Unit 2 lesson 1 science fusion workesheets
- 1. What are Earth’s five mainoceans? Almostthree-fourthsof Earthiscoveredbyoceanwater.On a map, the continentsappearas huge islandssurroundedbyavastglobal ocean.Earth’sglobal oceanisdividedintofive main oceans.Indecreasingorderof size,theyare the PacificOcean,AtlanticOcean,IndianOcean, SouthernOcean,andArctic Ocean. The chemical characteristicsof oceanwaterinclude salinity,orthe amountand type of dissolvedsalts.Chemical characteristicsalsoinclude the amountandtype of gasesinthe seawater.The physical characteristicsof oceanwaterinclude temperature anddensity. The overall salinityof seawaterisabout3.5 percent.Dissolvedsaltscome fromwaterflowing on or underEarth’ssurface,and fromunderwatervolcanoesandvents.The salinityof seawater has remainedrelativelysteady,butitvariesfromplace toplace dependingonthe entryof freshwaterstreams,precipitation,andrate of evaporation. The ocean has three temperature layersbydepth.The toplayer,or surface zone,isthe warmestlayer.Inthe nextlayer,the thermocline,watertemperature dropswithincreased depthfasterthanit doesinotherlayers.The deepzone isthe deepestlayerandthe coldest. By latitude,surface wateriswarmestnearthe equator andcoldestnearthe poles.Byseason, surface wateriswarmestin summerandcoldestinWinter. Densityis a measure of the mass of a substance dividedbyitsvolume.The densityof ocean waterdependsontemperature andsalinity.Saltwaterisdenserthan freshwaterbecause salt watercontainsa largeramount of dissolvedsolids.Temperature affectsthe densityof ocean watermore than salinitydoes.Coldwaterisdenserthanwarmwater. How isthe ocean floorstudied? To learnaboutthe oceanfloor,scientistsuse technologysuchassonar,drills,underwater explorationvessels,andsatellites. 1.Sonar, whichstandsfor soundnavigationandranging,usessoundwavestomeasure distances. Sonardatacan be usedto make mapsof the oceanfloor. 2.Satellitescan measure variationsinthe heightof the ocean’ssurface.The oceanfloor’s featurescanaffectthe heightof the waterabove them. To explore the oceans,scientistsuse 3.underwatervessels,some of whichhave pilots and researchers. With 4.Deep-Seadrilling scientistscandrill andcollectcores,or longtubesof rock and sediment,fromthe seafloor. What are the two main regionsof the ocean floor? The two mainregionsof the oceanfloor are the continental marginandthe deep-oceanbasin. The continental margin isthe edge of the continentthatiscoveredbythe ocean. The continental marginisdividedintothe continental shelf,the continental slope,andthe continental rise.
- 2. The deep-oceanbasinbeginsatthe endof the continental marginandextendsunderthe deepestpartsof the ocean.The deep-oceanbasinincludesnarrow depressionsandflat, smoothplains. Whatare the featuresof the ocean floor? A long,underseamountainchainthatformsalongthe floorof the oceanis calleda mid-ocean ridge.Mid-oceanridgesoccurat the boundariesof Earth’stectonicplates,whereplatesmove apart fromeach other.Thismotioncreatesacrack in the oceanfloorcalledarift,allowinghot magma to move upwardthroughthe riftand cool to form new rock. The large,flat,almostlevel areaof the deep- oceanbasiniscalled the abyssal plain.Thisarea iscoveredwithlayersof fine sediment. A long,narrow depressioninthe deep-oceanbasiniscalledan oceantrench.It formswhere one tectonicplate subductsanotherplate. Volcanoesandearthquakesare commoninandalongsubductionzones. Submergedvolcanicmountainsonthe oceanfloorare called seamounts. Theymay format tectonicplate boundariesandalsofarfromplate boundariesoverplaces calledhotspots ( magma). If a seamountgrowsabove sealevel,itbecomes avolcanic island. Workshop5 1.Write the definitionsofthe followingwords: salinity,deepoceanbasin,mid-ocean ridge,Oceantrench,Thermocline,continental margin 2.)What’sare the three characteristics of ocean water? b) How is the oceanfllor studied?Define the four ways to do it . c)What are the two main regions of the ocean floor? Workshop6 1.Match the featuresofthe ocean floor with theirdefinitions.
- 3. Term/feature of the ocean floor Definition a) Mid-oceanridge_________ 1) The large,flat,almostlevelareaof the deep- oceanbasin b) the abyssal plain.____________ 2) A long,narrow depressioninthe deep- oceanbasin C) Ocean trench________________ 3) A long,underseamountainchainthat formsalongthe floorof the ocean d) seamounts_________________- 4) A seamount that growsabove sealevel, e) Volcanic island_________________- 5) Submergedvolcanicmountainsonthe oceanfloor 2.Fill the blanks with the right words from the box. hot magma crack Tectonic plates rift move apart A.Dad, howcan Mid-oceanridgesform? B. At the boundaries of the Earth’s__________________, where plates _______________- ___________________-from eachother.Thismotioncreatesa_______________in the ocean floorcalleda____________, allowing __________________ to move upwardthroughthe rift and cool to formnewrock. A.Thanksdad,you’re sowise!