Where Did the Earth.docx
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Where Did the Earth.docx
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WhereDidtheEarth
WhereDidtheEarth'sWaterComeFrom?
WhydoesEarthhavesomuchwaterrelativetotheotherinnerplanets?
71%ofthesurfaceiscoveredintheoceans,morethanhalfofwhichisdeeperthan3,000meters(9,800ft),withanapproximatetotalvolumeof1.3billioncukm(310millioncumi).Still,theoceansonlymakeup0.023%oftheEarth'stotalmass.
TherearevarioustheoriesastowherealltheEarth'swatercamefrom,butseveraltheorieshavefaredbetterthantheothers.Weknowthattheoceansexistedasearlyas100millionyearsaftertheformationoftheEarth.WhentheEarthwasintheprocessofforming,witharadiusjust40%smallerthanatpresent,itwouldhavehadenoughgravitytoholdontoatenuousatmospherewithwatervapor.Thefirstwatervaporontheplanetwouldhavecomefromtheplanet'sinternals,wherevolatile(lowweight)chemicalswouldhaveatendencytofloattothetop,andheavychemicals(ironandnickel)wouldsink.
ThoughthefirstofEarth'swatercameaboutthroughvolcanism,thisaloneprobablydidn'tproduceenoughtoformstablepoolsonthesurface.Morewaterwasaddedtotheplanetduringseveralhypothesizedlargeimpactsfromasteroidsfromtheouterasteroidbelt.ComparingtheisotoperatiosofwateronEarthandwaterfromcometsandasteroidshasrevealedthatthemajorityoftheEarth'swatercomesfromasteroids
WaterFactsandTrivia
Factsandtriviaondifferentsubjectsconcerningwater
Didyouknow...?
Aboutwaterchemistryandwatermovement:
1.Mostoftheearth'ssurfaceconsistsofwater;thereismuchmorewaterthanthereisland.
2.Watercannotonlybefoundonthesurface,butalsointhegroundandintheair.
3.Thereisthesameamountofwateronearthastherewaswhentheearthwasformed.ThewaterthatcamefromyourfaucetcouldcontainmoleculesthatNeanderthalsdrank…
4.Theoverallamountofwateronourplanethasremainedthesamefortwobillionyears.
5.Therearetwokindsofwater;saltwaterandfreshwater.Saltwatercontainsgreatamountsofsalt,whereasfreshwaterhasadissolvedsaltconcentrationoflessthan1%.Onlyfreshwatercanbeappliedasdrinkingwater.
6.Waterconsistsofthreeatoms,2HydrogenatomsandanOxygenatom,thatarebondtogetherduetoelectricalcharges.
7.Theweightofawatermoleculedependsonthenumberofmolespresent,asitis18gramspermole.
8.Watermovesaroundtheearthinawatercycle.Thewatercyclehasfiveparts:
evaporation(蒸发),condensation(凝结),precipitation(沉淀),infiltration(渗透)andsurfacerun-off(地表径流).
9.Ina100-yearperiod,awatermoleculespends98yearsintheocean,20monthsasice,about2weeksinlakesandrivers,andlessthanaweekintheatmosphere.
10.Groundwatercantakeahumanlifetimejusttotraverseamile.
11.Mostoftheearth'ssurfacewaterispermanentlyfrozenorsalty.
12.Waterregulatestheearth'stemperature.
13.WaterfreezesatzerodegreesCelcius.
14.WatervaporizesatahundreddegreesCelcius.
15.Wateristheonlysubstancethatisfoundnaturallyonearthinthreeforms:
liquid,gas,solid.
16.Ifwaterchangesphaseitsphysicalappearancechangesduetopartingofwatermolecules.Inthesolidphasethewatermoleculesareclosetogetherandinthegaseousphasetheyarethefurthestapart.
17.Frozenwateris9%lighterthanwater,whichiswhyicefloatsonwater.
18.Alitreofwaterweighs1.01kilograms.
19.Itdoesn'ttakemuchsalttomakewater"salty."Ifone-thousandth(ormore)oftheweightofwaterisfromsalt,thenthewateris"saline."
20.Salinewatercanbedesalinatedforuseasdrinkingwaterbygoingthroughaprocesstoremovethesaltfromthewater.
21.Whenwatercontainsalotofcalciumandmagnesium,itiscalledhardwater.Hardwaterisnotsuitedforallpurposeswaterisnormallyusedfor.
22.Todeterminewaterqualitycertifiedagenciestakesamplesthataretestedinalaboratory.Thesamplesaretestedonvariousfactors,todetermineiftheysufficewaterqualitystandards.
23.Eachcountryhasitsownwaterqualitystandardsthatdeterminetowhichdegreewatershouldbepurified,dependingonthepurposeitwillbeusedfor.
Aboutwaterquantities:
1.Asoceansareverywideandtherearemultipletobefoundonearth,oceansstoremostoftheearth'swater.Thisisapparently97%ofthetotalamountofwateronearth,2%ofwhichisfrozen.
2.80%oftheearth'swaterissurfacewater.Theother20%iseithergroundwateroratmosphericwatervapour.
3.Ofallthewateronearth,only2,5%isfreshwater.Freshwateriseithergroundwater(0,5%),orreadilyaccessiblewaterinlakes,streams,rivers,etc.(0,01%).
4.Ifalltheworld'swaterwerefitintoagallonjug,thefreshwateravailableforustousewouldequalonlyaboutonetablespoon.
5.Over90%oftheworld'ssupplyoffreshwaterislocatedinAntarctica.
6.Lessthan1%ofthewatersupplyonearthcanbeusedasdrinkingwater.
7.Theearth'stotalamountofwaterhasavolumeofabout344millioncubicmiles.
·315millioncubicmilesisseawater.
·9millioncubicmilesisgroundwaterinaquifers.
·7millioncubicmilesisfrozeninpolaricecaps.
·53,000cubicmilesofwaterpassthroughtheplanet'slakesandstreams.
·4,000cubicmilesofwaterisatmosphericmoisture.
·3,400cubicmilesofwaterarelockedwithinthebodiesoflivingthings.
8.Approximately66%ofthehumanbodyconsistsofwater.Waterexistswithinallourorgansanditistransportedthroughoutourbodytoassistphysicalfunctions.
9.Thetotalamountofwaterinthebodyofanaverageadultis37litres.
10.Humanbrainsare75%water.
11.Humanbonesare25%water.
12.Humanbloodis83%water.
13.75%ofachickeniswater.
14.80%ofapineappleiswater.
15.95%ofatomatoiswater.
16.70%ofanelephantiswater.
17.Eachdaythesunevaporatesatrilliontonsofwater.
18.Asingletreewillgiveoff265liters(70gallons)ofwaterperdayinevaporation.
19.Anacreofcornwillgiveoff15,000litres(4,000gallons)ofwaterperdayinevaporation.
20.Asmalldripfromafaucetcanwasteasmuchas75litresofwateraday.
21.Theamountofwaterwedeliveronahotsummerday,308millionlitres(80milliongallons),couldfill1.28billioncupsofcoffee.
Aboutwater&health:
1.Apersoncanliveaboutamonthwithoutfood,butonlyaboutaweekwithoutwater.Ifahumandoesnotabsorbenoughwaterdehydrationistheresult.
2.Apersonmustconsume2litresofwaterdailytolivehealthily.Humansdrinkanaverageof75.000litresofwaterthroughouttheirlife.
3.Humanscannotdrinksaltwater.
4.Morethan2billionpeopleonearthdonothaveasafesupplyofwater.
5.Waterregulatesthetemperatureofthehumanbody.Ifyouhavecaughtafeveryoushoulddrinklotsofwater.
6.Waterremoveswastefromthehumanbody.
7.Youshouldneverdrinkwaterstraightfromalakeorriver,asitcanbedamagingtoyourhealth.
8.Ifyouliveinanoldhousewithleadpipelinesyoucouldgethealthproblems.Duetoweatheringofthepipelinesleadcanendupinyourtapwater.
9.Yourdrinkingwatermaybefluoridatedtohelppreventdentalcavities.
10.Waterleavesthestomachfiveminutesafterconsumption.
11.CentresforDiseaseControlreceivenotificationofmorethan4,000casesperyearofillnessduetodrinkingwatercontamination.
12.Aquarteroftheworld'spopulationiswithoutsafedrinkingwater.
13.Watercancauseserioushealthdamagewhenitiscontaminatedbybacteriaandothermicrorganisms.
14.Inmostcitiesandtowns,drinkingwaterfromthetapistreatedsothatpeopledon'tgetsickwithdiseasessuchascholeraandtyphoid,whicharecausedbybacteria,virusesorparasitesfoundnaturallyinthewater.
Aboutwateruseandsavingwater:
1.Humansusemoreandmorewatereachyear.
2.AmericansusefivetimestheamountofwaterthatEuropeansuse.
3.Humansdailyuseabout190litres(50gallons)ofwater.
4.Apersonpaysabout25centsforwateruseonadailybasis.
5.Twothirdsofthewaterusedinahomeisusedinthebathroom.
6.Toflushatoiletweuse7.5to26.5litres(2to7gallons)ofwater.
7.Inafive-minuteshowerweuse95to190litres(25to50gallons)ofwater.
8.Tobrushyourteethyouuse7.5litres(2gallons)ofwater.
9.Foranautomaticdishwasher35to45litres(9to12gallons)ofwaterisused.
10.Savingabottleofcoldwaterinthefridgeisbetterthattakingitfromthetap,becauseitsavestimeandwater.
11.Whilebrushingyourteeth,insteadofleavingthetaprunning,youshouldfillupaglasstorinseyourmouth.
12.Bathsuselesswaterthanatypicalshower.Soakinginapartiallyfilledtubwilluselesswaterthanashortshower.
13.Theaveragepersonspendslessthan1%ofhisorhertotalpersonalexpendituredollarsforwater,wastewater,andwaterdisposalservices.
14.Lessthan1%ofthewatertreatedbypublicwatersystemsisusedfordrinkingandcooking.
15.Bottledwatercanbeupto1000timesmoreexpensivethantapwateranditmaynotbeassafe.
16.Today,atleast400millionpeopleliveinregionswithseverewatershortages.
Aboutwaterpollutionandrelatedproblems:
1.Humanslargelyinfluencethefactorsthatdeterminewaterquality,astheydeposeofftheirwasteinwaterandaddallkindsofsubstancesandcontaminantsthatarenotnaturallypresent.Wenowknowmorethan70.000waterpollutants.
2.About450cubickilometresofwastewaterarecarriedintocoastalareasbyriversandstreamseveryyear.Thesepollutionloadsrequireanaddit
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