ACMP ©2006-2008 UAF Geophysical Institute A-1 Permafrost: Permanently Frozen Ground

Permafrost: Permanently Frozen Ground

Overview:Students explore freezing and thawing and relate frozen water to permafrost. (NOTE: This lesson may require more than one day.)

Objectives:The student will:• freezeandthawwater;• freezeandthawsoil;• measuretemperaturewithathermometer;and• definepermafrost.

GLEs Addressed:Science• [3-4]SA1.1Thestudentdemonstratesanunderstandingoftheprocessesofsciencebyaskingques-tions,predicting,observing,describing,measuring,classifying,makinggeneralizations,inferring,andcommunicating.

• [3]SA2.1Thestudentdemonstratesanunderstandingoftheattitudesandapproachestoscientificinquirybyanswering“howdoyouknow?”questionswithreasonableanswers.

• [3]SB1.1Thestudentdemonstratesanunderstandingofthestructureandpropertiesofmatterbyclassifyingmatteraccordingtophysicalproperties(i.e.,color,size,shape,weight,texture,flexibility).

• [3]SB3.1Thestudentdemonstratesanunderstandingoftheinteractionsbetweenmatterandenergyand the effects of these interactions on systems by recognizing that temperature changes cause chang-esinphasesofsubstances(e.g.,icechangingtoliquid,waterchangingtowatervapor,andviceversa).

Vocabulary:Permafrost – permanently frozen subsoil, occurring throughout the polar regions and locally in perennially frigid areas.

Whole Picture:Permafrost is soil, semi-decomposed vegetation, a dead wooly mammoth buried in the ground, or any other material that has remained frozen for more than two years. Permafrost is a function of frigid win-ters or cold periods powerful enough to outweigh the thawing power of summers. Permafrost forms on Earthincoldplaceswhenthemeanannualtemperatureiscloseto27˚F(-3˚C)orbelow. MuchofthepermafrostinAlaskawasestablishedduringamuchcolderperiodmorethan20,000thou-sandsofyearsago,whenairtemperaturesweresocoldtheypenetrateddeepintosoil,suckingoutheatyearafteryearandleavingplaces,suchasAlaska’sNorthSlope,withfrozensoilseveralthou-sands of feet deep. People have paid attention to permafrost because of how it affects our buildings, roadways, and pipe-lineswhenitthawsandcausesthegroundtoslump.Whenkeptfrozen,permafrostprovidesastrongfoundation,butwhenice-richpermafrostthaws,settlingoccurs,bucklingroadwaysandforcingpeopleto repair unstable foundations.

Materials:• Water• Papercups(2persmallgroup)

I-II

Levels

Grades K-4

ACMP ©2006-2008 UAF Geophysical Institute A-2 Permafrost: Permanently Frozen Ground

• Soil• 3containersofdifferentshapes• Ice• Plasticbottleoraluminumcan• Scissors• Lamporotherheatsource• OVERHEAD:“SolidsandLiquids”ordisplayofvarioussolidsandliquids• STUDENTWORKSHEET:“Chilling”

Activity Procedure:Day 1

1. ShowOVERHEAD:“SolidsandLiquids”ordisplayvariousobjectstostudents.Askstudentstonamewhichitemsaresolidsandwhichareliquids.Askstudentstoexplainhowtheyknowwhichiswhich.Keepalistofstudentresponsesontheboard.

2. Explainsolidskeeptheirshape.Showstudentsseveralexamplesofsolidsfromtheclassroom.Askstudents tonameadjectivestodescribesolids.Makesurestudentsunderstandthatsolidsdonothavetobehard;theycanbesoftorfluffy.

3. Explainliquidschangebasedontheshapeofthecontainertheyarein.Showstudentshowtheshapeoftheliquidchangesindifferentcontainersbypouringamoderateamountofliquid(water)intothreeorfourdifferentlyshapedcontainers.Makesurestudentsunderstandthattheamountofliquidhasn’tchanged,onlyitsshape.Ifnecessary,marktheleveloftheliquidintheoriginalcontainerandpourtheliquidbackintoitsoriginalcontainerbetweeneachothercontainertodemonstratethatitsvolumehas not changed.

4. Askstudentswhatwillmakeasolidmelt.Listanswersontheboardorpaper.Explainheatiswhatmakesasolidmelt.Thiscanbedemonstratedbyplacingiceonaplateunderalampornearaheatsourceandinstructingstudentstowatchitmelt for30minutes,checkingitevery10minutes.Askstudents what other solids melt when they are heated. (butter, chocolate, etc.).Iftimeandresourcesallow, demonstrate melting with other substances.

5. Askstudentswhathappenswhenliquidsarecooled.Ifstudentsdonotmentionthatsomeliquidsmaybecomesolids,leadthemtothisdiscussion.(NOTE:Thiscanbedemonstratedbyplacingwaterinthefreezerandaskingstudentstoobserveitthefollowingdayafterithasfrozenormeltingchocolateandallowingittocoolandharden.)

6. Askstudentstodefinepermafrost. Ifnecessary,explainthat it ispermanently frozenground.Thismeansthegroundneverthawsormelts,eveninthesummer.Askstudentshowfrozengrounddiffersfrom non-frozen ground. (Frozen ground is hard, cold and can be used to keep things cold; non-fro-zen ground can be softer, warmer, and may be wet.)

7. Dividestudentsintosmallgroups.Filltwopapercupsforeachgroupwithsoilandaddasmall,butequalamountofwatertoeachcup.Askstudentstodescribethesoilandwatermixture.Askstudentstopredictwhatwillhappentothemixtureifitisplacedinthefreezer(ActivityProcedure9).Listallstudent ideas on the board or chart paper.

8. Place one cup from each group in the freezer.

Day 2

9. Remindstudentsoftheirpredictions.Removethesoilandwatermixturefromthefreezer.DistributeSTUDENTWORKSHEET:“Chilling”andaskstudentstodrawapictureofboththefrozenandnon-frozen mixtures and write about what they see. As a class, discuss student observations and remind students that permafrost is permanently frozen ground, or ground that is always frozen, even in the summer.

ACMP©2006-2008UAFGeophysicalInstitute A-3 Permafrost:PermanentlyFrozenGround

Extension Ideas: (1)Invitestudentstocreateacollageandwriteapoemtoaccompanyitin“ISpy”fashion.Providemagazinesandscissors,orpre-cutpicturesofliquidsandsolids,constructionpaperandglue for thecollage.Afterstudentshavefinishedtheircollage, instruct themtowriteapoem.Olderstudentscancreateariddle,suchasfororangejuiceandsocks,“Ispyaliquidthat’sorangeandsweetandasolidthat’ssmellslikemybrother’sfeet.”Youngerstudentsmayidentifytheliquidsandsolidsintheircollagewithouttheriddle,suchas“Ispysomejuice,arake,andabrush,agoose,a cake, and a plate of mush.” If appropriate, introduce or encourage rhyming. ([3-4] SB1.1) (2)Putsmallquantitiesofdifferentsubstances(e.g.,chocolate,wax,butter,icecube,cheese)intosmallplasticorfoilcontainers(suchastarttins)andstandthemorfloattheminhotwater.Askstu-dentstoobservethechanges.Dotheyallmelt?Whyorwhynot?Removethecontainersandplacethemincoldwateroronabedoficeandaskstudentstoobservethemsolidifying.Olderchildrencaninvestigatethatmaterialsmeltatdifferenttemperaturesortimehowlongittakesforeachsubstanceto melt, collecting and graphing their data. ([3-4] SB3.1)

Answers: Answers will vary.

ACMP©2006-2008UAFGeophysicalInstitute A-4 Permafrost:PermanentlyFrozenGround

Directions: Draw and describe your water and soil mixtures as direct-ed below.

1. A. Draw the water and soil mixture.

B. Describe the mixture.

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2. A. Draw the FROZEN water and soil mixture.

B. Describe the mixture.

_________________________________________

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ChillingStudent Worksheet

Name:_______________________

I-II

Levels

Solids and LiquidsOverhead

ACMP ©2006-2008 UAF Geophysical Institute Permafrost: Permanently Frozen Ground

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