E-WASHINGTON - Ngexesha lokutshabalala okukhulu kwehlabathi, uMhlaba wawubonakala usondele kakhulu kwinkcazo yesihogo - esivuthayo, esiqhumayo kunye nesiqhushumbisi - esidalwe kugqabhuko-dubulo olukhulu lwentaba-mlilo, ngokutsho kophando olwenziwe eTshayina.
Ngokwemigaqo ye-geologic, yayikhawuleza ngokumangalisayo, kwaye inokubonelela ngesifundo esoyikisayo malunga nokutshintsha kwemozulu kwikamva lethu, ababhali bophononongo olutsha bathi. Yayisisiganeko sesithathu kwezintlanu kwimbali yehlabathi, okwenzeka kwanangaphambi kokuba iidinosaur zizulazule.
Oku kutshabalala kwabulala ngaphezu kweekota ezintathu zobomi kwesi sijikelezi-langa kwisiganeko izazinzulu ezisibize ngokuba kuKufa Okukhulu. Iindawo zokumba zaseTshayina zibonelela ngemihla emitsha kunye neenkcukacha zesiganeko, esenzeka ekupheleni kwePermian Era. Yenzekile kwiminyaka eyi-252 yezigidi eyadlulayo kwaye inokuba ithathe iminyaka engaphantsi kwe-100,000, imfutshane kakhulu kunokuba izazinzulu bezicinga, ngokutsho kophononongo olupapashwe ngoLwesine kwijenali yeSayensi.
Uphononongo lukwaxhasa ingcamango yenzululwazi ekhoyo yokuba isigebenga sokufa kubangelwe lutshintsho olukhulu lwemozulu - ukufudumala kwehlabathi, isitayile sangaphambili - okubangelwe yintshukumo yentaba-mlilo engaphaya kwamanqanaba ale mihla. Uphando lwenza imeko yokuba ukugqabhuka kwekharbon diokside kunye ne-methane ephoswe kwi-atmosfera eye yabangela ukufa kuthathe kuphela iminyaka engama-20,000, ngaphantsi kunokuba bekucingelwa ngaphambili, nangona ukonakala kwendalo kuthathe ixesha elide.
Kwaye kwaqhambuka imililo etshabalalisayo ehlabathini lonke, hayi nje apho kwaqhushumba khona iintaba-mlilo, latsho eli phepha.
Khawufane ucinge ukomisa iAmazon kwaye uyitshise, utshilo umbhali-mbhali uDouglas Erwin, umgcini we-paleobiology kwi-Smithsonian Institution. Ngokuqinisekileyo yayilixesha elibi kakhulu. Ubulala i-75 ukuya kwi-90 ipesenti yayo yonke into esemhlabeni. Ayizukuba mnandi kakhulu.
Umoya ngamanye amaxesha unokufana nomsi oshinyeneyo ngaphandle kwendawo yamandla yakudala yaseMpuma Yurophu, utshilo uErwin.
Yayikuphela kokuphela kwenyambalala embalini ukubulala izinambuzane ezomeleleyo, utshilo uErwin. Emva koko, zazimbalwa kakhulu iintlobo zezinto eziphilayo ezasalayo emhlabeni wonke, yaye zazinokwahluka okuncinane phakathi kwemimandla eyahlukahlukeneyo. Kwakusemva kwexesha apho iidinosaur kunye nezilwanyana ezanyisayo zazulazula emhlabeni.
Uphononongo lusekwe ngaphezulu kweshumi elinesibini lamacandelo anqamlezayo omhlaba, kokubini emhlabeni naphantsi kwamanzi, ngaphezulu kwamawaka eemayile kumazantsi eTshayina. Kodwa kufuneka bamele ihlabathi liphela, ngokunikezelwa kokutshintsha kwamazwekazi kwiminyaka eyi-250 yezigidi ezidlulileyo, utshilo umbhali okhokelayo uShu-zhong Shen weNanjing Institute of Geology and Paleontology. Uphononongo lukwanike ubungqina bokuqala bokuba ukufa elwandle nasemhlabeni kwenzeka ngaxeshanye.
U-Erwin uthe imozulu yatshintsha ngenxa yokufakwa ngokukhawuleza kwekharbon diokside kunye nemethane emoyeni. Olu phononongo aluqinisekisi ukuba lufudume kangakanani na, kodwa olunye uphando luthe amaqondo obushushu anyuke ukuya kuthi ga kwi-9 degrees Fahrenheit, nto leyo eyenza ukuba imozulu ibe shushu ngama-15 degrees kunanamhlanje.
Ezo gesi zegreenhouse ezibamba ubushushu mhlawumbi zakhululwa ngenxa yentaba-mlilo enkulu kakhulu eSiberia, utshilo. Ugqabhuko-dubulo-mhlawumbi amakhulu alo ahlala amawaka eminyaka - akhuphe i-carbon kunye ne-magma eninzi kunokuba uMhlaba ubonile amashumi ezigidi zeminyaka. Ugqabhuko-dubulo nje olunye luya kugubungela indawo elingana neVermont, utshilo u-Erwin.
Iingcali zangaphandle ziye zasabela ngeendlela ezahlukeneyo kolu phando.
URichard Twitchett weYunivesithi yasePlymouth eGreat Britain wayibiza ngokuba ngumzekeliso ogqwesileyo wokuba sifikelele kangakanani ekufikeleleni esona siganeko sikhulu sokuphela kwembali kwimbali yobomi emhlabeni.
Kodwa uLuanne Becker, owayesakuba yi-geochemist kwiYunivesithi yaseCalifornia Santa Barbara, akavumelani nesigqibo sikaShen malunga nokuba yintoni ebangele ukubhubha kwehlabathi. U-Becker ungumxhasi wexesha elide wembono encinci yokuba i-asteroid okanye i-comet ebetha uMhlaba ibangele oku kutshabalala.
Uye wathi ngelixa uphononongo lwenze umsebenzi omkhulu wokuchaza ukuba kwenzeke ntoni kwaye kuthatha ixesha elingakanani, andicingi ukuba intaba-mlilo iyodwa inokuvusa ezona ziganeko ziyintlekele yokuphela kwimbali yobomi emhlabeni. Endaweni yoko kuyakuthatha iintlekele ezininzi ukuba zenzeke ngaxeshanye (impembelelo kunye nentaba-mlilo) ukuqalisa isiganeko sokuphela kwenyambalala, wabhala kwi-imeyile.
Kodwa u-Erwin uthe ngaphandle kophando lwehlabathi, izazinzulu azikhange zifumane zimpawu ze-comet okanye impembelelo ye-asteroid ngexesha elifanelekileyo lokuphela.
U-Shen wafundisa ukuba uxinzelelo lwendalo belwakha kwaye emva koko lwabetha inqaku kwaye lwawa ngendlela ekhawulezayo.
Esi sisifundo kumaxesha angoku, utshilo uShen. Asazi ukuba kuya kwenzeka ntoni okanye kuya kwenzeka nini.
Olu tshintsho lwemozulu lwenzekile ngokwendalo, kwaye lwabulala yonke into, utshilo u-Erwin. Kodwa wathi ukuba abagxeki besayensi yokufudumala kwehlabathi bacinga ukuba kubonisa ukuba ukutshintsha kwemozulu akukho nto yakuzikhathaza ngayo kuba yenzekile ngokwendalo kwixesha elidlulileyo, eso sisigqibo esingalunganga.
Ndicinga ukuba isifundo osithathayo koku kukuba awufuni kusondela naphi na ekutshabalaleni okukhulu, utshilo u-Erwin. Kwathatha izigidi ezi-5 zeminyaka ngaphambi kokuba ubomi bubengcono kwakhona.
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Kwi-intanethi:
Inzululwazi: http://www.sciencemag.org
