Environmental Literacy Framework Unit-3 Hydrosphere · PDF fileWater, which covers the...
6
Time 1 hour Materials How Does Melting Ice Affect Sea Level? Unit-3 Hydrosphere Vocabulary (Terms) Arctic Ice Loss The area covered by sea ice in the Arctic Ocean has been shrinking. For many decades, more sea ice has melted away during summers than has reformed during winters. Projections show that the ocean around the North Pole could be ice-free during summers as early as the year 2030! How might the melting of this sea ice — an area larger than the country of India — affect the rest of the world? The ice sheet on Greenland is also shrinking. Over the past 30 years, the total area of the Greenland ice sheet affected by summer melting has grown. What effect might the melting of Greenland’s ice sheet have on the rest of the world? Antarctic Ice Loss Antarctica has ice sheets on land, floating ice shelves, and sea ice surrounding it. How would the melting of these three different kinds of ice affect the rest of the world? •Transparent plastic food container, about 8” x 6” x 2” (2) •Plastic food container, about 4” x 4” (2) •Aquarium gravel (2 cups) •Overhead transparency marker •Measuring cup •Labels (2) •Colored markers •Large sheet of construction paper or poster board Environmental Literacy Framework 183 Preview Focus Questions: Ice sheet Ice shelf Sea ice If floating ice (ice shelves and sea ice) melts, will sea levels around the world rise? If land-based ice (glaciers and ice sheets) melts, will sea levels rise?
Transcript of Environmental Literacy Framework Unit-3 Hydrosphere · PDF fileWater, which covers the...
Time1hour
Materials
HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
Vocabulary (Terms)
ArcticIceLoss
TheareacoveredbyseaiceintheArcticOceanhasbeenshrinking.Formanydecades,moreseaicehasmeltedawayduringsummersthanhasreformedduringwinters.ProjectionsshowthattheoceanaroundtheNorthPolecouldbeice-freeduringsummersasearlyastheyear2030!Howmightthemeltingofthisseaice—anarealargerthanthecountryofIndia—affecttherestoftheworld?
TheicesheetonGreenlandisalsoshrinking.Overthepast30years,thetotalareaoftheGreenlandicesheetaffectedbysummermeltinghasgrown.WhateffectmightthemeltingofGreenland’sicesheethaveontherestoftheworld?
AntarcticIceLoss
Antarcticahasicesheetsonland,floatingiceshelves,andseaicesurroundingit.Howwouldthemeltingofthesethreedifferentkindsoficeaffecttherestoftheworld?
•Transparentplasticfoodcontainer,about8”x6”x2”(2)
•Plasticfoodcontainer,about4”x4”(2)
•Aquariumgravel(2cups)•Overheadtransparencymarker•Measuringcup•Labels(2)•Coloredmarkers•Largesheetofconstructionpaperorposterboard
Environmental Literacy Framework
183
Preview
FocusQuestions:
IcesheetIceshelfSeaice
Iffloatingice(iceshelvesandseaice)melts,willsealevelsaroundtheworldrise?
Ifland-basedice(glaciersandicesheets)melts,willsealevelsrise?
Activity3C-HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
Prepare
ActivitySteps:
Maketwoidenticalpiecesofice.
1.Putwaterintooneofyoursmallplasticcontainerssoitis
approximately½inchdeep.
2.Pourthewaterintoameasuringcupsoyouknowexactlyhow
muchyouhave
3.Pourthatsamevolumeofwaterintoeachofthetwosmallplastic
containersandputtheminthefreezer.
Maketwomodelsoflandandsea
1.Putalabelontheoutsideofeachofthetworectangular
containers.
2.Write“IceonLand”ononecontainerand“IceinWater”onthe
other.
3.Pour1cupofgravelintoeachcontainer.Tiltandshakeeach
containergentlysothegravelispiledinoneendtoformthe“land.”
4.Gentlypour1½cupsofwaterintoeachcontainer.Makesurethat
thewaterdoesn’tcoverthesurfaceofthegravel.
5.IntheIceonLandcontainer,placeoneofthepiecesoficeontop
ofthegravel.Nopartoftheiceshouldbeinthewater.
(Continuewithactivitystepsonnextpage.)
184
Environmental Literacy Framework
FromAntarctica'sClimateSecrets,ByLuAnnDahlman
Activity3C-HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
Whataboutabeachresort?Onthe“land”areaofyourmodel,usesmallobjectstorepresentbuildings,roads,andparkinglotsrightalongyour“beach.”Whatmighthappentoyourresortastheicemeltsineachmodel?
Ponder…
Imagineaflatbeachareawithroads,houses,andshopsjustbeyondthesand.Nowimaginehowrisingsealevels
wouldaffectyourmentalpicture.Describewhatmighthappeninyoursceneyearafteryearassealevelsrise
andwatercoversmoreoftheland.
GobacktothePreviewsectionofthisactivity.Basedonyourresults,answerthequestionsaboutseaice,
Greenland’sicesheet,andthethreetypesoficeinAntarctica.
6.IntheIceinWatercontainer,putthepieceoficeinthewater,sonopartofitissupportedbythegravel.
Waitfortheicetomelt
1.Putbothcontainersinaplacewheretheywon’tbedisturbedwhiletheicemelts.Ifit’snecessarytoleavethemformorethanafewhours,putlidsonthecontainerstokeepwaterfromevaporating.
2.Afterbothpiecesoficehavemelted,checkandmarkthewaterlevelsagain.
7.Ontheoutsideofeachcontainer,markthewaterlevel,usinganoverhead-transparencymarker.
8.Haveadiscussionwithyourteammembers:Whatdothedifferentpartsofthemodelrepresentin
therealworld?
Inthemodel,whatisthesignificanceofthewaterlevel?
185
Activity3C-HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
Practice
GottheBigIdea?
Whenicethatisfloatingintheoceanmelts,sealeveldoesnotchange.Thisappliestoallfloatingice,includingseaiceandiceshelves.Whenicethatisonlandmeltsandrunsintothesea,additionalwaterisbeingaddedtotheocean,sosealevelrises.
Getreadytopresent
Thinkofanintroductorycommentorquestionyoucanusetoexplainwhatthetwomodelsshow.
AstheicewilllikelymeltduringtheFlexhibit,youmaywanttomakeachartwithdrawingsorphotographsshowinghowthetwomodelslookbeforeandaftertheicemelts.Emphasizetheobservedchangeinwaterlevelssoyoucandrawaconnectiontochangesinsealevel.AnotheroptionwouldbetoprepareanextrasetofthemodelssothatFlexhibitattendeescanseewhattheylooklikebeforeandaftermelting.
PresentWhenyousetupyourstation,besurethatvisitorswillbeabletoseethedifferenceinwaterlevelsforthecontainerwithiceonland.Bereadytoexplainthatthewaterlevelrepresentssealevelforthewholeworld.
Forvisitorswhoareinterestedandengagedwiththeconcept,youmightsharesomeoftheestimates(below)oftheamountofsea-levelrisethatwouldresultfromthemeltingoficeindifferentplaces.
IceSheet EstimatedSea-LevelRise
Greenland 7meters
WestAntarctica 7meters
EastAntarctica 70meters
186
Activity3C-HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
Background Information for the Teacher
IceShelvesarefloatingextensionsoflandglaciersthatmovetowardthecoastsundertheweightofaccumulatingsnowandiceintheinteriorofthecontinent.Approximately44%percentofthecoastofAntarcticahasaniceshelf.Astheiceshelfadvancesovertheocean,piecesbreakoffformingicebergs.Advanceandretreatoficeshelvesisanaturalcycle,howeverin2002theLarsenBIceShelfintheAntarcticPeninsulaindicatedthattheglacierflowwasaccelerating.Formoreonthestorygotothiswebsite.
http://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php
ThetwolargesticeshelvesinAntarcticaaretheRossIceShelf(487,000sqmi/148,437.6m,2600ft/792.48mthick)andtheRonneIceShelf(430,000sqmiles/131,064m,3000ft/914.4mthick).TheRossIceShelfmovestowardtheoceanatarateofapproximately3000ft/914.4mperyear.
Whenglaciersmoveontotheoceanstheyaddvolumeandincreasesealevel.However,oncefloatingonthewater,meltingorbreakupoftheshelfdoesnotincreasesealevelrise.
Seaiceformswhenoceanwaterfreezesformingathicksolidsheetoficethatextendsawayfromtheshore.DuringtheArcticwinter,9.32millionsqm/15millionsqkmcovertheArcticOceanregionwhichshrinksto4.34millionsqm/7millionsqkminsummer.ForAntarctica,theseaiceextentrangesfrom11.8millionsqm/19millionsqkminthewinterto2.17sqm/3.5millionsqkminthesummer.Theselargeiceshelvesworktocontroltheheatexchangebetweenthepolaroceansandtheatmosphere,limittheaccessofthewaterunderneathtoreceivesunlightandincreasesthealbedooftheoceans.Theseaicereflectssolarradiationwhichhelpskeeptheplanetcool.ManyscientistsareconcernedaboutshrinkingicebecauseofitseffectonclimateaswaterabsorbssolarradiationandaddstotheEarth’sheatbudget.Packicearelargerafts(floes)oficewhichextendawayfromtheshore.About90%ofthefrozenoceanispackice.Theother10%iscalledfasticeandisattachedtotheland.Boththeseseaiceformationssupportawidearrayoflifefromdiatomstosealandwhales.
Fluctuationsinfloatingice(packice,fastice,iceshelvesandtheNorthPoleicecap)doesnotaffectsealevel.Formoreinformationonseaiceformationgotothewebsite:http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice_south.php
Glaciersarelargeamountsoflandicethatbuildupwiththeaccumulationofsnowfallingoverthousandstomillionsofyears.Undertheweightoftheiceandtheinfluenceofgravity,glaciersmovetowardthecoast.Astheglaciersmoveoverthesurfaceoftheland,theycarvelandscapes,erodeandbreakuprocks,andcarryawaytheresultingsediments.AstheEarth’sclimatechangesovergeologictime,glaciersadvanceandretreat.Inthelastfewdecadesmostoftheworld’sglaciersareretreating.DuringcoolertimesintheEarth’shistory,glacierscoveredlargepartsofcontinentsandthesealevelwaslowerthanitisnow.Astheglaciersretreatedandtheicemelted,sealevelsrose.Whenglaciersmelt,waterisreturnedtotheoceansandsealevelsrise.
Formoreinformationonglaciers,gotothewebsite:http://climate.noaa.gov/warmingworld/glaciers.htmlArrigo,K.1998.AntarcticSeaIceBiologicalProcesses,Interantionc,advariability,AntarcticResearchSeries,Vol73,p23-43
187
Activity3C-HowDoesMeltingIceAffectSeaLevel?
Unit-3Hydrosphere
188
How Does Melting Ice Effect Sea Levels
Students learn the difference in contribution to sea level rise by comparing the melting of floating ice and land ice.
NSES gr 5-8 CLEP ELF
EARTH
Water, which covers the majority of the earth’s surface, circulates through the crust, oceans, and atmosphere in what is known as the “water cycle.”
Oceans have a major effect on climate, because water in the oceans holds a large amount of heat.
The earth processes we see today, including erosion, movement of lithospheric plates, and changes in atmospheric composition, are similar to those that occurred in the past.
2B Changes in ocean circulation caused by tectonic movements or large influxes of fresh water from melting polar ice can lead to significant and even abrupt changes in climate, both locally and on global scales.
4 A. Climate is determined by the long-term pattern of temperature and precipitation averages and extremes at a location. Climate descriptions can refer to areas that are local, regional, or global in extent. Climate can be described for different time intervals, such as decades, years, seasons, months, or specific dates of the year.
4 D. Scientific observations indicate that global climate has changed in the past, is changing now, and will change in the future. The magnitude and direction of this change is not the same at all locations on Earth.
7 A. Melting of ice sheets and glaciers, combined with the thermal expansion of seawater as the oceans warm, is causing sea level to rise. Seawater is beginning to move onto low-lying land and to contaminate coastal fresh water sources and beginning to submerge coastal facilities and barrier islands.
How Does Melting Ice Affect Sea Level?
Glacier A large persistent body of ice that accumulates over time
How Does Melting Ice Affect Sea Level?
Ice sheet A large glacier or system of glaciers covering a significant part of a land mass
How Does Melting Ice Affect Sea Level?
Ice Shelf A floating sheet of ice permanently attached to a landmass.
Glossary
