Kwarin glacier, wanda kuma aka sani da kwarin ƙanƙara, yana nufin kwaruruka inda manyan glaciers ke yawo ko sau ɗaya ana zagayawa, suna barin filaye masu haske. A glacier kwarin Yana da matukar mahimmanci ga bambancin halittun halittu da ma'aunin muhalli.
Saboda wannan dalili, za mu gaya muku duk abin da kuke buƙatar sani game da abin da kwarin glacial yake, halayen geomorphology.
Menene kwarin glacial
Kwarin glacial, wanda kuma aka fi sani da glacial troughs, su ne waɗancan kwaruruka waɗanda za mu iya gano cewa sun bar baya da nau'ikan taimako na glaciers.
A takaice dai, kwaruruka masu kankara kamar kankara suke. Ana kafa kwaruruka na glacial lokacin da ƙanƙara mai yawa ta taru a cikin cirques na glacial. Ice daga ƙananan yadudduka daga ƙarshe ya motsa zuwa kasan kwarin, inda a ƙarshe ya zama tafki.
Ɗaya daga cikin manyan abubuwan da ke cikin kwarin glacial shine cewa suna da sashin giciye mai siffa mai siffa, wanda shine dalilin da ya sa ake kiran su da glacial. Wannan siffa ita ce babban fasalin da ke ba masana kimiyya damar bambance ire-iren wadannan kwaruruka inda yawan kankara ke zamewa ko kuma zamewa. Sauran alamomin kwarin dusar ƙanƙara su ne lalacewa da alamun hakowa fiye da kima, wanda ke haifar da ɓarkewar ƙanƙara da ja da kayan.
Tsohuwar dusar ƙanƙara a duniya sun ajiye kayan da ƙanƙara ta ruɓe a baya. Wadannan kayan suna da yawa iri-iri, kuma gabaɗaya sun zama daban-daban nau'ikan morai, irin su morai na kasa, moraine na gefe, tumbling moraines, har ma mafi muni, tsakanin abin da shahararren tafkin glacial yawanci ya kasance. Misalai na karshen su ne tafkunan glacial da za mu iya samu a gefen tsaunukan Turai (wanda ake kira Como, Mayor, Garda, Geneva, Constanta, da dai sauransu) ko a wasu yankunan tsakiyar Sweden da sauransu.
Dynamics na kwarin glacial
Dangane da tsarin zaizayar dusar ƙanƙara, yana da mahimmanci a nuna cewa glaciers suna da ƙura sosai kuma suna iya aiki azaman bel na isar da kayayyaki na kowane girma da gangaren ke bayarwa, suna jigilar su zuwa kwaruruka.
Har ila yau, akwai adadi mai yawa na narke ruwa a cikin glacier, wanda zai iya yaduwa cikin sauri a cikin ramukan da ke cikin glacier, yana loda kayan a kasan glacier, kuma waɗannan igiyoyin subglacial suna da tasiri sosai. Kayan da yake ɗauka yana haifar da ɓarna, kuma duwatsun da ke cikin glacier za a iya murƙushe su zuwa gauraya mai kyau na siliki da garin yumbu mai kankara.
Glaciers na iya aiki ta manyan hanyoyi guda uku kuma sune: fara glacial, abrasion, tura.
A cikin fashewar toshewar dutsen, ƙarfin rafin kankara na iya motsawa kuma ya ɗaga manyan ɓangarorin gadon gado. A haƙiƙa, madaidaicin bayanin gadon glacier ba shi da ka'ida sosai, tare da yankuna waɗanda ke faɗaɗa da zurfafa ta cikin nau'ikan baƙin ciki da ake kira tudun ruwa ko tudun ruwa, waɗanda ke zurfafawa ta hanyar tono ƙasa da ƙasa da tsayin daka. Sai a rage yankin kuma ana kiransa latch ko bakin kofa.
A cikin ɓangaren giciye, ana yin dandamali a cikin duwatsu masu ƙarfi waɗanda ke bajewa a wani tsayin tsayi, wanda ake kira pad ɗin kafada. Abrasion ya haɗa da niƙa, gogewa, da niƙa na gado ta wurin guntun dutsen da ke ɗauke da ƙanƙara. Wannan yana haifar da karce da tsagi. A cikin gogewa, shine mafi kyawun abubuwa, kamar yashi akan dutse.
A lokaci guda, saboda abrasion. Ana murƙushe duwatsu, suna samar da yumbu da silt, wanda aka fi sani da foda kankara saboda girman hatsi mai kyau, wanda ke ƙunshe a cikin ruwan narke kuma yana da kamannin madarar madara.
Ta hanyar matsawa, dusar ƙanƙara tana jigilarwa da turawa kanta abin da yake ruɓe wanda yake murƙushewa ya canza kamar yadda aka bayyana a sama.
siffofin zaizayar kasa
Daga cikinsu an gane su circuses, tarn, ridges, ƙaho, wuyansa. Lokacin yin ƙirar kwaruruka na dusar ƙanƙara, sukan mamaye kwaruruka da suka rigaya, waɗanda ke faɗaɗa da zurfafa cikin siffar U. Glaciers sun gyara tare da sauƙaƙa masu lankwasa na kwarin na asali da ɓarnawar dutsen, suna haifar da manyan tudu masu triangular ko tarkace.
A cikin kwarin glacial na yau da kullun, ƙwanƙolin daɗaɗɗen ruwa suna bin juna, suna kafa sarƙoƙi na tafkuna waɗanda ke karɓar sunan iyayenmu lokacin da kwandunan suka cika da ruwa.
A gare su, Kwarin Hanging tsohon kwarin tributary ne na babban glacier. An yi bayaninsu ne saboda zaizayar dusar ƙanƙara ya dogara da kauri na kankara, kuma glaciers na iya zurfafa kwarinsu amma ba magudanar ruwa ba.
Fjords suna tasowa lokacin da ruwan teku ya shiga cikin kwarin glacial, irin su na Chile, Norway, Greenland, Labrador, da fjords na kudu a Alaska. Yawancin lokaci ana danganta su da kurakurai da bambance-bambancen lithological. Sun kai zurfin zurfi, kamar tashar Messier a Chile, wanda Yana da zurfin mita 1228. Ana iya bayyana hakan ta hanyar tono ƙanƙara da ya wuce kima a ƙarƙashin teku.
Glaciation kuma na iya kwaikwayi duwatsun da suka zama duwatsu irin na tumaki, waɗanda santsi, zagaye saman samansu yayi kama da garken tumaki da ake kallo daga tsayi. Girman su daga mita ɗaya zuwa dubun mita kuma an daidaita su tare da hanyar ruwan ƙanƙara. Gefen maɓuɓɓugar ƙanƙara yana da bayanin martaba mai santsi saboda tasirin niƙa, yayin da ɗayan gefen yana da bayanan angular da rashin daidaituwa saboda cire dutsen.
Sigogin tarawa
Gilashin kankara sun ja da baya tun daga shekarun da suka wuce, kimanin shekaru 18.000 da suka wuce, wanda ke nuna jin dadin da aka gada tare da dukkan sassan da suka sha a lokacin dusar kankara ta karshe.
Adadin glacial adibas ne na kayan da glaciers ke ajiye kai tsaye, ba tare da tsayayyen tsari ba kuma guntuwar su suna da striations. Daga ra'ayi na girman hatsi, suna da nau'i-nau'i daban-daban, wanda ya kama daga fulawa na glacial zuwa abubuwan da ba su da kyau wanda aka kwashe kilomita 500 daga yankinsu na asali, kamar waɗanda aka samu a Central Park a New York; a Chile, a San Alfonso, a cikin faifan Maipo. Lokacin da waɗannan adibas suka haɗu, suna yin tillites.
Ana amfani da kalmar moraine zuwa nau'o'i da yawa waɗanda suka ƙunshi galibin tsaunuka. Akwai nau'ikan moraine da dogayen tudu da ake kira drumlins. Moraine na gaba shine tudun da ke gaban glacier wanda ke tasowa a cikin baka lokacin da glacier ya tsaya tsayin daka a matsayi daya na shekaru ko shekaru da yawa. Idan ya ci gaba da gudana a kan glacier, laka za ta ci gaba da taruwa akan wannan shingen. Idan dusar ƙanƙara ta koma baya, ana ajiye wani nau'in moraine a hankali, wanda ake kira basal moraine, kamar yadda yake a cikin dausayin yankin Manyan Tafkuna na Amurka. A gefe guda, idan glacier ya ci gaba da ja da baya, babban gefensa na iya sake daidaitawa, ya samar da moraine mai ja da baya.
Moraines na baya suna kama da glaciers na kwari kuma suna ɗaukar laka tare da gefen kwarin, suna ajiye dogayen tudu. Moraine na tsakiya yana samuwa inda moraies biyu na gefe suka hadu, kamar a mahaɗin kwaruruka biyu.
Drumlins suna da santsi, tsaunuka siriri masu kama da juna waɗanda suka haɗa da adibas na morai waɗanda glaciers na nahiyar suka shimfiɗa. Suna iya kaiwa mita 50 da tsayin kilomita, amma yawancin sun fi ƙanƙanta. A cikin Ontario, Kanada, ana samun su a filayen da ke da ɗaruruwan ganguna. A ƙarshe, an gano nau'ikan da suka ƙunshi ɓangarorin glacial kamar kame, kame terraces da eskers.
Ina fatan cewa tare da wannan bayanin za ku iya ƙarin koyo game da menene kwarin glacial da halayensa.