Domains of envronment

Atmosphere, Lithosphere, Biosphere, Hydrosphere

1. UNIT-3
ECOLOGY
By: Aishwarya
Assistant Professor
CSE Department
MITS Gwalior

2. DOMAINS OF ENVIRONMENT
Lithosphere:Thesolidportionoftheearth
Atmosphere:Thegaseouslayersthatsurroundtheearth
Hydrosphere:Watercoversaverybigareaoftheearth’ssurfaceandthisareais
calledtheHydrosphere
Biosphere:Itisthenarrowzonewhereland,waterandairtogetherarefound.

3. DOMAINS OF ENVIRONMENT

4. LITHOSPHERE
ThetermwascoinedbyJOSEPHBARRELL(1914).
Thelithosphereisadomainconcerningland.Whenlandismeasured,itis
measuredbytakingsealevelasit’sbase.
TheheightofthelandisalsomeasuredbydenotingitaseitherASL(AboveSea
Level)orBSL(BelowSeaLevel).
TheEarthisdividedinto7continents.Asia,Europe,Africa,NorthAmerica,South
America,Antarctica,andAustralia.Continentsarethemostimportantdomainas
theyinhibitthelargestnumberoflifeforms.
AsiaisthelargestcontinentonEarthcoveringalmost1/3rdoftheEarth’sland.
AsiaandEuropetogetherform‘Eurasia‘.ItisfollowedbythecontinentofAfrica.
Africaisuniqueinitsownwaybecauseitistheonlycontinentthroughwhichthe
Equator,theTropicofCancer,andtheTropicofCapricornpassthrough.

5. LITHOSPHERE
EuropeislocatedentirelyintheNorthernHemisphereaswellassomeofitliesin
theEasternHemisphere.ItisborderedbytheArcticOceantothenorth,theAtlantic
Oceantothewest,andtheMediterraneanSeatothesouth.
NorthAmericaandSouthAmerica togetherform‘Americas’.NorthAmericais
thethirdlargestcontinentonEarth.IsthmusofPanamaconnectsNorthAmericato
SouthAmerica.TheNorthernHemisphereisalsocalledtheLandHemisphere
becausethegreaterpartofEarth’slandmassliesintheNorthernHemisphere.
AustraliaalsoknownasOceaniaisanislandcontinentsurroundedbytheIndian
andPacificoceans.Itisknownforits,theGreatBarrierReef,avastinteriordesert
wildernesscalledtheOutback,anduniqueanimalspecieslikekangaroosandduck-
billedplatypuseswhicharefoundnowhereelse.

6. LITHOSPHERE
AntarcticaisthesouthernmostcontinentandsiteoftheSouthPole,itisavirtually
uninhabitedandisinthecompletelyice-coveredland.AustraliaandAntarctica
entirelylieinthesouthernhemisphere.

7. LITHOSPHERE
Itiscomposedofcrust&uppermantlewhichconstitutethehard&rigidouter
layeroftheearth.Itincludesrocksandsoilwhichisactualmediumofgrowthof
plantsandanimalsandmicroorganisms.Thelithosphereisthickerincontinents
thanoceansfloor.

8. LITHOSPHERE
Itconsistsofthreemain
layers:
Crust,
Mantle,
Core

9. LITHOSPHERE
Crust:thecrustistheoutermostlayeroftheplanet,thecooledandhardenedpartof
theEarththatrangesindepthfromapproximately5-70km(~3-44miles).
Twotypes:
OceanicCrust:ThebottomlayerofthisiscomposedofSilicon&Magnesiumsoits
calledasSIMA.
Itisthinnestlayer.Itsthicknessisonly5-10km.
Oceaniccrustismademostlyofrockswithacompositionofbasalt(adarkcolored
rock)
ContinentalCrust:
TheuppermostlayerofthisiscomposedofSilicon&AluminumsoitscalledSIAl,
whichhasadepthofabout32to40km.
Continentalcrustismostlymadeofrockswithcompositionofgranite(alight
coloredrocks).

10. LITHOSPHERE
Mantle:
ItisItisthesecondlayeroftheearthandextendsfrom30km-2900kmwithan
averagedensityof2.7g/cm3
Itcontains83%ofthetotalvolumeand68%ofthetotalmassoftheearth.
Itismadeupofsilicaterichironandmagnesiumandisdividedfromthecrustbya
discontinuitycalledasMOHOROVICICDISCONTINUITY.
Diamondsaretinypiecesofthemantlewecanactuallytouch.Mostformatdepths
above200kilometers(124miles).Butrare“super-deep”diamondsmayhaveformed
asfardownas700kilometers(435miles)belowthesurface.Thesecrystalsarethen
broughttothesurfaceinvolcanicrockknownaskimberlite.
Themantle’soutermostzoneisrelativelycoolandrigid

11. LITHOSPHERE
Core:
Itisthedeepestlayerofearth.Itextendsfromadistanceof2900km–6371kmwith
anaveragedensityof4.3-11g/cm3.Mantleandcoreboundaryiscalledas
WEICHART-GUTENBERGDiscontinuity.
Corevolumeis16%ofearth’stotalvolumeandcoremassis32%ofearth’stotal
mass.Itisfurtherdividedinto2sub-zonesbythediscontinuitycalledas
LEHMANN-BULLENDiscontinuity.
•OUTERCORE:(2890km-5150km)
•INNERCORE:(5150km-6371km):

12. LITHOSPHERE
Core:
Theinnercore:
Thissolidmetalballhasaradiusof1,220kilometers(758miles),oraboutthree-
quartersthatofthemoon.It’slocatedsome6,400to5,180kilometers(4,000to3,220
miles)beneathEarth’ssurface.Extremelydense,it’smademostlyofironandnickel.
Theinnercorespinsabitfasterthantherestoftheplanet.
Theoutercore:
Thispartofthecoreisalsomadefromironandnickel,justinliquidform.Itsits
some5,180to2,880kilometers(3,220to1,790miles)belowthesurface.Heated
largelybytheradioactivedecayoftheelementsuraniumandthorium,thisliquid
churnsinhuge,turbulentcurrents.

13. HYDROSPHERE
Thedomainofwaterisreferredtoashydrosphere.Itcomprisesvarioussourcesof
wateranddifferenttypesofwaterbodieslikerivers,lakes,seas,oceans,etc.Itis
essentialforalllivingorganisms.
WateristhemostabundantsubstanceatthesurfaceofEarth.About1.4billioncubic
km(326millioncubicmiles)ofwaterinliquidandfrozenformmakeuptheoceans,
lakes,streams,glaciers,andgroundwatersfoundthere.
Itisthisenormousvolumeofwater,initsvariousmanifestations,thatformsthe
discontinuouslayer,enclosingmuchoftheterrestrialsurface,knownasthe
hydrosphere.
Only2.5%ofEarthswaterisfreshwater.Andeveninthis2.5%;approximately69%
isintheformofsnowandice.

14. HYDROSPHERE

15. HYDROSPHERE-FRESH WATER
Freshwaters:
Itsabout97percentoftheearth’swaterarestoredintheearth’soceans.Allother
watersthatisfitforhumanconsumptionandagricultureiscalledfreshwater.
Thebasicsourceoffreshwaterisprecipitation,butnotallprecipitationendsupas
partofthefreshwatersupply.
Watermovingacrossthesurfaceiscalledrunoff.Runoffbeginsasrainaccumulates
inthinsheetsofwaterthatmoveacrossthesurfaceoftheland.
Thesesheetscollectintoasmallbodyofrunningwateriscalledstream.Astreamis
definedasanybodyofwaterthatismovingacrosstheland

16. HYDROSPHERE-FRESH WATER

17. HYDROSPHERE-GROUND WATER
Waterthatsoaksintothegroundmovesdowntoasaturatedzonewhereitiscalled
groundwater.
Groundwatermovesthroughsedimentsandrocksbeneaththesurface,
slowlymovingdownhill.
Anintermittentstreamisoneinwhichthesourceofgroundwaterisinlowsupply
andflowonlypartofthetime.Theamountofrainfallthatbecomesrunoffor
groundwaterdependsonthefollowingfactors:
1. The type of soil in the surface
2. how dry the soil is
3. the amount and type of vegetation
4. the slope of the land
5. if the rainfall is a long, gentle one or a cloudburst

18. HYDROSPHERE-SURFACE WATER
Thelandareadrainedbyastreamisknownasthestream’sdrainageWatersbasinor
watershed.
Alinecalleddivideseparatedtwoadjacentwatersheds.
Acontinentaldivideseparatedriversystemsthatdrainintooppositesidesofa
continent.
Asmallerbodyofstandingwateriscalledapond,andoneofmuchlargersizeis
calledalake.
Anaturalpondorlakecreatedbybuildingdamiscalledareservoir.

19. HYDROSPHERE-SURFACE WATER

20. HYDROSPHERE-SURFACE WATER
Itisusedfor:
Waterstorage-Areservoirforwaterstorageiskeptasfullaspossibletostorewater.
Floodcontrol-Areservoirforfloodcontrolrequireslowwaterlevelinordertocatch
runoff,preventingwatersfromfloodingtheland.
Generatingelectricity-Areservoirusedtogenerateelectricityrequirestherelease
ofwaterfromthereservoir.Thewaterofstreams,ponds,lakesandreservoirsare
sourcesoffreshwaterandiscollectivelycalledsurfacewater

21. HYDROSPHERE-OCEAN WATER
FiveMajorOceansinorderoftheirsizeare
PacificOcean:Itisalmostcircularinshape.Asia,Australia,NorthandSouth
Americassurroundit.
TheAtlanticOcean:Itisthesecond-largestoceanintheworld.Itis‘S’shaped.Itis
flankedbytheNorthandSouthAmericasonthewesternside,andEuropeandAfrica
ontheeasternside.
TheIndianOcean:Itistheonlyoceannamedafteracountry,thatis,India.The
shapeoftheoceanisalmosttriangular.Inthenorth,itisboundbyAsia,inthewest
byAfricaandintheeastbyAustralia.
TheSouthernOcean:ItsurroundsthecontinentofAntarctica
TheArcticOcean:ItislocatedwithintheArcticCircleandsurroundstheNorth
Pole.TheBeringstraitanarrowstretchofshallowwaterconnectsitwiththePacific
Ocean.

22. OceanFacts
•ThePacificOceanisthelargestofthefourmainoceans
•TheAtlanticOceanisthebusiestocean.ManyshipscrosstheAtlantic,carrying
cargobetweentheAmericas,Africa,andEurope
•TheArcticOceanisthesmallestandcoldestocean
•Theaveragetemperatureofalloceansisabout39degreesF(3.8degreesC)
•Oceansarealwaysmoving
•Tideschangetwiceadayallovertheworld,astheoceansriseandfallalongthe
shoreline.Scientiststhinkthisiscausedbythepullofthesunandmoononour
Earth,andtheEarth'srotation.
•Coralreefsarevast,rockyareaslocatedinshallow,tropicalwaters.Coralreefsare
likethetropicalrainforestoftheoceaninthatthegreatestvarietyofplantand
animallifeintheoceanlivethere.Coralreefsareformedfromthebodiesofsmall
seacreaturescalledpolyps
•Theworld'soceanscontainnearly20milliontonsofgold

23. ATMOSPHERE
Theearthissurroundedbyalayerofgascalledtheatmosphere.
Theatmosphereextendsuptoaheightofabout1,600kilometres.
Theatmosphereisdividedintofivelayersbasedoncomposition,temperatureand
otherpropertiesandtheyare:
•the troposphere
•the stratosphere
•the mesosphere
•the thermosphere
•the exosphere
About99percentofcleananddryairintheatmosphereiscomposedmainlyof
nitrogenandoxygen.Nitrogen78percent,oxygen21percentandothergases
likecarbondioxide,argonandotherscomprise1percentbyvolume.

24. ATMOSPHERE

25. ATMOSPHERE
Exosphere—containsfewparticlesthatmoveintoandfromspace.
Exobase—thelowerboundaryoftheexosphere.
Thermosphere—temperatureincreaseswithheight.Thetemperaturescanriseto
1,500degreesCelsius,butitwouldnotfeelwarmbecauseofthelowairpressure
inthislayer.
mesopause—theboundarybetweenthemesosphereandthethermosphere;the
coldestplaceonEarth.
mesosphere—thelayerinwhichmostmeteorsburnupafterenteringEarth’s
atmosphereandbeforereachingEarth’ssurface.
stratopause—theboundarybetweenthemesophereandthestratosphere.
stratosphere—containstheozonelayer;thelayerwherevolcanicgasescanaffect
theclimate.
tropopause—theboundarybetweenthestratosphereandtroposphere.
troposphere—thelayerclosesttoEarth’ssurfaceinwhichallweatheroccurs.

26. ATMOSPHERE COMPOSITION

27. ATMOSPHERE LAYERS IN DETAILS
TheTroposphere:Thisisthelowestpartoftheatmosphere-thepartwelivein.It
containsmostofourweather-clouds,rain,snow.Inthispartoftheatmosphere
thetemperaturegetscolderasthedistanceabovetheearthincreases,byabout
6.5°Cperkilometre.
Thetropospherecontainsabout75%ofalloftheairintheatmosphere,andalmost
allofthewatervapour(whichformscloudsandrain).
TheStratosphere:Thisextendsupwardsfromthetropopausetoabout50km.It
containsmuchoftheozoneintheatmosphere.
Theincreaseintemperaturewithheightoccursbecauseofabsorptionofultraviolet
(UV)radiationfromthesunbythisozone.Temperaturesinthestratosphereare
highestoverthesummerpole,andlowestoverthewinterpole

28. ATMOSPHERE LAYERS IN DETAILS
ByabsorbingdangerousUVradiation,theozoneinthestratosphereprotectsus
fromskincancerandotherhealthdamage.
Howeverchemicals(calledCFCsorfreons,andhalons)whichwereonceusedin
refrigerators,spraycansandfireextinguishershavereducedtheamountofozone
inthestratosphere,particularlyatpolarlatitudes,leadingtotheso-called
"Antarcticozonehole".
TheMesosphere:Theregionabovethestratosphereiscalledthemesosphere.
Herethetemperatureagaindecreaseswithheight,reachingaminimumofabout-
90°Catthe"mesopause".

29. ATMOSPHERE LAYERS IN DETAILS
TheThermosphereandIonosphere: Thethermosphereliesabovethe
mesopause,andisaregioninwhichtemperaturesagainincreasewithheight.This
temperatureincreaseiscausedbytheabsorptionofenergeticultravioletandX-
Rayradiationfromthesun.
Theregionoftheatmosphereaboveabout80kmisalsocausedthe"ionosphere",
sincetheenergeticsolarradiationknockselectronsoffmoleculesandatoms,
turningtheminto"ions"withapositivecharge.
Thetemperatureofthethermospherevariesbetweennightanddayandbetween
theseasons,asdothenumbersofionsandelectronswhicharepresent.
TheExosphere:Theregionaboveabout500kmiscalledtheexosphere.It
containsmainlyoxygenandhydrogenatoms,buttherearesofewofthemthat
theyrarelycollide-theyfollow"ballistic"trajectoriesundertheinfluenceof
gravity,andsomeofthemescaperightoutintospace.

30. BIOSPHERE
Thebiosphereisthenarrowzoneofcontactbetweentheland,waterandair.Itisthe
zonewherelifeexiststhatmakesthisplanetunique.Theorganismsinthebiosphere
arecommonlydividedinto:
•theplantkingdom
•theanimalkingdom
Thethreedomainsoftheearthinteractwitheachotherandaffecteachotherinsome
wayortheother.
•Everylivingthing,everyplant,everylake,andeverydesertisapartofit.It's
prettymassiveandprettyamazing.Thisisthelargestcategoryoforganizationfor
biologists.
•It'sdifferentfromthenextlevelofecologicalorganization,thebiome.The
biospherecanbedividedintoseveralbiomes.
•Theseregionshavespecificclimates,vegetation,animals,andadaptations
necessarytosurviveinthem

31. WHERE DID THE BIOSPHERE ORIGINATE?
•Thebiospherehasexistedforabout3.5billionyears.
•Thebiosphere’searliestlife-forms,calledprokaryotes,survivedwithoutoxygen.
Ancientprokaryotesincludedsingle-celledorganismssuchasbacteriaand
archaea.
•Someprokaryotesdevelopedauniquechemicalprocess.Theywereabletouse
sunlighttomakesimplesugarsandoxygenoutofwaterandcarbondioxide,a
processcalledphotosynthesis.
•Thesephotosyntheticorganismsweresoplentifulthattheychangedthebiosphere.
•Overalongperiodoftime,theatmospheredevelopedamixofoxygenandother
gasesthatcouldsustainnewformsoflife.

32. WHERE DID THE BIOSPHERE ORIGINATE?
•Theadditionofoxygentothebiosphereallowedmorecomplexlife-formsto
evolve.Millionsofdifferentplantsandotherphotosyntheticspeciesdeveloped.
•Animals,whichconsumeplants(andotheranimals)evolved.Bacteriaandother
organismsevolvedtodecompose,orbreakdown,deadanimalsandplants.
•Thebiospherebenefitsfromthisfoodweb.Theremainsofdeadplantsand
animalsreleasenutrientsintothesoilandocean.Thesenutrientsarere-absorbed
bygrowingplants.Thisexchangeoffoodandenergymakesthebiosphereaself-
supportingandself-regulatingsystem.

33. BIOSPHERE RESERVES
•Peopleplayanimportantpartinmaintainingtheflowofenergyinthebiosphere.
•Forexample,intheatmosphere,oxygenlevelsdecreaseandcarbondioxidelevels
increasewhenpeopleclearforestsorburnfossilfuelssuchascoalandoil.
•Oilspillsandindustrialwastesthreatenlifeinthehydrosphere.
•Thefutureofthebiospherewilldependonhowpeopleinteractwithotherliving
thingswithinthezoneoflife.
•Intheearly1970s,theUnitedNationsestablishedaprojectcalledManandthe
BiosphereProgramme(MAB),whichpromotessustainabledevelopment.
•Currently,thereare563biospherereservesallovertheworld.
•ThefirstbiospherereservewasestablishedinYangambi,DemocraticRepublicof
Congo.Yangambi,inthefertileCongoRiverBasin,has32,000speciesoftrees
andsuchendemicspeciesasforestelephantsandredriverhogs.

34. HOW DOES LIFE SUSTAIN ITSELF IN THE BIOSPHERE?
•Scientistsbelievethattheincreaseofatmosphericoxygenledtotheevolutionof
thefirstformsoflife.
•Energyisneededforthefunctionthatorganismsperform,suchasgrowth,
movement,wasteremovalandreproduction.Itistheonlyrequirementthatliving
organismsinthebiosphereneedapartfromwhatisthereinthefourmajor
domains.
•Thesourceofthisenergycomesfromthesun.Plantsconvertthesun’senergyinto
foodandareveryimportanttothebiosphere.

35. WHAT PROCESSES OCCUR IN THE BIOSPHERE?
Theorganismsinthebiosphereareconstantlyinvolvedinoneormoreofthe
followingprocesses:
•Decomposition:Thebreakdownofcomplexmolecules—moleculesofwhich
deadorganismsarecomposed–intosimplenutrientsthatcanbere-utilizedby
livingorganisms.
•Energy:Powerthatcanbeusedtoperformwork,suchassolarenergy.
•Nutrientcycle:Thecyclingofbiologicallyimportantelementsfromone
molecularformtoanotherandbacktotheoriginalform.
•Photosynthesis:Processinwhichplantscapturelightenergyfromthesunand
useittoconvertcarbondioxideandwaterintooxygenandorganicmolecules.
•Respiration:Chemicalreactionbetweenorganicmoleculesandoxygenthat
producescarbondioxide,water,andenergy.