Tushen kankara

Tushen ƙanƙara shine ainihin samfurin da aka saba cirewa daga takardar kankara ko babban dutsen glacier. Tun lokacin da ƙanƙara ke fitowa daga haɓakar yawan dusar ƙanƙara na shekara-shekara, ƙananan yadudduka sun girmi na sama, kuma tushen ƙanƙara yana ɗauke da ƙanƙara da aka kafa tsawon shekaru. Ana haƙa maƙalli tare da augers na hannu (don ramukan da ba su da zurfi) ko na'urori masu ƙarfi; za su iya kaiwa zurfin sama da mil biyu (kilomita 3.2), kuma suna ɗauke da ƙanƙara har zuwa shekaru 800,000.

Ana iya amfani da abubuwan da ke cikin jiki na ƙanƙara da na kayan da aka makale a ciki don sake gina yanayin sama da kewayon shekarun ainihin. Matsakaicin isotope daban-daban na oxygen da isotope na hydrogen suna ba da bayanai game da yanayin zafin daɗaɗɗen, kuma ana iya yin nazarin iskar da ke makale a cikin ƙananan kumfa don sanin matakin iskar gas kamar carbon dioxide. Tunda zafin zafi a cikin babban kankara yana da sannu a hankali, zafin rijiyar burtsatse wata alama ce ta yanayin zafi a baya. Ana iya haɗa wannan bayanan don nemo samfurin yanayi wanda ya fi dacewa da duk bayanan da ke akwai.

Rashin ƙazanta a cikin ƙanƙara na iya dogara da wuri. Yankunan bakin teku sun fi dacewa sun haɗa da kayan asalin ruwa, kamar ions gishiri na teku. Cibiyoyin kankara na Greenland sun ƙunshi nau'ikan ƙurar da iska ke hura da su wanda ke da alaƙa da sanyi, bushewar lokatai a da, lokacin da sahara mai sanyi ke ta fama da iska. Abubuwan da ke da radiyo, ko dai na asali na asali ko kuma waɗanda aka ƙirƙira ta hanyar gwajin nukiliya, ana iya amfani da su zuwa kwanan wata yadudduka na kankara. Wasu al'amura masu aman wuta waɗanda ke da isassun ƙarfi don aika abubuwa a duniya sun bar sa hannu a cikin ma'auni daban-daban waɗanda za a iya amfani da su don daidaita ma'aunin lokacinsu.

Tun farkon karni na 20 ne aka yi nazari kan kankara, kuma an hako ma'adinan da yawa a sakamakon shekarar Geophysical ta kasa da kasa (1957-1958). An kai zurfin sama da 400 m, rikodin wanda aka fadada a cikin 1960s zuwa 2164 m a tashar Byrd a Antarctica. Ayyukan hako kankara na Soviet a Antarctica sun hada da shekaru da yawa na aiki a tashar Vostok, tare da zurfin zurfin da ya kai 3769 m. An kammala wasu zurfafan muryoyi da yawa a cikin Antarctic tsawon shekaru, ciki har da aikin Ice Sheet na Yammacin Antarctic, da ma'adinan da Binciken Antarctic na Biritaniya ke gudanarwa da Balaguron Kimiyya na Trans-Antarctic na kasa da kasa. A cikin Greenland, jerin ayyukan haɗin gwiwa sun fara a cikin 1970s tare da Aikin Ginshin Kankara na Greenland; akwai ayyuka da yawa na bin diddigin, tare da na baya-bayan nan, Aikin Gabashin Greenland Ice-Core Project, da farko ana tsammanin kammala babban cibiya a gabashin Greenland a cikin 2020 amma tun da aka jinkirta shi.Berwyn, Bob (27 March 2020). "Coronavirus Already Hindering Climate Science, But the Worst Disruptions Are Likely Yet to Come". Retrieved 5 April 2020.

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