Yammacin Antarctic Ice Sheet

Yammacin Antarctica Ice Sheet (WAIS) shi ne ɓangaren kankara na nahiyar da ke rufe Yammacin Antárctica, ɓangaren Antarctica a gefen Dutsen Transantarctic wanda ke cikin Yammacin Hemisphere. An rarraba shi azaman kankara na ruwa, ma'ana cewa gadonsa yana ƙasa da matakin teku kuma gefensa suna gudana cikin ɗakunan kankara masu iyo. WAIS tana da iyaka da Ross Ice Shelf, Ronne Ice Shelf. 

A matsayin ƙaramin yanki na Antarctica, sauyin yanayi kuma ya fi shafar WAIS. An sami ɗumama kan takardar ƙanƙara tun daga shekarun 1950,   da kuma koma bayan glaciers na bakin teku tun aƙalla shekarun 1990.  Ƙididdiga sun nuna an ƙara shi a kusa   zuwa hawan tekun duniya tsakanin 1992 da 2017,  kuma yana asarar ƙanƙara a cikin 2010s a wani adadin daidai da  na hawan teku na shekara-shekara.  Yayin da wasu hasarar da aka yi ke samu ta hanyar haɓakar kankara ta Gabashin Antarctica, Antarctica gaba ɗaya za ta iya rasa isasshen kankara ta 2100 don ƙara  zuwa matakan teku. Bugu da ari, rashin kwanciyar hankali na kankara na ruwa na iya ƙara wannan adadin ta dubun santimita, musamman a ƙarƙashin ɗumamar girma.  Ruwan narkewar ruwa daga WAIS kuma yana ba da gudummawa ga matsewar teku kuma yana lalata samuwar ruwan ƙasan Antarctic mai gishiri, wanda ke haifar da rugujewar ruwan tekun Kudancin Tekun .   

dogon lokaci, Yammacin Antarctic Ice Sheet na iya ɓacewa saboda dumama wanda ya riga ya faru. Shaidar Paleoclimate ta nuna cewa wannan ya riga ya faru a lokacin Eemian, lokacin da yanayin zafi na duniya yayi kama da farkon karni na 21. An yi imanin cewa asarar kankara zai faru tsakanin shekaru 2,000 da 13,000 a nan gaba,   kodayake ƙarni da yawa na hayaki mai yawa na iya rage wannan zuwa shekaru 500.    in) na hauhawar matakin teku zai faru idan kankara ta rushe amma ta bar kankara a kan duwatsu a baya. Jimlar hauhawar matakin teku daga Yammacin Antarctica yana ƙaruwa zuwa   ft 1 in) idan sun narke, amma wannan zai buƙaci matakin zafi mafi girma. Isostatic rebound na ƙasar da ba ta da kankara na iya ƙara kusan 1  ft ) zuwa matakan teku na duniya a kan wasu shekaru 1,000.

Adana WAIS na iya buƙatar ci gaba da rage yanayin zafi na duniya zuwa " 1 ° C (1.8 ° F) ƙasa da matakin preindustrial, ko zuwa 2 ° C (3.6 ° F) a ƙasa da zafin jiki na 2020. Saboda rushewar kankara za ta kasance ta hanyar asarar Thwaites Glacier da Pine Island Glacier, wasu sun ba da shawarar shiga tsakani don adana su. A ka'idar, ƙara dubban gigatonnes na dusar ƙanƙara da aka kirkira na ɗan adam zai iya tabbatar da su, amma zai zama da wahala sosai kuma bazai lissafa ci gaba da hanzarin dumamar teku a yankin ba. Sauran sun ba da shawarar cewa gine-ginen da ke hana ruwan dumi a ƙarƙashin kankara zai iya jinkirta ɓacewar kankara ta ƙarni da yawa, amma har yanzu zai buƙaci ɗaya daga cikin manyan ayyukan injiniyan farar hula a tarihi.

 Bayyanawa 
The total volume of the entire Antarctic ice sheet is estimated at 26.92 million km3 (6.46 million cu mi),Fretwell, P.; et al. (28 February 2013). "Bedmap2: improved ice bed, surface and thickness datasets for Antarctica" (PDF). The Cryosphere. 7 (1): 390. Bibcode:2013TCry....7..375F. doi:10.5194/tc-7-375-2013. S2CID 13129041. Archived (PDF) from the original on 16 February 2020. Retrieved 6 January 2014. while the WAIS contains about 2.1 million km3 (530,000 cu mi) in ice that is above the sea level, and ~1 million km3 (240,000 cu mi) in ice that is below it. The weight of the ice has caused the underlying rock to sink by between  in a process known as isostatic depression.

A karkashin ƙarfin nauyin kansa, kankara yana lalacewa kuma yana gudana a hankali a kan dutse mai laushi. Yankunan kankara sune wuraren da motsi na kankara yake da jinkiri saboda an daskare shi zuwa gado, yayin da kogunan kankara ke gudana da sauri saboda akwai ruwa mai ruwa a cikin turɓaya a ƙarƙashin su. Wadannan ko dai ruwan da ke cikin ruwa wanda aka yi amfani da shi don rufe ƙasa ta teku kafin kankara ta daskare a sama da su, ko kuma an halicce su ne saboda rushewa daga rikici-rikice na kankara a kan dutse. Ruwa a cikin waɗannan turɓaya yana kasancewa ruwa saboda ɓawon duniya a ƙarƙashin kogunan kankara yana da ƙanƙara kuma yana gudanar da zafi daga aikin geothermal, kuma saboda friction kuma yana haifar da zafi, musamman a gefen tsakanin kogunan kansar da kankara.

Lokacin da kankara ta kai ga bakin teku, ko dai tana haifar da maraƙi ko ci gaba da gudana a waje zuwa cikin ruwa. Sakamakon shi ne babban, mai iyo kankara da aka sanya a nahiyar. Wadannan kankara suna hana kwararar kankara zuwa cikin teku muddin suna nan.

 Manazarta