms,thingsthatswimandsomethingsthatcrawl.Andobviouslytheyaregettingenoughnutritionthattheycanthrive.Someofthelittlecrustacean-likecreaturescalledthatwesawswamq

9、uitequicklyandwerequiteactive.Thisisthefarthestsouththatfishhaveeverbeenseen.Howdidthecreaturesgethere?Whatdotheyfeedon?Andwhateffectwilltheicehaveonthem?RossPowellsaystheiceandsedimentcorestakenfromthegroundingzonecanofferclues.Weknowthattheiceismeltingthereatthemomentandsobyopeningupthecoresonceth

10、eygetback,wehopetobeabletowhattheicewasdoinginthepast,relativetowhatitisdoingnow.Andbecauseitismeltingsofastorseemstobemeltingfastatthemoment,weanticipatethattherewillbesomedifferencesthatwe'llseeinthehistoryoftheicesheetfromthesedimentcores,onceweopenthemup.RossPowellsaystheworkraisesmorequestionsthanitanswers.Togetherwithother,heisplanningtoaskforfinancialhelptocontinuestudiesofthefrozencontinent.第4页 共4页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页第 4 页 共 4 页