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EnvironmentWatersheds17TuesdayOctober820132013FireServiceMeritAwardsEveryyearduringFirePreventionWeekwerecognizeindividualThe2013awardrecipientsareScottWhitmoreIndividualAwardYellowknifeFireDepartmentHayRiverFireDepartmentNWTdriftwoodstudymakeswavesingeologyworldByMEAGANWOHLBERGDriftwoodalongtheshoresofGreatSlaveLakeisnotonlymorphingthegeologyoftheareabutgeologistsunderstandingofhowwoodcarriedbyiceandwaterisusedtocon-structlandforms.FindingsstemmingfromongoinggeologicalresearchonthebaysofGreatSlaveLakenearFortResolutionhavehelpedcoinanewtermbeingusedbygeolo-giststodescribethewayinwhichdriftwoodbuildsupovertimetoformislandsandbuildbiggershorelines.Driftcretion-acom-binationofdriftwoodandaccretion-isanewtermdevelopedbyUniversityofColoradoPhDstu-dentNatalieKramerAn-dersonwhoseNationalGeographic-fundedre-searchhasbroughthertotheNorthwestTerritoriesforthelasttwoyearstostudythemovementandvolumeofdriftwooden-teringtheterritoryviaitsriversystems.Thewordwhichwillbepre-sentedforthersttimeattheGeologicalSocietyofAmer-icameetingthismonthde-scribesthewaythatdriftwoodcobbleandbouldersbecomenewlandastheyarepushedupontotheshoreorintois-landformsovermanyyearsbyiceandwaterandcomesfromherresearchintowherewoodgoesonceitentersGreatSlaveLake-researchthatwonhertheawardforbeststudentproposalingeomorphologyintheUSthisyear.WooddeliveredfromtheSlaveRiverstaysinthelakeandcontributestolandgrowthAndersonsaid.Whatweretalkingaboutherearedriftcretionswherebigwoodmatsorwoodbermsgetshovedupontheshorelinesandthenstaythereperma-nentlyandwhathappensistheyallownewtreestogrowandtheneventuallythelandgrowsoutwards.LookingattwoislandsnearFortResolution-PauletteIs-landandMooseDeerIsland-Andersonfoundthatthesoilontheislandwasstrictlytheproductofdecomposedwood.Ifyoudigintoanyofthesoilsonthoseislandsthereisntanysoil.Itsstraightorganicmatterdowntocob-ble.Usuallywhenwetalkaboutsoilswetalkabouttwothingsmineralsoilsandorganicmaterials.Mineralsoilswouldberockswhentheyweather...Buttheorganicmatterisjustthedecayedlogsandleaflitter.Surveysofthelakeshoresdonefromairplaneandseakayakalsoclearlyrevealedthedriftcretionprocesshigh-lightingtheconstantgrowthofthelakeshoreshesaid.Youcanseetheselinearlinesoftreesthatcorrespondtothesedecayinglinesofwood.ItisreallyneatAndersonsaid.Beforetheforestmaturesfortherst100metresorsofromtheshorelineyoucanseetheselinesoftreesthatprobablycorrespondtotheselinesofolddriftwoodthathavebeenthrownuponshorebytheiceorlaketsunamis.Shesaiddriftcretionwilllikelycausethelakewhichwascarvedoutbyglaciersandbuiltonbedrocktoshrinkovertime-albeitaverylongtime.TheSlavesbeenthrowingalotofsedimentintothelakeandwood.ThatsprobablywhytheSouthShoressoshallowwhiletheEastArmssodeep.AlloftheriversdrainingintotheEastArmarentreallycar-ryinganysedimentorwoodbecausetheydrainoutoftheCanadianShieldandtheresjustnotalotoftreestopplingshesaid.Andersonsaidthelakeservesasanimportantbasinforcleaningdebrisandpo-tentialtoxinsoutoftherivers.TheGreatSlaveLakeiskeepingthewaterandthesedimentintheMackenzieRivercorridorreallyclean.CamerassetuponriversystemAndersonsresearchonthelakecoincideswithandisaidedbyanotherbranchofworkshesbeencarryingoutusingtimelapsephotog-raphyatvarioussitesonriv-ersthroughouttheNWTin-cludingtheMackenzieSlaveLiardHayandPeelRivers.PhotographstakenontheMackenzieatFortProvidenceusingacameraplantedthereallwinterconrmedAnder-sonshunchthatmostdrift-woodremainstrappedinthelakewhilethesmallamountthatsexporteddownriverismostlyduetoicebreakup.Thoughitstooearlytoidentifysolidtrendsontheriversystemsobser-vationssofarhaveallowedhertoconcludethatwoodtransporthitsamaximumthresholdtimedwiththehighestpeakofwatervol-umeeachyearataround4500m3s.BasedonherphotosfromthisspringontheSlaveandLiardRiversshesaidshesabletoidentifyagapofap-proximatelyonedaybetweentheicejamoodandalargepulseofwoodcomingdownriveraswell.Preliminaryresultsfromthetimelapsephotography-anewmethodologyshedevel-opedtoestimatevolumesofwoodbeingtransporteddownriver-willalsobepresentedattheAmericanGeophysicalUnionmeetinginSanFran-ciscoinDecember.Andersonsaidtheresearchasitunfoldsoverthenextseveralyearscouldhaveim-portantimplicationsforthoseconsideringhydrodevelop-mentontheSlaveorotherriversintheNWT.Thatstoryisgoingtobereallyinterestingtoanyonestudyingthedeltasandany-onewhosinterestedinwhatcoulditdoifyoublockallthiswoodshesaid.WhatifyouseveredthisarteryofwoodbeingdeliveredtothelakeWhatroledoesthatwoodplayaroundthelakemarginsIthinkitsareallybigone.PhotocourtesyofNatalieKramerAndersonGeologistNatalieKramerAndersontakestreecoresamplesfromdriftwoodpiledalongtheshoresofGreatSlaveLake.