ACMP ©2006-2009 UAF Geophysical Institute Vanishing Coast: Erosion

Vanishing Coast: Erosion (modified for ADEED)

Overview:Students learn about erosion by observing two classroom demonstrations and listening to an Elder share local history.

Objectives:The student will:• identifyerosionfromaseriesofpictures;• listenrespectfullytoanElder;and• relateinformationfromastory.

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

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

[4]SA2.1Thestudentdemonstratesanunderstandingoftheattitudesandapproachestoscientificinquiry by supporting the student’s own ideas with observations and peer review.

[4]SD2.1ThestudentdemonstratesanunderstandingoftheforcesthatshapeEarthbyobservingmodelsofhowwaves,wind,water,andiceshapeandreshapetheEarth’ssurfacebyerodingrockandsoil.

Whole Picture:Alongtimeago,peopleonAlaska’scoast livedindifferentplacesdependingontheseason.Theywouldhavedifferentcampsalongthecoastlinethatweregoodspotstocatchfish,seals,walrus,orwhales.Whentheyweredonefishing,theywouldmove,oftentoamoreshelteredareaawayfromtheocean.Not long ago,most villagers decided to live in one place,where stores, post offices, andschoolswerelocated.Someofthesevillageswereonthesitesofoldcamps,oftennexttothewater.InplaceslikeShishmaref,villageswerebuiltonislandsmadeofsand,sometimeswithacoreoffrozensandandice.Whenhighwindsfromstormswhipuptheocean,bigwavescancrashintotheshore,erodethesandyshorelineandthawfrozengroundunderneath.InShishmaref,thishascausedsomehousestotipintotheocean(whennobodywasinside).VillagersofShishmarefandothervillagesarenowthinkingofmovingfartherfromtheocean,butitwillbeexpensivetodoso.Somethinkthatstormshittingtheirvillagesareworsenowbecauseseaiceformslaterandmeltsearlierthanitusedto.

Materials:• Plasticbottle,1-literorlarger• Beaker• Aluminumroastingpan• Soil• Water• 2styrofoamcups• MapofAlaska• STUDENTWORKSHEET:“Erosion”

ACMP ©2006-2009 UAF Geophysical Institute Vanishing Coast: Erosion

Vocabulary:erosion-theprocessofwearingawaybytheactionofwater,wind,orglacialice

Teacher’s Note: CoastalerosionaffectsAlaska’scoasts,residents,structures,andwildlife.AwarmingArcticisimpactingtherateoferosionalongAlaska’scoast.Seaice,whichonceprotectedthecoastsfromfallstorms,islesspresentinthefallmonthsthanitoncewas.Withouttheice,waves crash directly onto the beaches, increasing erosion. Several coastal communities have used seawallsandotherman-madebarrierstoholdbackerosion;however,thesemeasuresareonlytemporary, since wind and waves wear away these barriers as well as the coastline.

Activity Preparation:1. Invite a local Elder to visit the classroom and share with students how

the coastline has changed physically in their memory.2. PreparesnacksandbeveragesfortheElderandmakesureheorshe

hasadequatetransportationtoandfromtheclassroom.3. Laytheplasticbottleonitssideandcutasectionfromitsothatitforms

atrough.Fillthebottomofthebottlewithsoil.4. Punchseveralholesinthebottomofoneofthestyrofoamcupsandfill

the other one with water.5. Fillonesideoftheroastingpanwithsoilorsand.

Activity Procedure:1. ShowstudentsamapofAlaska.Ifnecessary,explainthebluepartsofthe

map represent water (ocean, lakes, rivers, etc.) and the other colors rep-resent land.

2. Explaineachdoton themaprepresentsacity.Askstudentshowmanypeoplelivebytheocean.ExplainmostofAlaska’sresidentsliveneartheoceanandrelyontheoceanforfoodandothermaterials.

3. Askforastudentvolunteer.Holdthebottleatanangle(lessthan45°)sothespoutisfacingdownward.Placeabeakeratthebottomofthespouttocatchrunoff.Makesurethecapisoff.

4. Instructthestudenttopourwaterslowlyintothebottleforseveralminutes.The student will need to position the cup with holes over the bottle, then pourthewaterintothecup.Afterthebeakerishalffullwithwater,stopandaskstudentswhathappened.

5. Askstudentsifthesoilwashedoffwiththewater.(yes)Howcantheytell?(The water should be dark-ened from the soil.)

6. Askstudentsiftheyknowwhaterosionis.ExplainerosionistheremovalofdirtandsoilfromEarth’ssurfacebywaterandwind.Erosionatthecoastisthemostdramatic,changingthebeacheveryday.

7. Explainerosionalongthecoastwearsawaythebeach.Aswaterwashesagainstthebeachitslowlyerodes,orwearsaway, thebeach,changing thecoastline.Sea icehasprotected thebeach frommuchofthiserosion.However,seaicealongthecoastisappearinglessandlesseachyear,resultingin more and more erosion.

8. Remindstudentsthisprocessofsoilwashingawaywithwater iscallederosion;watererodesthebeachwiththeactionofwaves.

9. Placethealuminumroastingpanfilledwithdirt inacentral locationsoallstudentscanwatchthedemonstration.Pourafewinchesofwaterintheoppositesideofthepan.

ACMP ©2006-2009 UAF Geophysical Institute Vanishing Coast: Erosion

10. Tiltthepanbackandforthsothewaterformssmallwavesagainstthesoil.Askstudentsifthesoilerodes (it may or may not).Continuetiltingthepan,butfaster,sothewavessplashfasteragainstthesoil.Askstudentstodescribewhatchanged.Didthesoilerodefasterormorethanthefirsttime?(yes)Asaclass,discussthedifference.

11. WelcomeandintroducetheEldertotheclassroom.Explainstudentsarelearningabouterosion.In-vitetheEldertosharestoriesofhowthecoastshavechangedasaresultoferosions,storms,andhuman activity.

12. ThanktheElderforhisorhertime.13. AskstudentstorecallsomeofthethingstheEldertoldthem.Liststudentideasontheboard.14. DistributetheSTUDENTWORKSHEET:“Erosion”andassiststudentsasnecessary.AskGradeK-2

students to dictate their answers to Question 2 to an older student or classroom aide.

Answers:

STUDENT WORKSHEET: “Erosion”

1. A(removalofsoilandsandfromEarthssurfacebywater and wind)

2. B

3. Answers will vary.

ACMP ©2006-2009 UAF Geophysical Institute Vanishing Coast: Erosion

1.Whatiserosion?A. removalofsoilandsandfromEarth’ssurfacebywaterandwindB. rainandstormsC. using machines to dig a ditch

2.Circlethesetofpicturesthatshowserosion.

A. B.

C.

3. Describe one thing the Elder said has changed along the coast.

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ErosionStudentWorksheet