Kwabezindaba sihlala sibona ukuthi izinguzunga zeqhwa ziyanyamalala ngenxa yokushintsha kwesimo sezulu. Inguzunga yeqhwa isisindo esikhulu seqhwa elicindezelweyo elakhekayo ngokuhamba kwezinkulungwane zeminyaka. Yinto ethatha isikhathi eside ukuyakha futhi enyamalalayo endabeni yamashumi eminyaka. Ama-glaciers anezinto eziyinkimbinkimbi zokutadisha nokubaluleka okukhulu kweplanethi.
Ungathanda ukwazi konke okuphathelene nezinguzunga zeqhwa nokubaluleka kwazo?
Izici zeqhwa
Njengoba kushiwo ngaphambili, iqhwa liqoqa unyaka nonyaka ngezendlalelo. Lezi zingqimba zicindezelwe isisindo sabo kanye namandla adonsela phansi. Yize kungenye yezinto ezinkulu kakhulu emhlabeni, izinguzunga zeqhwa ziyahamba. Ziyakwazi ukugeleza kancane njengemifula futhi zidlule phakathi kwezintaba. Ngalesi sizathu, kunezinhlobo ezithile zezintaba ezidalwa ngokuhamba kwezinguzunga zeqhwa.
Ngokufudumala kwembulunga yonke, ubukhona bezinguzunga zeqhwa incipha kakhulu. Ziwumthombo omkhulu wamanzi ahlanzekile emhlabeni, kanye nemifula namachibi. Inguzunga yeqhwa ibhekwa njengesivinini se-Ice Age yokugcina. Lokhu kungenxa yokuthi yize amazinga okushisa enyukile, awancibiliki. Bakwazile ukuzinakekela izinkulungwane zeminyaka futhi bafeza umsebenzi wabo wemvelo. Lapho i-Ice Age iphela, amazinga okushisa aphezulu ezindaweni ezingezansi abangele ukuthi ancibilike. Ngemuva kokunyamalala kwabo, bashiye amafomu omhlaba abukekayo njengezigodi ezimise okwe-U.
Namuhla singathola izinguzunga zeqhwa ebangeni lezintaba zawo wonke amazwekazi, ngaphandle kwe-Australia. Singathola futhi izinguzunga zeqhwa eziphakathi kwamabanga angama-35 ° enyakatho kanye nama-35 ° eningizimu. Yize izinguzunga zeqhwa zingabonakala kuphela ku- Izintaba Ezinamadwala, e-Andes, e-Himalaya, eNew Guinea, eMexico, eMpumalanga Afrika naseNtabeni iZard Kuh (Iran).
Uma sihlanganisa zonke izinguzunga zeqhwa emhlabeni, ziyakha I-10% yendawo isiyonke yomhlaba. Ngemuva kwezifundo eziningi, kuphethwe ukuthi ama-99% azo zonke izinguzunga zeqhwa enziwa ngezingqimba zeqhwa le-polar kusuka kuwo womabili ama-hemispheres. Lokhu kungenxa yokuthi umhwamuko wamanzi osemkhathini uhamba emhlabeni wonke. Ikakhulukazi e-Antarctica naseGreenland ungathola ama-ice sheet kuwo womabili ama-hemispheres.
Amandla we-Glacier
Ngokuvamile, izinguzunga zeqhwa zakhiwa ezindaweni eziphakeme zezintaba nasezifundeni eziphakeme. Ukuze kwakhiwe izinguzunga zeqhwa, udinga amazinga okushisa aphansi unyaka wonke nemvula enjengeqhwa. Ngezikhathi ezifudumele, iqhwa eliqongelelwe liqala ukuncibilika futhi liwele i-glacier liye ezansi. Lapho amanzi angamanzi eqoqana ezansi kweqhwa, agijimela kuwo abheke emthambekeni. Lokhu kunyakaza kwamanzi oketshezi kubangela ukuthi yonke inguzunga yeqhwa ihambe.
Kubizwa izinguzunga zeqhwa ezintabeni izinguzunga zeqhwa zase-alpine nalezo zezigxobo izigaxa zeqhwa. Lapho bekhipha amanzi ancibilikayo emazingeni okushisa aphakeme ngezikhathi ezifudumele, bakha imizimba ebalulekile yamanzi yezitshalo nezilwane. Ngaphezu kwalokho, amadolobha amaningi amancane ahlinzekwa ngamanzi avela ezinguzungeni zeqhwa. Amanzi aqukethe izinguzunga zeqhwa kangangokuba athathwa njengendawo yokugcina enkulu yamanzi ahlanzekile emhlabeni. Iqukethe kuze kube yizingxenye ezintathu kwezine zayo, ngaphezu kwemifula namachibi.
Ukuziqeqesha
Inguzunga yeqhwa iqala ukwakha lapho iqhwa liwa ngokuqhubekayo futhi lihlala lizinzile unyaka wonke. Uma iqhwa eliwile lingancibiliki ngenkathi efudumele, lizohlala lizinzile komunye unyaka. Lapho kuqala inkathi ebandayo, iqhwa elilandelayo eliwayo lifakwa phezulu, libeke isisindo kulo bese lakha olunye ungqimba. Ngemuva kokudlula kweminyaka ngokulandelana, izingqimba zeqhwa ezihlangene ezakha izinguzunga zeqhwa ziyatholakala.
Amakhekheba eqhwa awela ezintabeni futhi acindezela izingqimba zangaphambilini ngendlela eqhubekayo. Ukucindezela kubangela ukuthi iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde iphinde isetshenziswe, njengoba umoya ophakathi kwamakristalu uncipha. Amakristalu eqhwa aqhubeka nokukhula ngokwengeziwe. Lokhu kubangela ukuba iqhwa lihlangane futhi kwandise ukuminyana kwalo. Kwenye indawo lapho iyeka ukuqoqana khona, ingcindezi yesisindo seqhwa iba sengathi iqala ukwehla iye phansi. Le yindlela okwakhiwa ngayo uhlobo lomfula ogeleza esigodini.
Inguzunga yeqhwa ifinyelela ukulingana lapho inani leqhwa eligcinwayo lilingana elincibilikayo. Ngale ndlela, ingahlala ekusimeni okufanayo isikhathi eside. Uma uyihlaziya ngokuphelele, ungabona ukuthi ngaphezu komugqa ophakathi nendawo, uzuza isisindo esingaphezu kokwehlayo bese ngezansi ulahlekelwa ngaphezu kokuzuzayo. Ukuze izinguzunga zeqhwa zilinganise ngokuphelele kungadlula iminyaka engaphezu kwekhulu.
Izingxenye zeqhwa
Inguzunga yeqhwa yakhiwa izingxenye ezahlukahlukene.
- Indawo yokuqongelela. Yindawo ephakeme kakhulu lapho iqhwa liwela futhi liqoqeke khona.
- Indawo ye-Ablation. Kule ndawo izinqubo zokuhlangana nokuhwamuka zenzeka. Yilapho i-glacier ifinyelela khona ibhalansi phakathi kokukhuphuka nokulahleka kwesisindo.
- Ukuqhekeka. Yizindawo lapho i-glacier igeleza ngokushesha khona.
- AmaMoraines. Lawa ngamabhande amnyama akhiwa izidalwa ezakha emaphethelweni naseziqongweni. Amatshe ahudulwe yiqhwa ayagcinwa akhiwe kulezi zindawo.
- Isikhumulo. Kuphela ekugcineni kweqhwa lapho iqhwa eliqongelelekile liyancibilika khona.
Izinhlobo zezinguzunga zeqhwa
Ngokuya ngendawo nezimo zokwakheka, kunezinhlobo ezahlukahlukene zezinguzunga zeqhwa.
- Iqhwa le-Alpine. Njengoba kushiwo ngaphambili, yilawo akhiwa ezintabeni eziphakeme.
- Isekisi leqhwa. Yizakhiwo zekresenti lapho amanzi eqoqeka khona.
- Amachibi e-Glacial. Akhiwa ngamachibi wamanzi ezindaweni eziphansi kwesigodi seqhwa.
- Isigodi seGlacier. Kuyinto yokwakheka kokuma komhlaba okubangelwa isenzo esiqhubekayo sokuqhuma kolimi lweqhwa. Lokho kusho ukuthi, yonke indawo lapho iqhwa ligudluza isikhunta futhi lithola ubujamo.
Kukhona nezinye izinhlobo ezingavamile kakhulu zezinguzunga zeqhwa njenge I-Inlandsis, iDrumlins, Amachibi Okumbiwa, i-Foothill Glacier ne-Hanging Glacier.
Ama-glaciers ayizakhiwo eziyinkimbinkimbi zemvelo ezinokulinganisela okuqinile nomsebenzi obalulekile wezidalwa eziphilayo.