Ekupheleni kwe I-Cenozoic ngesikhathi seCretaceous kube nokwandiswa okukhulu okubandakanya wonke ama-dinosaurs nobuningi bezinhlobo eziphilayo. Umbono owamukelwa kakhulu owokuwa kwesibhakabhaka esikhulu endaweni eseMelika Ephakathi. Ukulandela uthuli olukhulu emoyeni, bavimbele ukukhanya kwelanga ukuthi kufinyelele ngaphezulu, okwenza izitshalo zingakwazi ukwenza i-photosynthesize futhi zithinte kakhulu uchungechunge lokudla. Kungaleso sikhathi lapho u-35% wayo yonke impilo eMhlabeni yafa, yavuma Isikhathi seqhwa.
Ngabe ufuna ukwazi yonke into ngokwenzeka esikhathini seqhwa? Ingabe sisondela kwenye inkathi yeqhwa? Kulokhu okuthunyelwe ungafunda konke.
Ukunyamalala kwezitshalo nezilwane
Ukunyamalala kwezilwane ezihuquzelayo ezinkulu kwavulela abaziwayo indawo i-ice Age. Ngalesi sikhathi, izilwane ezincelisayo zasebenzisa igebe elishiywe ama-dinosaurs ukuze zande futhi zisakazeke. Ngaphezu kwalokho, ngenxa yokuhlukahluka kwezakhi zofuzo, kwazalwa izinhlobo ezintsha futhi kanjalo izilwane ezincelisayo zahlukahluka. Ekugcineni, ukwanda kwazo kwaba kangangokuthi zabeka ukubusa kwazo kuzo zonke ezinye izilwane ezinomgogodla. Emindenini engu-10 eyayikhona ekuqaleni kwalenkathi yeqhwa, yaba cishe ama-80 e-Eocene eminyakeni eyizigidi eziyishumi nje yokuziphendukela kwemvelo. Ukuvela kwalezi zinhlobo kungabuye kufundwe emakhasini mayelana izikhathi ze-geological kanye nomthelela wayo esimweni sezulu samanje. Ngaphezu kwalokho, ungafunda okwengeziwe mayelana izinguzunga zeqhwa eziye zathinta iplanethi esikhathini esidlule.
Bheka i- isikhathi sokuma komhlaba uma ungazibeki kahle esikalini sesikhathi
Imindeni eminingi yesimanje esincelisayo isukela e-Oligocene, okungukuthi, cishe eminyakeni eyizigidi ezingama-35 edlule. Kwakungaleso sikhathi eMiocene (phakathi kweminyaka engama-24 no-5 yezigidi edlule) lapho izinhlobonhlobo ezinkulu kakhulu zezinto eziphilayo zaqoshwa ngesikhathi seqhwa.
Ngokuphikisana nenkolelo evamile, inkathi yeqhwa ayisho ukuthi yonke iplanethi imbozwe yiqhwa, kodwa lezi zithatha amaphesenti angaphezu kwavamile. Lokhu kubalulekile ukuqonda umongo wento engenzeka iminyaka encane yeqhwa, okungase kube nomthelela esimweni sezulu sembulunga yonke.
Kulesi sikhathi sokugcina kwavela iHominoidea yokuqala neyokuqala, njengeProcessulul, iDryopithecus neRamapithecus. Kusukela eMiocene, inani lezilwane ezincelisayo laqala ukwehla futhi, ngenxa yezinguquko ezinkulu zesimo sezulu ezenzeka ngesikhathi sePliocene, cishe eminyakeni eyizigidi ezimbili edlule, izinhlobo eziningi zanyamalala.
Kungaleso sikhathi lapho isikhathi seqhwa sase sizoqala ngaphakathi kwePleistocene lapho ama-primates ayeqhubekela phambili futhi omunye wabo wayezophoqa umbuso wakhe: uhlobo loHomo.
Izici zobudala beqhwa
Isikhathi seqhwa sichazwa njengesikhathi sesikhathi esibonakala ngokuba khona okungapheli kwesembozo seqhwa esikhulu. Leli qhwa lifinyelela okungenani ezigxotsheni esisodwa. Umhlaba waziwa ukuthi uchithe ama-90% wesikhathi sawo ngesikhathi iminyaka eyizigidi zokugcina ku-1% wamazinga okushisa abanda kakhulu. La mazinga okushisa aphansi kakhulu kusukela eminyakeni eyizigidi ezingama-500 edlule. Ngamanye amagama, uMhlaba ubhajwe esimweni esibandayo kakhulu. Lesi sikhathi saziwa njengeQuaternary Ice Age.
Izikhathi ezine zokugcina zeqhwa zenzeke ngezikhathi zeminyaka eyizigidi ezingu-150. Ngakho-ke, ososayensi bakholelwa ukuthi kungenxa yezinguquko ku-orbit yomhlaba noma izinguquko emisebenzini yelanga. Abanye ososayensi bakhetha incazelo yasemhlabeni. Isibonelo, zibhekisela ekubukeni kweqhwa, ukusatshalaliswa kwamazwekazi noma ukugcwala kwamagesi abamba ukushisa njengalawo okukhulunywe ngawo ku. ukulahlekelwa ukulawula ukushintsha kwesimo sezulu.
Ngokwencazelo ye-glaciation, kuyisikhathi esibonakala ngokuba khona kwama-ice caps ezigxotsheni. Ngaleso simiso sesithupha, njengamanje sesicwiliswe esikhathini seqhwa, ngoba amakepisi asezindaweni ezibandayo ahlala cishe amaphesenti ayi-10 womhlaba wonke.
I-Glaciation iqondakala njengenkathi yeminyaka yeqhwa lapho izinga lokushisa liphansi kakhulu emhlabeni jikelele. Amaqhwa eqhwa, ngenxa yalokho, adlulela ngasezindaweni eziphansi futhi abusa amazwekazi. Kutholakale izingqimba zeqhwa ebangeni le-equator. Isikhathi sokugcina seqhwa senzeka cishe eminyakeni eyizinkulungwane eziyi-11 eyedlule.
Ngabe sesiseduze nenkathi entsha yeqhwa?
Kulo nyaka ubusika eningizimu-ntshonalanga yeNhlonhlo Yase-Iberia buqhubeke isikhathi eside kunokujwayelekile. Intwasahlobo bekulokhu kupholile sifinyelela kuma-2 degrees ngaphansi kwesilinganiso seminyaka engama-20 edlule. Inyanga kaJuni nayo ibibanda ngokungajwayelekile ngamazinga okushisa angama-4 degrees angaphansi kokujwayelekile.
Izinguquko zesimo sezulu bezilokhu zenzeka kwiplanethi hhayi ngenxa yokubonakala komuntu kanye nenguquko yezimboni. Yilezi zinguquko ezidale ukuthi izitshalo nezilwane zomhlaba ziguquke futhi kube nezikhathi zeqhwa nezokuhlangana.
Kunezici eziningi ezithonya isimo sezulu seplanethi. Ngakho-ke, nakuba ososayensi beveza ukuthi ukufudumala kwembulunga yonke kuwumthwalo wemfanelo wamagesi abamba ukushisa, akubangelwa wona kuphela. Ukugxila kwabo kuyaqhubeka nokukhuphuka phakathi neminyaka, kodwa izinga lokushisa alizange lenyuke ngokulinganayo. Kukhona ihlobo elishisayo, nakuba lingalandelani.
Konke lokhu kwenza umphakathi wezesayensi ucabange ukuthi, yize sibanga ukufudumala kwembulunga yonke okungahlonziwe ngesivinini esisheshayo kunemvelo ngeke sikwazi ukumisa ukuphela kwenkathi yokuhlangana kanye nokufika kwenkathi entsha yeqhwa. Lokhu kuyinto ebuye kukhulunywe ngayo ezingxoxweni zokuthi inkathi yeqhwa elandelayo eSpain ngeke kugwemeke.
Kwenzekani esikhathini sokugcina seqhwa?
Njengamanje sisesikhathini esihlangene phakathi kwe-Quaternary glaciation. Indawo lapho kuhlala khona amakepisi asezindaweni ezibandayo ifinyelela ku-10% womhlaba wonke. Ubufakazi busitshela ukuthi phakathi nalesi sikhathi sekota, kube nezikhathi eziningi zeqhwa.
Lapho inani labantu libhekise ku- "Isikhathi seqhwa" Kusho isikhathi sokugcina seqhwa salesi sikhathi se-quaternary. IQuaternary yaqala eminyakeni engama-21000 edlule futhi yaphela cishe eminyakeni eyi-11500 XNUMX edlule. Kwenzeka ngasikhathi sinye kuwo womabili ama-hemispheres. Izandiso ezinkulu zeqhwa zafinyelelwa enyakatho yezwe. EYurophu, iqhwa laqhubekela phambili, lamboza lonke iGreat Britain, iGerman nePoland. Yonke iNyakatho Melika yangcwatshwa ngaphansi kweqhwa.
Ngemuva kokubanda, ulwandle lwehle ngamamitha ayi-120. Izikhala ezinkulu zolwandle namuhla zazenzelwe leyo nkathi emhlabeni. Namuhla, kubalwa ukuthi uma izinguzunga zeqhwa ezisele zingancibilika, ulwandle belungakhuphuka phakathi kwamamitha angama-60 kuya kwangama-70.
Ucabangani ngokufika kwenkathi entsha yeqhwa? Sazise emazwaneni.
Ngingumuntu okwathi ngeminyaka yama-1980 angalinganiseli nje kuphela ukuthi i-Ice Age entsha yayiseduze kodwa nokuthi kungenzeka ukuthi sasivele siphila leyo minyaka singanakile. Ukuthambekela kwamazinga okushisa, umjikelezo wemvelo okumele uMhlaba uwalandele ngisho nokushisa kweplanethi uqobo kwakuyizinkomba ezathonya kakhulu umbono wami. Mayelana nokuphikisana okukhulu kwezinkomba noma ukufudumala kweplanethi, ucwaningo olwenziwe e-Antarctica oluphethe ngokuthi ukufudumala kwembulunga yonke noma iplanethi kuhlale kuqala ngaphambi kwesikhathi seqhwa kufanele kubhekwe.
Njengoba usho, i-Ice Age yinto engalungiseki futhi enganqandeki:
“Konke lokhu kwenza umphakathi wezesayensi ucabange ukuthi, yize sibanga ukufudumala kwembulunga yonke okuntengantengayo ngesivinini esisheshayo kunemvelo, ngeke sikwazi ukumisa ukuphela kwesikhathi sezinhlanga ezehlukene nokufika kwenkathi entsha iqhwa. "
Unjiniyela uLee carroll, ezinkulumweni zakhe zokuhambisa amandla kaKryon, usimema ukuba silungiselele ukuqhwaqhaqha esivele sikuqalile kulo nyaka ka-2019.
Ubufakazi buthi, njengoba usho, kumarekhodi omoya abhajwe kumasilinda eqhwa e-Antarctica, nasezindandeni zezihlahla. Kusimema ukuthi sithuthukise ukwanela kwamandla ezingeni lendawo, emphakathini nasezindlini. Ngoba «igridi kagesi ayilungele ukumelana nenkathi yeqhwa. Kungase kwehluleke. Futhi kuzohluleka »