Greenland kankara

 

Greenland kankara
ice sheet (en)
Bayanai
Bangare na	Arctic ice pack (en)
Ƙasa	Greenland
Located in protected area (en)	Northeast Greenland National Park (en)
Ƙasantuwa a yanayin ƙasa	Greenland (en)
Wuri
76°42′N 41°12′W

Tsarin kankara na Greenland ( Danish </link> , Greenlandic </link> ) ƙanƙara ce mai r kalmar kankara ta cikin gida, ko kuma daidai da Danish, indlandsis. Ana yawan amfani da GIS gagararre a cikin adabin kimiyya.

Ita ce ta biyu mafi girma a kan kankara a duniya, bayan takardar kankara ta Antarctic. Tsawon kankara kusan 2,900 kilometres (1,800 mi) mai tsayi a wajen arewa zuwa kudu, kuma mafi girman fadinsa shine 1,100 kilometres (680 mi) a wani latitude na 77°N, kusa da iyakar arewa. Matsakaicin kauri shine kusan 1.5 kilometres (0.9 mi) da fiye da 3 kilometres (1.9 mi) a mafi kauri. Baya ga babban kankara, ƙananan kankara (kamar Maniitsoq da Flade Isblink ) da kuma glaciers, sun rufe tsakanin 76,000 and 100,000 square kilometres (29,000 and 39,000 sq mi) kewaye da kewaye.

Canjin yanayi yana shafar takardar kankara ta Greenland. Ya fi fuskantar sauyin yanayi fiye da tudun kankara na Antarctic saboda matsayinsa a cikin Arctic, inda yake ƙarƙashin haɓakar dumamar yanayi . Duk da yake ana sa ran ɗan ƙaramin ɗan ƙaramin kankara zai narke a cikin ƙarni na 21, an yi imanin cewa mafi yawan ko ma dukkan kankara ɗin sun himmatu wajen narkewa a ƙarƙashin yanayi na yanzu ko kuma mai yiwuwa a nan gaba sai dai idan an juyar da ɗumamar kwanan nan. mai da shi misali na yanayin tipping point. Idan duka 2,850,000 cubic kilometres (684,000 cu mi) na kankara zai narke, zai haifar da hawan tekun duniya na 7.2 metres (24 ft), ko da yake ana tsammanin wannan zai ɗauki shekaru millennia don yin cikakken wasa.

Wannan raye-rayen da aka ba da labari yana nuna canjin da aka tara a cikin hawan kankara na Greenland tsakanin 2003 da 2012.

Gabaɗaya

Kasancewar ruwan kankara a cikin zurfin teku da aka gano daga arewa maso yammacin Greenland, a cikin Fram Strait, da kudancin Greenland yana nuna ci gaba ko ƙaranci kasancewar ko dai takardar kankara ko zanen kankara wanda ke rufe mahimman sassan Greenland na ƙarshe 18 shekaru miliyan. Daga kusan 11 shekaru miliyan da suka wuce zuwa 10 shekaru miliyan da suka wuce, an rage girman Sheet ɗin Kankara na Greenland sosai. Sheet ɗin kankara na Greenland ya samo asali a tsakiyar Miocene ta hanyar haɗin kankara da glaciers. An sami ƙaruwar glaciation a lokacin Late Pliocene . Ice takardar da aka kafa dangane da ɗagawa na West Greenland da Gabashin Greenland sama. Duwatsun Yamma da Gabashin Greenland sun ƙunshi ɓangarorin nahiyoyin da aka ɗaga su a matakai biyu, shekaru miliyan 10 da 5 da suka gabata, a zamanin Miocene . [upper-alpha 1] Yin ƙirar kwamfuta yana nuna cewa ɗagawa zai ba da damar glaciation ta haifar da haɓakar hazo na orographic da sanyaya yanayin zafi . Kankara mafi dadewa da aka sani a cikin kwandon kankara na yanzu ya kai shekaru 1,000,000. Gilashin kankara kuma suna yin rikodin tasirin ɗan adam, kamar gubar daga tsohuwar Girka da Daular Roma.

Nauyin kankara ya raunana tsakiyar yankin Greenland; saman bedrock yana kusa da matakin teku a kan mafi yawan ciki na Greenland, amma tsaunuka suna faruwa a kusa da gefen, suna rufe takardar tare da gefenta. Idan ƙanƙara ta ɓace ba zato ba tsammani, Greenland zai fi yiwuwa ya bayyana a matsayin tsibiri, aƙalla har sai isostasy ya sake ɗaga saman ƙasa sama da matakin teku. Dusar ƙanƙara ta kai tsayinsa mafi girma a kan kubba biyu masu tsayi na arewa-kudu, ko tudu. Kusar kudu ta kai kusan 3,000 metres (10,000 ft) a latitudes 63° – 65°N ; Dome na arewa ya kai kimanin 3,290 metres (10,800 ft) a kusan latitude 72°N ( "koli" na huɗu mafi girma na Greenland ). An raba matsugunan gidaje biyu a gabas da tsakiyar layin Greenland. Kankarar da ba ta da iyaka ba ta isa teku tare da wani faffadan gaba a ko'ina a cikin Greenland, ta yadda ba a sami babban rumbun kankara ba. Yankin kankara ya isa teku kawai, duk da haka, a cikin yankin da ba a saba gani ba a yankin Melville Bay kudu maso gabashin Thule, da kuma a cikin Jokel Bay . Manyan kanti glaciers, waɗanda ke da ƙayyadaddun harsuna na takardar kankara, suna motsawa ta cikin kwaruruka masu iyaka da ke kewayen Greenland don su koma cikin teku, suna samar da ɗimbin ƙanƙara da ke faruwa a wasu lokuta a cikin Arewacin Atlantic. Mafi sanannun waɗannan kantunan glaciers shine Jakobshavn Glacier ( Greenlandic </link> ), wanda, a ƙarshensa, yana gudana a gudun 20 to 22 metres (66 to 72 ft) a kowace rana.

Glaciologist a wurin aiki.

A kan takardar kankara, yanayin zafi gabaɗaya ya yi ƙasa sosai fiye da sauran wurare a Greenland, saboda tasirin gida na ra'ayoyin kankara-albedo . Mafi ƙanƙanta yanayin zafi na shekara-shekara, woce, kusan −31 °C (−24 °F), yana faruwa a arewa ta tsakiya na kurbar arewa, kuma yanayin zafi a bakin kurbin kudu yana kusan −20 °C (−4 °F) .</link> A ranar 22 ga Disamba 1991, zazzabi na −69.6 °C (−93.3 °F) an yi rikodin shi a tashar yanayi ta atomatik kusa da babban taron koli na Greenland Ice Sheet, yana mai da shi mafi ƙarancin zafin jiki da aka taɓa yin rikodin a Arewacin Hemisphere . Ba a lura da rikodin fiye da shekaru 28 ba kuma a ƙarshe an gane shi a cikin 2020.

Gilashin kankara a matsayin rikodin yanayi na baya

Masanin kimiyyar NASA Eric Rignot ya ba da labarin rangadi game da tudun kankara na Greenland.

Tushen kankara, wanda ya ƙunshi nau'in dusar ƙanƙara da aka danne daga shekaru sama da 100,000, yana ƙunshe a cikin ƙanƙara mafi daraja a yau na yanayin da suka gabata. A cikin shekarun da suka gabata, masana kimiyya sun hako kankara har zuwa 4 kilometres (2.5 mi) zurfa. Masana kimiyya suna da, ta yin amfani da waɗancan nau'ikan kankara, sun sami bayanai akan (proxies don) zafin jiki, ƙarar teku, hazo, sunadarai da abun da ke tattare da iskar gas na ƙananan yanayi, fashewar volcanic, canjin hasken rana, yawan amfanin ƙasa na teku, hamada da gobarar daji. Lalacewar ƙasa daga ~ 1.4 km (0.87 mi) ƙarƙashin ƙanƙarar da aka adana tun 1966 yana nuna cewa Greenland ba ta da ƙanƙara gaba ɗaya kuma tana tsiro aƙalla sau ɗaya a cikin shekaru miliyan da suka gabata. Ba a tsammanin wannan ba kuma yana iya nuna Greenland ta kasance mai rauni da kuma kula da sauyin yanayi fiye da yadda ake tunani a baya.

Sauyin yanayi na kwanan nan

Gabaɗaya la'akari akan ƙimar canji

Yanayin Yanayin Arctic 1981-2007

A cikin shekarun baya-bayan nan, wani yanki a Arewacin Atlantika ciki har da kudancin Greenland yana ɗaya daga cikin wurare guda ɗaya a duniya da ke nuna sanyi maimakon dumama, da Greenland sun nuna yanayin yanayin zafi mai rikitarwa fiye da sauran sassan duniya. Wani takarda na 2006 akan rikodin zafin jiki na Greenland ya nuna cewa shekarar da ta fi zafi a rikodin ita ce 1941 yayin da mafi kyawun shekarun da suka gabata shine shekarun 1930 da 1940. Bayanan da aka yi amfani da su sun fito ne daga tashoshi a kudu da bakin tekun yamma, yawancinsu ba su ci gaba da aiki ba a tsawon lokacin binciken. Koyaya, daga baya kuma ƙarin cikakkun bayanan bayanan sun kafa ɗumamar ɗumama sosai a cikin lokacin 1979-2005 (daidai da raguwar ƙanƙarar tekun Arctic a lokaci ɗaya da ra'ayin sa na kankara-albedo ) Kamar yadda Greenland Ice Sheet ya sami narkewar da ba a taɓa gani ba tun dalla-dalla. bayanan sun fara, kuma da alama za su ba da gudummawa sosai ga hawan teku da kuma yiwuwar sauye-sauyen zagayawan teku a nan gaba.

Ruwan narke a kusa da Greenland na iya jigilar abubuwan gina jiki da carbon carbon zuwa teku. Ma'auni na adadin baƙin ƙarfe a cikin meltwater daga takardar kankara na Greenland ya nuna cewa yawan narkewar daftarin kankara zai iya ƙara adadin wannan ƙananan sinadari zuwa Tekun Atlantika daidai da wanda ƙurar iska ke ƙarawa. Duk da haka yawancin barbashi da baƙin ƙarfe da aka samo daga glaciers a kusa da Greenland na iya kasancewa cikin tarko a cikin manyan fjords da ke kewaye da tsibirin kuma, ba kamar HNLC Kudancin teku ba inda baƙin ƙarfe ke da iyakacin ƙananan ƙwayoyin cuta, samar da halittu a Arewacin Atlantic. yana ƙarƙashin ƙayyadaddun iyaka na sarari da na ɗan lokaci kawai na ƙayyadaddun ƙarfe. Duk da haka, ana lura da yawan aiki a kusa da manyan kananun ruwa da ke kawo ƙarshen glaciers a kusa da Greenland kuma wannan ana danganta shi da abubuwan shigar da ruwa mai narkewa wanda ke haifar da haɓakar ruwan teku mai wadatar ma'adanai.

Asar Amirka ta gina wani sansani mai amfani da makamashin nukiliya a asirce, mai suna Camp Century, a cikin tudun kankara na Greenland. A cikin 2016, ƙungiyar masana kimiyya sun kimanta tasirin muhalli kuma sun kiyasta cewa saboda canjin yanayin yanayi a cikin 'yan shekarun da suka gabata, narke ruwa zai iya saki dattin nukiliya, lita 20,000 na sharar sinadarai da lita miliyan 24 na najasa da ba a kula da su ba a cikin muhalli. Duk da haka, ya zuwa yanzu babu Amurka ko Denmark da suka ɗauki alhakin tsaftacewar.

Ciwon sanyi da ake iya gani akan yanayin yanayin NASA na duniya na 2015, shekara mafi zafi da aka yi rikodin har zuwa 2015 (tun 1880) - Launuka suna nuna yanayin yanayin zafi ( NASA / NOAA ; 20 Janairu 2016).

Hanyoyin haɗi na waje

• Haqiqa yanayi na Greenland Ice
• Binciken Geological na Denmark da Greenland (GEUS) Archived 2009-09-26 at the Wayback Machine Archived </link> GEUS yana da kayan kimiyya da yawa akan Greenland.
• Jami'ar Jihar Emporia - James S. Aber Lecture 2: Gilashin Kankara na Zamani da Sheets na Kankara.
• Ƙimar Tasirin Yanayin Arctic
• GRACE ma'aunin girman kankara: Archived 2009-03-27 at the Wayback Machine Archived </link> "Ƙasashen Ice Mass Mass Flux na Kwanan nan daga SpaceborneGravimetry"
• Jirgin kankara na Greenland yana narkewa da sauri fiye da kowane lokaci, Jami'ar Bristol
• Asarar Kankara ta Greenland: Jan. 2004 - Yuni 2014 (animation NASA)
• Greenland Ice Cap, Rahoton 1942-1944 a Makarantar Kolejin Dartmouth
• Binciken Adabi na Greenland Ice Cap 1953 a Laburaren Kwalejin Dartmouth