Ukuqaqamba

Utshintsho lwemozulu lubeka ukuthandabuza okukhulu kwizinto ezifunyaniswe zizazinzulu malunga glaciations. Into ke kukuba ngo-2004 sasibanda kakhulu ebusika, sinemvula encinci nemililo yamahlathi eyanwenwa kwihlabathi liphela. Ezi nyaniso zenze ingxoxo phakathi kwesayensi malunga nemijikelo yomoya kunye nemingcipheko enokubakho enxulumene nokutshintsha kwemozulu. Kukho abo bathandayo ukuba ukufudumala kwehlabathi ayisiyonto ibangelwa ngabantu, kodwa iyahambelana nomnye umjikelo wokugqibela wokuqhawuka komkhenkce onomhlaba wethu amaxesha ngamaxesha.

Kule nqaku siza kukuxelela yonke into ofuna ukuyifumana malunga ne-glaciation kunye nobudlelwane babo notshintsho lwemozulu.

Ukutsala kubushushu

Kuyaziwa ukuba kwinkulungwane ephelileyo imozulu yeplanethi iye yafumana ukonyuka kwamaqondo obushushu aphakathi. Oku kungenxa yokwanda uxinizelelo lwekharbhon diokside kunye nezinye iigesi zegreenhouse ngomthamo wokugcina ubushushu emoyeni. Ingxaki kukuba kukho abantu abathi iplanethi yethu inee-glaciation zemijikelezo. Kuyinyani ukuba kuyo yonke indalo eplanethi yethu kuye kwakho imijikelezo yokuqhekeka kwamaxesha kunye namaxesha e-glacial. Nangona kunjalo, ingxaki iqala xa simisela okwahlukileyo ukuhlalutya isantya sale glaciation kunye nobushushu behlabathi ngaphambi kwazo.

Njengoko kunokubonwa kulandelelwano lwe-glaciation, esiza kubona kamva, ixesha elidlula phakathi kokuqhekeka kwelinye kunye nelinye lide ngokwaneleyo ukuba zonke iintlobo zezilwanyana kunye nezityalo kunye ne-morphology ye-ecosystems ikwazi ukuziqhelanisa notshintsho indlela eyiyo. Kule meko, sithetha ngayo ukwanda kwamaqondo obushushu aphakathi kwihlabathi ngexesha elifutshane kakhulu. Ixesha elifutshane kwaye iintlobo azinalo ixesha lokuziqhelanisa kwaye ziqala ukunciphisa inani labo. Oko ke kukuncipha kwabantu kangangokuba uninzi lwabo luye lwanyamalala.

Ukuze kupheliswe onke amathandabuzo, siza kubeka etafileni izinto ezithile malunga nexesha elidlulileyo kunye neziphumo zenzululwazi ezifunyenweyo. Ezi zinto zifunyanisiweyo zidibanisa zonke iindlela zendalo ezibonakala ngathi zinempembelelo kwimozulu yesijikelezi-langa. Kufuneka kuthathelwe ingqalelo ukuba, ngokuzimeleyo kwimpembelelo yezinto ezenziwa ngabantu, izazinzulu ziyavuma njengezona zinto zibangela indalo ekuguqukeni kwemozulu i-wobble ye-axis yoMhlaba yokujikeleza. Utshintsho kumjikelezo woMhlaba ojikeleze ilanga nazo ziye zongezwa koku. Kungenxa yokuba yonke iseti yeentshukumo iguqula ukuhanjiswa kwamandla afunyanwa yiplanethi yethu elangeni.

Iminyaka ye-Ice kunye notshintsho kumjikelezo woMhlaba

Ukuze wazi amaxesha e-glacial kunye ne-gl glaciers, ubushushu bemo yonyaka kufuneka buvavanywe ngokwembono yejoloji. Ithiyori kaMilankovitch yeyona ichaza ukuba kukho utshintsho kwimozulu yesijikelezi-langa emva kokubonakala kwamaGlaciations ngamaxesha athile. Kulapha apho kuye kwavela amaxesha amakhulu omkhenkce kunye namaxesha amancinci okuhlangana. Sithetha nje sikwixesha eliphakathi.

La maxesha okuqaqanjelwa ngumkhenkce kwenzeka ngenxa ye- indibaniselwano yemijikelo emi-3 yendalo iphela apho ukujikeleza komhlaba kuguquka ukusuka kwisetyhula kuye kwi-elliptical nangenye indlela. Kukho irekhodi lokuba enye yeendlela zokuqala ze-cosmic zenzeka phakathi kwe-90.000 kunye ne-100.000 kwiminyaka eyadlulayo. Kulapho umhlaba watshintsha ukujikeleza kwawo ukusuka kwisetyhula ukuya kwi-elliptical nangokuphambene. Omnye umjikelo we-cosmic wenzeka malunga neminyaka engama-26.000 kwaye wagqiba ukubetheka kwe-axis yomhlaba yokujikeleza. Okokugqibela, omnye umjikelo we-cosmic weminyaka engama-41.000 yenzekile apho ukutyekela kwe-axis yomhlaba malunga nenqwelomoya ye-orbit oscillates phakathi kwe-22.5 kunye ne-24.5 degrees.

Imijikelo yeCosmic

Lonke olu tshintsho kwiintshukumo kunye ne-axis yomhlaba zezona zinto zivelisa eyona glaciation. Kufuneka ithathelwe ingqalelo ukuba izigaba apho ukujikeleza komhlaba kuyisetyhula kwakamsinya nje ukuba kubekho utshintsho unyaka wonke. Nangona kunjalo, xa i-orbit illiptical, kukho ukusondela okukhulu ngamaxesha athile onyaka. Okwangoku, siyazi ukuba ukujikeleza komhlaba ngokubhekisele elangeni kuyinto elliptical, nangona ingekho kubuninzi bayo ngaphandle kokuqina. Xa umhlaba ugqitha kwi-perihelion, le yeyona ndawo ijikelezayo elangeni, yenzeka ekuqaleni kukaJanuwari. Ngeli xesha kusebusika kumantla e-hemisphere. Kwelinye icala, xa ise-aphelion kusesehlotyeni kumantla e-hemisphere, nangona ikwindawo ekude kakhulu.

Imijikelezo yendalo iphela izakuqhagamshela olu tshintsho, ngaphezulu kwexesha le-perihelion lwenzeka ngokuhambelana nobusika be-austral endaweni ye-boreal. Kuyaziwa ke ngoko ukuba isitshixo sempembelelo kwezi nguqu zomzimba kwinkangeleko ye-glaciation iyavumelana nemodeli yaseMilankovitch. Kwaye yonke into ibonakala inxulumene nexesha apho isangqa sijikeleza khona kwaye umgama ukusuka emhlabeni awufani tu. Kule meko, kushushu ehlotyeni njengangoku akwenzeki. Kwelinye icala, kumanqanaba apho i-orbit illiptical kwaye ine-eccentricity yayo ephezulu, ihlobo elishushu elifana neli likhoyo ngoku.

Xa i-orbit isetyhula ngakumbi Ithintela ikhephu ekunyibilikeni kwaye ngokuthe ngcembe iqokelela unyaka nonyaka. Oku kukhokelela umhlaba kwixesha elitsha lomkhenkce. Oku kuthathwa njengesiphelo sokuba into emisela ukuqaqanjelwa ngumkhenkce ayibobusika obuqatha kakhulu, kodwa lelona hlobo lipholileyo. Ukusuka apha ulwazi luyekiswa ukuba ngenxa yehlobo elipholileyo, umphezulu womkhenkce awuzukuvela kwaye unyaka nonyaka imithambo yomkhenkce esecaleni iyonyuka kubuninzi kude kube sekupheleni kobudala bomkhenkce.

Iminyaka eyaziwayo yomkhenkce eMhlabeni

Olu luhlu lokwahluka okwahlukileyo okwaziyo iplanethi yethu kwimbali yonke:

• I-glaciation yokuqala yaziwa njenge I-Huronian. Yenzeka malunga neminyaka eziibhiliyoni ezi-2.400 eyadlulayo. Yahlala malunga nezigidi ezingama-300 zeminyaka kwaye yayiyeyona inde kunazo zonke.
• I-glaciation yesibini yaziwa njenge Cryogenic. Inokuba yeyona inzima kwaye yenzeka malunga neminyaka ezizigidi ezingama-850 eyadlulayo. Yayinoxanduva lokuqhuma okulandelayo kweCambrian.
• I-glaciation yesithathu yaziwa njenge IAndes-iSahara. Kwenzeka malunga neminyaka engama-460 yezigidi edlulileyo.
• I-glaciation yesine ibizwa ngegama IKaroo kwaye kwenzeka malunga neminyaka engama-350 yezigidi eyadlulayo.
• Kwi-glaciation yangoku, ebizwa Glaciation koqeqeshoIkhe yabona ixesha lomkhenkce elimalunga neminyaka engama-40.000.

Ndiyathemba ukuba olu lwazi ungafunda ngakumbi malunga nokukhanya.