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Yourwebbrowser(Safari7)isoutofdate.Formoresecurity,comfortand thebestexperienceonthissite: Updateyourbrowser Ignore S O U T H A M E R I C A: P H Y S I C A L G E O G RA P H Y Forthecompleteencyclopedicentrywithmediaresources,visit: http://www.nationalgeographic.org/encyclopedia/south-america-physicalgeography/ SouthAmerica,thefourth-largestcontinent,extendsfromtheGulfofDariénin thenorthwesttothearchipelagoofTierradelFuegointhesouth. SouthAmerica’sphysicalgeography,environmentandresources,andhuman geographycanbeconsideredseparately. SouthAmericacanbedividedintothreephysicalregions:mountainsand highlands,riverbasins,andcoastalplains.Mountainsandcoastalplains generallyruninanorth-southdirection,whilehighlandsandriverbasins generallyruninaneast-westdirection. SouthAmerica’sextremegeographicvariationcontributestothecontinent’s largenumberofbiomes.Abiomeisacommunityofanimalsandplantsthat spreadsoveranareawitharelativelyuniformclimate. Withinafewhundredkilometers,SouthAmerica’scoastalplains’drydesert biomerisestotheruggedalpinebiomeoftheAndesmountains.Oneofthe continent’sriverbasins(theAmazon)isdefinedbydense,tropicalrainforest, whiletheother(Paraná)ismadeupofvastgrasslands. Withanunparallelednumberofplantandanimalspecies,SouthAmerica’srich biodiversityisuniqueamongtheworld’scontinents. 1of9 Mountains&Highlands SouthAmerica’sprimarymountainsystem,theAndes,isalsotheworld’s longest.Therangecoversabout8,850kilometers(5,500miles).Situatedonthe farwesternedgeofthecontinent,theAndesstretchfromthesoutherntipto thenorthernmostcoastofSouthAmerica.Therearehundredsofpeaksmore than4,500meters(15,000feet)tall,manyofwhicharevolcanic. ThehighestpeakintheAndes,Aconcagua,standsat6,962meters(22,841feet) andstraddlestheArgentina-Chileborder.Aconcaguaisthetallestmountain outsideAsia. HighplateausarealsoafeatureoftheAndes.ThealtiplanoofPeruandBolivia, forexample,hasanelevationofabout3,700meters(12,300feet).The PatagoniaregionofArgentinaandChileconsistsoflower-elevationplateausand ruggedglaciers. Mostplantsinthealpinebiomearesmall,andtheirleavesarestiffandstrongto protectthemfromfrostanddrought.Thelargestherbintheworld,Puya raimondii,isknownastheQueenoftheAndes.APuyaraimondiicanlivefor100 yearsandcangrowtomorethan9meters(30feet)tall.Theleavesofthis endangeredspeciesallgrowfromonewoodystem,allowingmoisturetorun downtheleavestothebaseoftheplant. OutsidetheAndes,SouthAmericahastwoprincipalhighlandareas:theBrazilian HighlandsandtheGuianaHighlands.LocatedsouthoftheAmazonRiverin Brazil,theBrazilianHighlandsaremadeupoflowmountainsandplateausthat risetoanaverageelevationof1,006meters(3,300feet).TheGuianaHighlands arelocatedbetweentheAmazonandOrinocoRivers.Theheavilyforested plateauoftheGuianaHighlandscoverssouthernVenezuela,FrenchGuiana, Guyana,northernBrazil,andaportionofsoutheasternColombia. RiverBasins 2of9 SouthAmericahasthreeimportantriverbasins:theAmazon,Orinoco,and Paraguay/Paraná. TheAmazonRiverbasinhasanareaofalmost7millionsquarekilometers(2.7 millionsquaremiles),makingitthelargestwatershedintheworld.Thebasin, whichcoversmostofnorthernSouthAmerica,isfedbytributariesfromthe glaciersoftheAndes.Everysecond,theAmazonRiverempties209,000cubic meters(7,381,000cubicfeet)offreshwaterintotheAtlanticOcean. TheAmazonRiveristhelifeforceoftheequallyvastAmazonrainforest,which makesupabouthalfoftherainforestoftheentireplanet.Thistropicalbiome hasasmanyas100differenttreespeciesonasingleacre,includingtherubber tree,silkcottontree,andBrazilnuttree.Otherimportantplantspeciesinclude palms,ferns,andropelikevinesknownaslianasthatnetworkthroughoutthe rainforest’sdensecanopy. ThediversityofanimallifeintheAmazonrainforestisunsurpassedintherest oftheworld.Therainforestisperfectlysuitedforarboreal,ortree-living, animals.Morethan2millionspeciesofinsectsarenativetotheregion, includinghundredsofspidersandbutterflies.Primatesareabundant—howler monkeys,spidermonkeys,andcapuchinmonkeys—alongwithsloths,snakes, andiguanas.Thousandsofnativebirdsincludebrightlycoloredmacaws, parrots,toucans,andparakeets. TheOrinocoRiverflowsnorthoftheAmazon.TheOrinocoflowsinagiantarc formorethan2,736kilometers(1,700miles),originatingintheGuiana HighlandsofnorthernBrazilanddischargingintheAtlanticOceaninVenezuela. TheOrinocoRiverbasincoversanareaofabout948,000squarekilometers (366,000squaremiles)andencompassesapproximately80percentof Venezuelaand25percentofColombia. Avastsavannaorgrasslandregion,knownastheLlanos,istheprimarybiome 3of9 oftheOrinocoRiverbasin.TheLlanosisprimarilymadeupofgrasses.Swamp grasses,sedges,andbunchgrassarefoundinwet,low-lyingareas.Carpetgrass isfoundinthehigheranddrierelevations. Likemostgrasslandbiomes,theLlanosistheperfecthabitatformanybird species,includingthescarletibis,bellbird,andumbrellabird.Importantriver speciesincludethepiranha,electriceel,andtheOrinococrocodile,whichcan reachalengthofmorethan6meters(20feet). TheParaguay/ParanáRiverbasincoversalmost2.8millionsquarekilometers (1,081,000squaremiles),whichismuchofsoutheasternBrazilandBolivia, Paraguay,andnorthernArgentina.TheParanáRiverincludesIguazuFalls,a massiveseriesofwaterfallsthatextendfor2.7kilometers(1.7miles). AlongwiththeUruguayRiver,theParanáRiveremptiesintotheRiodelaPlata estuarybetweenArgentinaandUruguay.TheRiodelaPlataisthemost populatedregionofbothcountries.ThecapitalcitiesofBuenosAires,Argentina, andMontevideo,Uruguay,practicallyfaceeachotheracrosstheestuary. TheParaguay/ParanáRiverbasinsupplieswatertotheplainsbiome,orPampas, ofSouthAmerica.ThePampashaverich,fertilesoilandpredictablerainfall patterns.Theyarethemostimportantgrazingandcroplandareasonthe continent. CoastalPlains Acoastalplainisanareaoflow,flatlandnexttoaseacoast.SouthAmerican coastalplainsarefoundonthenortheasterncoastofBrazil,ontheAtlantic Ocean,andthewestern,PacificcoastofPeruandChile.Thecoastalplainsof northeasternBrazilareextremelydry.TheBrazilianHighlandsactasawedge thatpushesmoistseawindsawayfromthecoastalplains. Thewesterncoastalplainsarealsoextremelydry.Theyaretrappedbetween 4of9 thecoldPeruCurrenttothewestandtheAndesMountainstotheeast.The PeruCurrentbringscoldwatertothePacificcoastofPeruandChile.Thiscold surfacewaterresultsinthermalinversion:coldairatsealevelandstable, warmerairhigherup.Thermalinversionproducesathicklayerofcloudsatlow altitudes.Theselow-lyingcloudsblanketmuchofthePacificcoastofSouth America.Theydonotallowprecipitationtoform. TheAtacamaDesertispartofthewesterncoastalplain.TheAtacamais consideredthedriestregionintheworld.Theaveragerainfallisabout1 millimeter(0.04inches)ayear,andsomepartsoftheAtacamahaveneverhad raininrecordedhistory. Veryfewplantsgrowinthisdesert.Evenbacteria,insects,andfungiarescarce. Largeranimalspeciesarealsorare,andincludethegreyfox,atypeofdeer calledthehuemul,andtheviscacha—thelargestmemberofthechinchilla family.Oceanbirds,suchaspenguins,cormorants,andpelicans,arefoundon thedesertcoast.WhileAtacamalacksfloraandfauna,itisarichsourceof copperandachiefsourceofrevenuefortheChileaneconomy. Vocabulary Term Partof Definition Speech alpine adjectivehavingtodowithmountains. Altiplano noun arboreal adjectivehavingtodowithtrees. arc noun archipelago noun bacteria basin highplateauintheAndesMountainsofSouthAmerica. partoftheoutlineofacircle. agroupofcloselyscatteredislandsinalargebodyof water. plural (singular:bacterium)single-celledorganismsfoundin noun everyecosystemonEarth. noun adipordepressioninthesurfaceofthelandorocean floor. 5of9 Term Partof Definition Speech biodiversity noun allthedifferentkindsoflivingorganismswithinagiven area. areaoftheplanetwhichcanbeclassifiedaccordingtothe biome noun border noun canopy noun capital noun citywherearegion'sgovernmentislocated. chinchilla noun rodentnativetoSouthAmerica. climate noun cloud noun plantandanimallifeinit. naturalorartificiallineseparatingtwopiecesofland. oneofthetoplayersofaforest,formedbythethick leavesofverytalltrees. allweatherconditionsforagivenlocationoveraperiodof time. visiblemassoftinywaterdropletsoricecrystalsinEarth's atmosphere. coastalplainnoun low,flatlandlyingnexttotheocean. continent noun oneofthesevenmainlandmassesonEarth. copper noun chemicalelementwiththesymbolCu. crop noun agriculturalproduce. current noun dense havingpartsormoleculesthatarepackedclosely adjective together. desert noun drought noun economy noun endangered species noun environment noun steady,predictableflowoffluidwithinalargerbodyofthat fluid. areaoflandthatreceivesnomorethan25centimeters (10inches)ofprecipitationayear. periodofgreatlyreducedprecipitation. systemofproduction,distribution,andconsumptionof goodsandservices. organismthreatenedwithextinction. conditionsthatsurroundandinfluenceanorganismor community. 6of9 Term estuary Partof Definition Speech noun mouthofariverwheretheriver'scurrentmeetsthesea's tide. fauna noun fertile adjectiveabletoproducecropsorsustainagriculture. flora noun freshwater noun frost fungi noun plural noun animalsassociatedwithanareaortimeperiod. plantsassociatedwithanareaortimeperiod. waterthatisnotsalty. thincoatoficecoveringobjectswhenthedewpointis belowfreezing. (singular:fungus)organismsthatsurvivebydecomposing andabsorbingnutrientsinorganicmaterialsuchassoilor deadorganisms. glacier noun massoficethatmovesslowlyoverland. grassland noun ecosystemwithlarge,flatareasofgrasses. gulf noun portionofanoceanorseathatpenetratesland. herb noun huemul noun human geography noun mountain noun Pampas noun Patagonia noun physical typeofseasonalplantoftenusedasamedicineor seasoning. deernativetoSouthAmerica.AlsocalledtheSouth Andeandeer. thestudyofthewayhumancommunitiesandsystems interactwiththeirenvironment. landmassthatformsastectonicplatesinteractwitheach other. flatgrasslandsofSouthAmerica. largeplateauinsouthernSouthAmerica,stretchingfrom theAndesMountainstotheAtlanticOcean. noun studyofthenaturalfeaturesandprocessesoftheEarth. plain noun flat,smoothareaatalowelevation. plateau noun geography largeregionthatishigherthanthesurroundingareaand relativelyflat. 7of9 Term Partof Definition Speech precipitationnoun allformsinwhichwaterfallstoEarthfromthe atmosphere. primate noun rainforest noun region noun resource noun revenue noun rugged adjectivehavinganirregularorjaggedsurface. savanna noun typeoftropicalgrasslandwithscatteredtrees. sedge noun grass-likeplantnativetowetlands. soil noun toplayeroftheEarth'ssurfacewhereplantscangrow. stem noun mainstalkofaplant. surpass verb togobeyondasetlimit. swamp noun thermal inversion tributary noun noun typeofmammal,includinghumans,apes,andmonkeys. areaoftall,mostlyevergreentreesandahighamountof rainfall. anyareaonEarthwithoneormorecommon characteristics.Regionsarethebasicunitsofgeography. availablesupplyofmaterials,goods,orservices. Resourcescanbenaturalorhuman. income,ormoneyearnedbeforeproductioncostsare subtracted. landpermanentlysaturatedwithwaterandsometimes coveredwithit. climatepatternwheretheairiswarmerathigher elevations. streamthatfeeds,orflows,intoalargerstream. existinginthetropics,thelatitudesbetweentheTropicof tropical adjectiveCancerinthenorthandtheTropicofCapricorninthe south. unique adjectiveoneofakind. waterfall noun watershed noun flowofwaterdescendingsteeplyoveracliff.Alsocalleda cascade. entireriversystemoranareadrainedbyariverandits tributaries. 8of9 Term wedge Partof Definition Speech noun triangleshape. Articles&Profiles NationalGeographicNews:NewGlowingFungiSpeciesFoundinBrazil Images NationalGeographicPhotoGallery:ChileVolcanoEruptsWithAshand Lightning Maps NGMapMakerInteractive:LandCover—NorthandSouthAmerica NGMapMakerInteractive:SouthAmerica—AmazonRiver NationalGeographicEvents:GiantTravelingMapofSouthAmerica WeatherUnderground:SouthAmerica Websites NationalGeographicProjects:PatagoniaMeteoriteImpactFieldProject NationalGeographicTravel:SouthAmerica ©1996–2017NationalGeographicSociety.Allrightsreserved. 9of9