Ekupheleni kwe ICenozoic Ngexesha leCretaceous kwabakho ukongezwa okukhulu okubandakanya zonke iidinosaurs kunye nobuninzi beentlobo eziphilayo. Eyona nkolelo yamkelekileyo yeyokuwa kokuwa kwe-meteorite enkulu kuMbindi Merika. Ukulandela isixa esikhulu sothuli emoyeni, bathintela ukukhanya kwelanga ukuba kungafikeleli ngaphezulu, kunika izityalo ezingakwaziyo ukwenza ifotosinthesize kunye nokuchaphazela kakubi ukutya. Kuxa iipesenti ezingama-35 zabo bonke ubomi eMhlabeni ziswelekile, zinika indlela Ixesha lomkhenkce.
Ngaba uyafuna ukwazi yonke into malunga nokwenzekileyo ngexesha lomkhenkce? Ngaba sisondela kwelinye ixesha lomkhenkce? Kule posi ungafunda yonke into.
Ukunyamalala kweentyatyambo kunye nezilwanyana
Ukunyamalala kwezirhubuluzi ezikhulu kwathatha indawo yokuba ngumkhenkce owaziwayo. Ngeli xesha, izilwanyana ezanyisayo zasebenzisa ithuba lokushiywa ziidinosaurs ukuze zande kwaye zisasaze. Ukongeza, ngenxa yeminqamlezo yemfuza, iintlobo ezintsha zazalwa kwaye ke izilwanyana ezanyisayo zahluka. Ekugqibeleni, ukwandiswa kwabo kwakubangela ukuba babeke ubukhosi babo kubo bonke abanye bezilwanyana ezinomqolo. Kwiintsapho ezili-10 ezazikho ekuqaleni kweli xesha lomkhenkce, baba phantse i-80 kwi-Eocene kwiminyaka nje eyi-10 yezigidi yendaleko.
Jonga kwi Ixesha lejoloji ukuba awuzibeki kakuhle kwinqanaba lesikali 🙂
Uninzi lweentsapho zamanina zanamhlanje zibuyela e-Oligocene, oko kukuthi, malunga nezigidi ezingama-35 zeminyaka edlulileyo. KwakuseMiocene (phakathi kweminyaka engama-24 ne-5 yezigidi eyadlulayo) xa ezona ntlobo zininzi zahlukeneyo zabhalwa ngexesha lomkhenkce.
Ngokuchasene nenkolelo edumileyo, Iminyaka yomkhenkce ayithethi ukuba umhlaba uphela ugutyungelwe ngumkhenkce, kodwa ezi zihlala kwipesenti ephezulu kunesiqhelo.
Kweli xesha lokugqibela kwavela iHominoidea yokuqala kunye neyokuqala, efana neProcessulul, iDryopithecus kunye neRamapithecus. Ukuqala kwiMiocene, inani lezilwanyana ezanyisayo laqala ukwehla kwaye, ngenxa yeenguqu ezinzulu zemozulu ezenzeka ngexesha lePliocene, malunga nezigidi ezi-2 zeminyaka eyadlulayo, uninzi lweentlobo zanyamalala.
Kulapho ke xa ixesha lomkhenkce lalizakuqala ngaphakathi kwePleistocene apho ookhwelwe babeqhubela phambili kwaye omnye wabo wayeza kunyanzelisa ulawulo lwakhe: Uhlobo lweHomo.
Iimpawu zexesha lomkhenkce
Ubudala bomkhenkce buchazwa njengexesha lexesha elibonakaliswa bubukho obungapheliyo bekhava yomkhenkce. Lo mkhenkce udlulela kwesinye sezibonda. Umhlaba uyaziwa ukuba uchithe iipesenti ezingama-90 zexesha lawo ngexesha kwiminyaka ezizigidi zokugqibela kwi-1% lamaqondo obushushu abanda kakhulu. La maqondo obushushu asezantsi ukusukela kwiminyaka eyi-500 yezigidi edlulileyo. Ngamanye amagama, uMhlaba ubanjwe kwindawo ebanda kakhulu. Eli xesha laziwa njengeQuaternary Ice Age.
Amaxesha okugqibela omane omkhenkce enzeka ngaminyaka engama-150 ezigidi. Ke ngoko, izazinzulu zicinga ukuba zibangelwa lutshintsho kumjikelezo woMhlaba okanye kutshintsho kwimisebenzi yelanga. Ezinye izazinzulu zikhetha inkcazo yomhlaba. Umzekelo, ukubonakala kwexesha lomkhenkce kubhekisele kusasazo lwamazwekazi okanye uxinzelelo lweegesi zegreenhouse.
Ngokwenkcazo ye-glaciation, lixesha elibonakaliswa bubukho bemikhenkce kwiipali. Ngalo mthetho-siseko wesithathu, ngoku sitshone kwisigaba seqhwa, kuba iminqwazi ye-polar ihlala phantse i-10% yomhlaba wonke.
I-Glaciation iqondwa njengethuba lamaxesha omkhenkce apho amaqondo obushushu asezantsi kakhulu kwihlabathi liphela. Imikhenkce, ngenxa yoko, iya kwinqanaba eliphantsi kwaye ilawula amazwekazi. Iminqwazi yomkhenkce ifunyenwe kububanzi beikhweyitha. Ixesha lokugqibela lomkhenkce lenzeka malunga ne-11 lamawaka eminyaka eyadlulayo.
Ngaba sikufuphi kwixesha elitsha lomkhenkce?
Kulo nyaka ubusika kumzantsi-ntshona weIberia buhlala ixesha elide kunesiqhelo. Intwasahlobo ibipholile ukufikelela kwiidigri ze-2 ngaphantsi komndilili we-20 iminyaka edlulileyo. Inyanga kaJuni nayo yayiqhaqhazelisa amazinyo amaqondo obushushu ayi-4 engaphantsi kunesiqhelo.
Utshintsho lwemozulu luhlala lusenzeka kwiplanethi kwaye hayi ngenxa yokuvela komntu kunye nohlaziyo lweshishini. Olu lolutshintsho oluye lwabangela ukuba izityalo nezilwanyana zomhlaba zitshintshe kwaye kukho amaxesha okomkhenkce kunye nokwahlukana.
Zininzi izinto ezingenelela kwimozulu yesijikelezi-langa. Ke ngoko, nangona izazinzulu zisitsho ukuba ukufudumala luxanduva olukhethekileyo lweegesi zegreenhouse (ikhonkco), akuxhomekekanga kulo kuphela. Ukugxininiswa kwabo kuyaqhubeka nokunyuka kule minyaka idlulileyo, kodwa amaqondo obushushu awanyukanga ngendlela ehambelana nayo. Kukho ihlobo elishushu nangona kungenjalo ngokulandelelana.
Konke oku kwenza ukuba uluntu lwenzululwazi lucinge ukuba, nangona sibangela ukufudumala kwe-anthropised global ngesantya esikhawulezayo kunendalo asizokwazi ukumisa ukuphela kwexesha eliphakathi kunye nokufika kwexesha elitsha lomkhenkce.
Kwenzeka ntoni kwixesha lokugqibela lomkhenkce?
Okwangoku sikwixesha lokuhlangana phakathi kwe-Quaternary glaciation. Indawo engaphezulu egcinwe yiminqwazi ye-polar ifikelela kwi-10% yomhlaba wonke. Ubungqina busixelela ukuba phakathi kwesi sithuba se-quaternary, kukho amaxesha amaninzi e-ice.
Xa abemi bebhekisa kwi "the ice age" ibhekisa kwixesha lokugqibela lomkhenkce eli xesha lokuzalwa. IQuaternary yaqala kwiminyaka engama-21000 eyadlulayo kwaye yaphela malunga neminyaka eli-11500 XNUMX eyadlulayo. Kwenzeke ngaxeshanye kuzo zombini iihemispheres. Elona likhulu likhulu lomkhenkce lafikelelwa kumantla eikhweyitha. EYurophu, umkhenkce waqhubela phambili, wagubungela iGreat Britain, iJamani nePoland. Yonke iNyakatho Melika yangcwatywa phantsi komkhenkce.
Emva kokubanda, Umgangatho wolwandle wehla ngeemitha ezili-120. Ububanzi obukhulu bolwandle namhlanje babenzelwe elo xesha emhlabeni. Namhlanje, kuqikelelwe ukuba xa umkhenkce oshiyekileyo unyibilikile, amanqanaba elwandle angenyuka phakathi kwe-60 kunye ne-70 yeemitha.
Ucinga ntoni ngokufika kwexesha elitsha lomkhenkce? Sazise kumagqabantshintshi.
Ndingumntu okwathi ngeminyaka yoo-1980 waqikelela kungekuphela nje ukuba i-Ice Age entsha yayisondele kodwa ukuba kunokwenzeka ukuba sasisele siphila kuloo minyaka singaqondanga. Imikhwa yamaqondo obushushu, umjikelo wendalo ekufuneka uhanjiswe nguMhlaba kunye nokufudumala kwesijikelezi-langa ngokwawo ibizezona mpawu zichaphazele umbono wam. Ngokumalunga neyona nto iphikisanayo yezalathi okanye ukufudumala kweplanethi, uphando olwenziwe e-Antarctica olugqibe kwelokuba ukufudumala kwehlabathi okanye iplanethi ihlala iphambi kwexesha lomkhenkce kufuneka ithathelwe ingqalelo.
Njengoko usitsho, i-Ice Age yinto engenakuphinda ibuye kwaye ingathinteleki:
“Konke oku kwenza ukuba izazinzulu zicinga ukuba, nangona sibangela ukufudumala komhlaba ngokukhawuleza kunokuba indalo isitsho, asizokwazi ukumisa ukuphela kwexesha eliphakathi kunye nokufika kwexesha elitsha umkhenkce. "
Injineli uLee carroll, kwizifundo zakhe zokuhambisa amandla eKryon, usimema ukuba silungiselele ixesha lomkhenkce eseliqale kulo nyaka we-2019.
Ubungqina, njengoko usitsho, kwiirekhodi zomoya obanjwe kwisilinda zomkhenkce eAntarctica, nakwimisesane yomthi. Isimema ukuba sikhulise amandla okuzanelisa ngokwasekhaya, ekuhlaleni, nakumanqanaba ezindlu. Ngenxa yokuba «igridi yombane ayilungelanga ukumelana nexesha lomkhenkce. Isenokungaphumeleli. Kwaye iyakusilela »