Kwiplanethi yethu kukho iziqwenga zomkhenkce ezigubungele iipali ezisentla nezasezantsi. Lo mkhenkce awukho elwandle kuphela kodwa uyafumaneka nakwiintaba. La maqhekeza omkhenkce aziwa njenge Umkhenkce. Xa la maqhekeza omkhenkce efikelela kubukhulu obukhulu kangangokuba ahlala egubungela iindawo ezigcweleyo nezibanzi, ayabizwa iminqwazi yomkhenkce.
Kule nqaku siza kukuxelela zonke iimpawu, ukubaluleka, amandla ezi cap polar kwaye kuya kwenzeka ntoni ukuba onke la maqhekeza omkhenkce aphela enyibilika.
Ukusekwa komkhenkce
Ukwenza indlela yee-cap polar, okokuqala kufuneka kwaziwe ukuba zenziwa njani na umkhenkce omkhenkce ukuze zisasazeke ngendlela yokuba ekugqibeleni zakhe i-cap polar. Lonke ukhenketho lomkhenkce olusasazeke ngexesha lokugqibela glaciation okanye ice age yenza umkhenkce omkhenkce. La maqhekeza omkhenkce abaluleke kakhulu njengeearhente zokukhukula kunye nabakhi besiqabu, umhlaba kunye nokuma komhlaba.
Esinye isizathu sokuba zibalulekile kukuba zenza umthombo wamanzi amatsha kwiiplanethi. Zininzi izinto eziphilayo ezisebenzisa ithuba lokunyibilika kwamanzi eqhwa ukuze zihlale ziphila, zivelise okanye zenze indawo yazo yokuhlala.
La maqhekeka omkhenkce akhiwa ngokuqokelelana, unyaka nonyaka, ikhephu eliwela ezantsi nasemathambekeni eentlambo. Zimi kwiindawo eziphakamileyo zeentaba. Ubunzima bunokufikelela kwinxalenye enkulu ukuba ikhephu elahlekileyo ngenxa yeqhwa lasehlotyeni lingaphantsi kwelo liqokelela ngexesha lekhephu.
Ubunzima becompact beli khephu buveliswa kuba ikhephu ngalinye licinezelwe kwelo lalifudula lifakwa ngaphambili. Ukuba ubushushu bunyibilike buye baphumelela ekunyibilikiseni umkhenkce, uyakuwubangela ukuba ubambe kwaye uqalise ukushukuma usiya emazantsi entlambo.
Ukuxinana kwekhephu kuhlala kunyuka ngobunzulu njengoko kukho isixa esikhulu sekhephu kwiyunithi nganye, ukuba compact ngakumbi. Eli phunga banalo sisiseko seqhwa kwaye lihamba ngokungathi lilwelo. Ngaphakathi kwiqhekeza lomkhenkce lihamba ngokukhawuleza kunendawo ezisecaleni, ke kuhlala kukho ikhefu, ukuxinana kunye nokuzolula okwenza ukuba kubonakale iintanda eziphezulu.
Imicimbi ye-Glacial dynamics
Umkhenkce uyashenxisa kwaye unyothule amatye aqikelelweyo asendleleni yawo. Amaqhekeza amatye abangelwa yile ntshukumo yomkhenkce abizwa ngokuba yimainaines. Indawo ekupheleni komkhenkce kulapho kuye kwenziwa khona i-thaw. Apha, ungabona ukuyilwa kweentaba ezincinci ezibizwa ngokuba yi-moraine yesiphelo.
Logama nje umkhenkce ugcina indawo yokuqokelela kwindawo ephezulu yekhephu kwimvula, umjikelo womkhenkce uya kuhlala uphila. Okokugqibela, kwindawo esezantsi, umkhenkce uyanyibilika, wenze imijelo emincinci yamanzi amatsha.
Kukho amaqhekeza omkhenkce ahamba kwiintlambo ezinyaweni zenkqubo yentaba. Xa bedibanisa ukwenza i-glacier enkulu yaziwa ngokuba yi-piedmont.
Iminqwazi Polar kunye ice cap
Nje ukuba siqonde ukuba yintoni i-glacier, ukuba yenzeka njani kwaye yeyiphi na i-dynamics yayo, siyaqhubeka nokuchaza ii-ice polars. Ukuba umkhenkce okhankanywe ngasentla ugubungela iithafa zokwenene kunye neziqithi eziphakamileyo nezisezantsi, yaziwa ngokuba yipop polar. Ezi migqomo zasemazantsi zihlala zizalwa kwiialpine glaciers kwaye ziyehla ezintlanjeni. Ekugqibeleni, bafikelela elwandle ngamanye amaxesha.
Ukuba umkhenkce mkhulu kangangokuba ugquma umphezulu welizwekazi liphela, ubizwa ngokuba ngumkhenkce kwilizwekazi. Oku kwenzeka kwimithambo yomkhenkce ese-Arctic nase-Antarctica. Lo maleko mkhulu womkhenkce uphumela ngaphandle ude ufike kwiilwandlekazi kwaye kulapho uqhekeka kubungakanani obahlukeneyo obenza icebergs.
Igama elithi polar caps lisetyenziselwa ukuchaza iindawo ezahlukeneyo zomkhenkce ezifumaneka eAntarctica naseGreenland. Ke, Nanini na xa sithetha ngokufudumala kwehlabathi okanye utshintsho lwemozulu sithetha ngokunyibilika komkhenkce osemkhenkceni. Ezi caps zemiqolo yomibini kuzo zombini iipali zenziwa kwiPleistocene ice age, kwixesha lamaQuaternary kwaye zeza kugubungela uninzi lwenyakatho yomhlaba.
I-cap polar yaziwa ngokuba yingubo yomkhenkce kwaye ihlala inokongezwa ngaphezulu kwe-1,8 yezigidi zeekhilomitha zesikwere somhlaba. Ngokobungakanani, zikwi-2.700 yeemitha ubuninzi. Ezi minqwazi zepolar zigubungela uninzi lobuso eGreenland. Umandlalo uvela kuphela ecaleni konxweme apho umkhenkce ungomelelanga ngokwaneleyo kwaye uqhekeka wenza iilwimi zomkhenkce. Xa iilwimi zifikelela elwandle, ziyaqhekeka zisiqhekeza somkhenkce ngexesha lonyaka loncibilike, zenze icebergs
Ii-Icebergs zinezinto zazo eziguqukayo kwaye ziyanyamalala kule minyaka idlulileyo. Ikepusi yePolar yale nto igubungela iAntarctica, kuphela leli glacier Inommandla wezigidi ezili-13 zeekhilomitha ezizikwere.
Kuza kwenzeka ntoni ukuba i-cap polar iyanyibilika?
Ngotshintsho lwemozulu kunye nokwanda kwempembelelo yegreenhouse, kukho intetho yokunyibilika komkhenkce omkhenkce. Iziphumo zangoku kukuba inqanaba lolwandle liyakunyuka. Cinga ukuba ingumkhenkce iqokelele phantse iipesenti ezingama-70 zawo onke amanzi acocekileyo emhlabeni. Ukuba la manzi, leyo iphezu komhlaba iphela inyibilika, iyakuphelela elwandle.
Izazinzulu ziqikelela ukuba ngonyaka wama-2100, Amanqanaba olwandle aya kunyuka nge-avareji yeesentimitha ezingama-50 ukusuka kwinqanaba lolwandle. Oku kuthetha ukuba iidolophu ezininzi ezingaselunxwemeni ziya kuchaphazeleka ngendlela engeyiyo kwaye ezinye iinkqubo zendalo ziya kulungiswa kwakhona. Ukongeza, i i-albedo yomhlaba iyakuchaphazeleka kuba kukho umhlaba omhlophe ongaphantsi obonisa izehlo zemitha yelanga.
Ndiyathemba ukuba olu lwazi ungafunda ngakumbi malunga neekepusi ze-polar kunye neziphumo zokunyibilika kwazo.