VOA慢速英语- 南极冰川下深层发现很多生物.docx

VOA慢速英语: 南极冰川下深层发现很多生物 1ScientistsfromtheUnitedStatessaytheyhavefoundfishandotheraquaticcreatureslivingundericywatersinAntarctica.TheymadetheaftercompletingthreemonthsofresearchattheRossIceShelf,theworld'slargestfloatingicesheet.Theresearchershopedtofindcluestoexplaintheforceofthemeltingiceanditseffectonsealevelrise.Antarcticaisthedriest,coldestandwindiestplaceonEarth.ReedSchererandRossPowellarewithNorthernIllinoisUniversityinDeKalb,Illinois.Theyjustfinisheduptheirresearchonourcontinent.MoneyfortheprojectcamefromAmerica'sNationalScienceFoundation.ProfessorsSchererandPowelldescribetheirscientificinvestigation.Thecentralfocusoftheresearchwastotrytogetsomeactualphysicalconstraintsonwhattheicesheetlookslikeovertimeandwhatitisdoingrightnow.Andsowechoseastudysitewhere,inthefirstyear,wewentintothesubglaciallakeandtriedtounderstandtheenvironmentinthere,bothandintermsoftheicedynamicsabouthowthelakeoperates,andhowthesedimentunderneaththeicesheetoperates,aswell,becauseit'sthewaterandthesedimentunderneaththeicethatcontrolshowfasttheiceisflowingintotheocean.RossPowellledtheinvestigation.Theteamincludedscientists,engineers,mechanicsandtechnicians.Theyusedtractorstopullelectricgenerators,sciencelaboratories,heavymachineryandothersuppliesacrosstheice.ThetractorsmovedeverythingfromthemainU.S.baseatMcMurdoStationtotheresearcher'scamp–adistanceof1,000kilometers.Thecampwasnearasubglaciallake,whereanearlierstudytookplace.Theworkedinanareacalledthegroundingzone,whereAntarcticice,landandseaconverge.RossPowellsaysthelateststudymayprovideevidencethatcanhelppredicttheeffectofclimatechangeonrisingsealevels.Whatwehavefoundisthattheseareverysensitiveareastothestabilityofhowdynamictheiceisandhowfasttheicemayreacttoincreasesofmeltingbothfromtheoceanandthe.Amongthenewinstrumentsbuiltfortheprojectwasapowerfulhotwaterdrill.Theresearchersusedthedrilltodigdownsome740meters.Theycollectedwater,sedimentandothermaterialfromthegroundingzone.Workingaroundtheclockbeforethedeepholerefroze,theysentavideocameradowntothe400-square-meterunderseaarea.ReedScherersaysthevideoimagestheysawintheCommandCenterwereatotalsurprise.It'saverymobileenvironment.Thebottomischangingconstantly.Andsothethingsthatwesawwereallverymobileorganisms,thingsthatswimandsomethingsthatcrawl.Andobviouslytheyaregettingenoughnutritionthattheycanthrive.Someofthelittlecrustacean-likecreaturescalledthatwesawswamquitequicklyandwerequiteactive.Thisisthefarthestsouththatfishhaveeverbeenseen.Howdidthecreaturesgethere?Whatdotheyfeedon?Andwhateffectwilltheicehaveonthem?RossPowellsaystheiceandsedimentcorestakenfromthegroundingzonecanofferclues.Weknowthattheiceismeltingthereatthemomentandsobyopeningupthecoresoncetheygetback,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