Kumajelo eendaba sihlala sibona ukuba umkhenkce uyanyamalala ngenxa yokutshintsha kwemozulu. Umkhenkce sisixa esikhulu somkhenkce oxineneyo owenza kwisithuba samawaka eminyaka. Yinto ethatha ixesha elide ukuyakha kwaye iyanyamalala kumcimbi wamashumi eminyaka. Umkhenkce uneempawu ezintsonkothileyo zokufunda kwaye zibaluleke kakhulu kwiplanethi.
Ngaba ungathanda ukwazi yonke into enxulumene neqhwa kunye nokubaluleka kwazo?
Iimpawu zomkhenkce
Njengoko bekutshiwo ngaphambili, ikhephu liqokelela unyaka nonyaka ngokwamanqanaba. Ezi zahlulo zixinaniswe bubunzima bazo kunye nesenzo somxhuzulane. Nangona zizezinye zezinto ezinkulu emhlabeni, amaqhekeza omkhenkce ayahamba. Ziyakwazi ukuhamba kancinci njengemilambo kwaye zidlula phakathi kweentaba. Ngesi sizathu, kukho ezinye iintlobo zeentaba ezenziwe ngokuhamba komkhenkce.
Ngobushushu behlabathi, ubukho bomkhenkce incipha ngokuqatha. Bangumthombo wamanzi amatsha kwiplanethi, kunye nemilambo kunye namachibi. Umkhenkce uthathwa njengendawo eseleyo ye-Ice Age yokugqibela. Kungenxa yokuba nangona amaqondo obushushu enyukile, awanyibiliki. Baye bakwazi ukuzigcina ngokwamawaka eminyaka kunye nokufezekisa umsebenzi wabo wendalo. Xa i-Ice Age yaphela, amaqondo obushushu aphezulu kwiindawo ezisezantsi abangela ukuba anyibilike. Emva kokunyamalala kwabo, bashiye umhlaba omangalisayo onjengeentili ezimilise u-U.
Namhlanje sinokufumana amaqhekeza omkhenkce kwiinduli zeentaba zawo onke amazwekazi, ngaphandle kweOstreliya. Sinokufumana amaqhekeza omkhenkce phakathi kobubanzi obungama-35 ° emantla nangama-35 ° emazantsi. Nangona ii-glaciers zinokubonakala kuphela kwifayile ye- Iintaba ezinamatye, kwiintaba zeAndes, kwiiHimalaya, eNew Guinea, eMexico, eMpuma Afrika nakwiNtaba iZard Kuh (Iran).
Ukuba sidibanisa wonke umkhenkce ehlabathini, ayenzeka I-10% yommandla womhlaba uwonke. Emva kovavanyo oluninzi, kuye kwagqitywa kwelokuba i-99% yazo zonke ii-glaciers zenziwe ngamanqanaba e-polar ice kuzo zombini i-hemispheres. Kungenxa yokuba umphunga wamanzi okhoyo emoyeni uhambahamba kwihlabathi liphela. Ngokukodwa eAntarctica naseGreenland ungafumana amaqhekeza omkhenkce kuzo zombini iihemispheres.
Utshintsho kumandla omkhenkce
Ngokubanzi, amaqhwa omkhenkce ayanda kwiindawo eziphakamileyo zeentaba nakwiingingqi ezibandayo. Ukuze iqonga lomkhenkce lenze, kufuneka ubushushu obuphantsi unyaka wonke kunye nemvula ngendlela yekhephu. Ngamaxesha afudumeleyo, umkhenkce oqokelelweyo uqala ukunyibilika kwaye uhambe ngapha komkhenkce usiya ezantsi. Xa amanzi angamanzi eqokelelana emazantsi omkhenkce, abaleka kuwo esiya kwithambeka. Le ntshukumo yamanzi angamanzi ibangela ukuba wonke umkhenkce uhambe.
Iikhephu zentaba zibizwa iialpine glaciers nezozibonda iminqwazi yomkhenkce. Xa bekhupha i-meltwater kumaqondo obushushu aphezulu ngamaxesha ashushu, benza imizimba ebalulekileyo yamanzi kwizityalo nezilwanyana. Ukongeza, iidolophu ezininzi ezincinci zibonelelwa ngamanzi avela kumkhenkce. Amanzi aqulethwe ngumkhenkce kangangokuba athatyathwa njengowona mthombo mkhulu wamanzi acocekileyo emhlabeni. Iqulethe ukuya kwiikota ezintathu zayo, ngaphezulu kwemilambo kunye namachibi.
Uqeqesho
Umkhenkce uqalisa ukubakho xa ikhephu liwa ngokuqhubekayo kwaye lihlala lizinzile unyaka wonke. Ukuba ikhephu eliweleyo alinyibiliki ngexesha elifudumeleyo, liya kuhlala lizinzile komnye unyaka. Xa kuqala ixesha elibandayo, ikhephu elilandelayo eliwayo lifakwa ngaphezulu, libeka ubunzima kulo kwaye lenze olunye uluhlu. Emva kokudlula ngokulandelelana kweminyaka, izaleko zekhephu ezihlangeneyo ezenza umkhenkce ofumanekayo ziyafunyanwa.
Amakhekheba ekhephu awela ezintabeni kwaye acinezela umaleko odlulileyo ngendlela eqhubekayo. Ukucinezelwa kubangela ukuba 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 ibuye, Ukunyanzeliswa kubangela ukuba iphinde iphinde iphindwe kwakhona, njengoko umoya phakathi kwama-crystals uyancipha. Amakristali omkhenkce aqhubeka ekhula eba nkulu. Oku kubangela ukuba ikhephu lidibane kwaye lonyuse uxinano lwalo. Ngexesha elithile apho igqiba ukuqokelela khona, uxinzelelo lobunzima bomkhenkce kangangokuba luqala ukutyibilika luye ezantsi. Yile ndlela lwenziwa ngayo uhlobo lomlambo ohamba ngentlambo.
Umkhenkce ufikelela kumlinganiso xa isixa sekhephu esigcinwayo sinye sinyibilika. Ngale ndlela, inokuhlala kuzinzo olufanayo ixesha elide. Ukuba uhlalutye ngokupheleleyo, kuyabonakala ukuba ngaphezulu komgca ophakathi, ufumana ubunzima obungaphezulu kokulahleka kwakho kwaye ngezantsi ulahlekelwe ngaphezulu kokufumana. Ukuze i-glacier ibe ibhalansi epheleleyo kungadlula iminyaka eli-100.
Icandelo lomkhenkce
Umkhenkce wenziwe ngamacandelo ahlukeneyo.
- Indawo yokuqokelela. Yeyona ndawo iphakamileyo apho ikhephu liwela khona kwaye liqokelelene.
- Indawo yokurhoxisa. Kule ndawo, iinkqubo zokudityaniswa kunye nomphunga zenzeka. Yilapho i-glacier ifinyelela khona ukulinganisela phakathi kokunyuka kunye nokulahleka kobunzima.
- Iintanda. Yeyona mimandla apho umkhenkce ugeleza ngokukhawuleza.
- Moraines. Ezi ziibhanti ezimnyama ezenziwa zizidalwa ezakha emaphethelweni nakumphezulu. Amatye atsalwa ngumkhenkce ayagcinwa aze abunjwe kwezi ndawo.
- Indawo yokukhwelela. Sisiphelo esisezantsi somkhenkce apho ikhephu eliqokelelweyo liyanyibilika.
Iindidi zomkhenkce
Kuxhomekeka kwindawo kunye neemeko zokwakheka, kukho iintlobo ezahlukeneyo zomkhenkce.
- Umkhenkce weAlpine. Njengoko bekutshiwo ngaphambili, zezo zenziwe kwiintaba eziphakamileyo.
- Iiskisi zeGlacier. Ziifresenti apho amanzi aqokelelana khona.
- Amachibi eGlacial. Zenziwe kumachibi amanzi kwiindawo zokudakumba zentlambo yomkhenkce.
- Intili yeGlacier. Yindlela yokwakheka komhlaba ebangelwa kukuqhubeka kokukhukula kolwimi lomkhenkce. Oko kukuthi, yonke indawo apho umkhenkce utyibilika khona kwaye ufumane iimilo.
Kukho nezinye iintlobo ezingaqhelekanga zomkhenkce ezifana Inlandsis, Drumlins, Amachibi okumba, i-Foothill Glacier kunye ne-Hanging Glacier.
Umkhenkce zizinto ezintsonkothileyo zendalo ezinokulinganisela okungqongqo kunye nomsebenzi obalulekileyo wezidalwa eziphilayo.