Njengoko sisazi, Umkhenkce Zikhulu, ziyingqimba kwaye ziyinyambalala yomkhenkce owenzeka emhlabeni ngomphumo wokuqokelelana, kokuxinana kunye nekristallisation yekhephu emva kweminyaka yokuntlitheka. Namhlanje siza kuthetha ngenxalenye enomdla yamaqhekeza omkhenkce. Imalunga nayo isekisi yomkhenkce. Ukubaluleka kwamaqhwa omkhenkce kuya kusiba ngakumbi nangakumbi kwimeko yotshintsho lwemozulu esizifumana sikuyo.
Kule nqaku siza kuchaza ukuba yintoni isekisi eseglacial kwaye ibaluleke kangakanani.
Dynamics yomkhenkce
Ukuqonda ukuba yintoni i-glacial cirque, kufuneka kuqala sazi ukuba i-glacier yenziwa njani. Xa ubungakanani bamanzi obumphunga ehlotyeni bugqithisile ngekhephu lonyaka isenzo siqala ukunyibilika. Ukuze kubekho umkhenkce kufuneka kubekho ukulingana okufanelekileyo kwesixa sekhephu esibekwe kumphezulu womhlaba ngokuchaseneyo nenani lekhephu elinyibilikayo okanye elumphunga.
Kukho iindidi ezininzi zomkhenkce kwihlabathi liphela. Iimo ezahlukeneyo zinokwahlulwa phakathi kohlobo ngalunye lomkhenkce. Umzekelo, Kukho umkhenkce onentili, i-niche, imilo ye-ice field, njl. Iimeko zemozulu esizifumanayo zikwachonga izinto xa kufikwa kumba wokubona ubume bomkhenkce. Ezi meko zinokuba shushu, shushu, okanye polar. Iimeko ezishushu zinefuthe kwinani lekhephu eliqokelelayo okanye elinyibilikayo. Kuxhomekeka kubushushu obuqhelekileyo esibufumana kwindawo enomkhenkce, sinokuba nokuqokelelwa kwekhephu kunye nokuxinana okukhulu kunokuba amaqondo obushushu ehla enyuka ngakumbi.
Okwangoku, I-10% yomphezulu weplanethi yethu igqunywe ngumkhenkce. Kwiminyaka yakudala yejoloji yayigqunywe ngama-30%. Kunokuthiwa luphawu lwendawo oluqokelela esona sixa sikhulu samanzi acocekileyo kwihlabathi. Yiyo loo nto ingozi yokusebenza kwayo kusondele okanye, ngenxa yoko, ukunyuka kwenqanaba lolwandle.
I-84% yawo wonke ummandla we-glacier use-Antarctica, ngelixa eseleyo yahlulwe yaba yiGreenland kunye nezinye iindawo ezinomkhenkce emhlabeni.
Yintoni isekisi yomkhenkce
Ngoku ekubeni sikhumbule indlela amandla e-glacier asebenza ngayo, singangena ngokupheleleyo kwi-glacial cirque. Isekisi yomkhenkce isekisi esekisini uhlobo lwesitya esinamatye esimile okweembombo Kubangelwa kukutyibilika rhoqo okanye ukurabha okanye umkhenkce ngesivumelwano okanye kwindawo ekufumba kuyo okanye kwindawo yokondla. Indawo eqokelelekayo yomkhenkce yinxalenye apho isixa sekhephu esibekiweyo sikhulu kakhulu kuneso siyanyibilika. Kwelinye icala, sinendawo ye-abrasion apho izinga lokunyibilika liphezulu kuneqondo lokuqokelela.
I-cirque ye-glacial ihlala ikwimo ye-amphitheatre okanye isitulo esinamacala achazwe ngakumbi okanye imiphetho emi nkqo. I-glacial cirque ihlala inamacandelo amabini anokubonwa ngokulula. Sinenxalenye eyahlulwe yi Ukuqhekeka okubizwa ngokuba yi-rimaya enqamlezileyo okanye ethe tye: apha sifumana icandelo elingezantsi, kulapho ikhephu nomkhenkce ongaphezulu uqokelela khona. Inxalenye ephezulu, kwelinye icala, inamathambeka amakhulu kwaye umkhenkce uxineke ngakumbi ngenxa yeqondo lobushushu elisezantsi.
Singafumana kwakhona indawo yokuncitshiswa kwendawo kwi-glacial cirque. Lo mmandla kulapho inkqubo yokunyibilika, ukuveliswa kunye nokuhlulwa kweqhwithi kwenzeka xa ungena elwandle.
Iimpawu ze-glacier cirque
Nangona kukho iindidi ezininzi ze-glacial cirque, zonke zibonakaliswa ngokuba neempawu ezithile ze-morphological ezisivumela ukuba sahlule ezo zezitya zolwamkelo zemilambo yeentaba. Phakathi kweempawu eziphambili sineendonga zayo ezingaphezulu. Zibekwe ngaphezulu kwe-bergschrund yomkhenkce omdala. Ezi ndonga zazingasikelwanga mda okanye zitshatyalaliswe kukukrala komkhenkce. Iithambeka zalo ziqengqeleke kakhulu kwaye umphezulu wazo awukho mgaqweni ngenxa yokuwa kweebhloko zomkhenkce eziya kuthi ngqo elityeni.
Kwelinye icala, sinomgangatho osezantsi we-glacial cirque. Inethambeka elisezantsi kakhulu kunelodonga. Kule mvelaphi singafumana amatye awahlukeneyo anodaka asuswe ngamandla esibhakabhakeni. Ngamanye amaxesha, sinokufumana iintambo ze-moraine ezifanayo kwicala lesithambeka. Emazantsi esekisi inokubumba okumile okanye ithe tyaba. Ukongeza, Ngokuxhomekeka kubume babo, banokuba nelinye okanye nangaphezulu amachibi omkhenkce.
Kwiiseksi ezimile okwe-amphitheatre, icandelo lomnqamlezo linecandelo elimile okwe-U.Ngasezantsi komda osezantsi wesekisi siyabona ukuba ithambeka ligxininiswa njani kuphawula ukuqala kwentlambo yomkhenkce.
Nangona kubonakala ngathi, i-berry ibaluleke kakhulu kwi-glacial cirque. Luqhekeko oluthe tyaba olwenzeka emkhenkceni kumacala emigca ye-glacial cirque. Olu qhekeko lunoxanduva lokwahlula umkhenkce osisigxina odityaniswe kumatye entaba ukusuka kumkhenkce oshukumayo womkhenkce ngokwawo.
Iqunube liyavula kwaye libhenca iliwa eliphakame ekuqaleni kwehlobo. Oku kungenxa yamaqondo obushushu aphezulu kunye nesiqalo sokunyibilika komkhenkce. Iliwa livela kutshintsho lobusuku nobusuku. Le mijikelezo iphindaphindayo yomkhenkce kunye nokunyibilika, phantsi kwentshukumo yeqabaka, ibangela ukuba iliwa linyibilike kancinci kancinci kwaye lenze ukuba iliwa elingaphezulu liwe. Yile ndlela amatye athatha ngayo ngokungaqhelekanga kwaye phantse iimilo ezisikiweyo ezimileyo.
Le mijikelezo yomkhenkce iphazanyiswe kukutshintsha kwemozulu. Isahlulo esinyibilikayo sonyuka ngaphezulu kakhulu kunesixa semvula ngendlela yekhephu enokuqokelela ekwaziseni ngomkhenkce.
Ndiyathemba ukuba olu lwazi ungafunda ngakumbi malunga neesekethe zomkhenkce.