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Yanayin Dutsen Kenya

Daga Wikipedia, Insakulofidiya ta kyauta.
Dutsen Kenya wani dutse ne mai fitattun wuta wanda ya tashi da kimanin shekaru miliyan 3 da suka gabata kuma ya fashe da kimanin shekaru 2.6 da suka gabata.

yanayi dutse Yanayin Dutsen Kenya ya taka muhimmiyar rawa wajen haɓaka tsaunin, yana tasiri yanayin yanayin ƙasa da muhalli a tsakanin sauran abubuwa.  Yankin da ke kusa da Dutsen Kenya yana rufe da adadi mai yawa na bayanan tashar yanayi mai tsayi tare da jerin ma'auni masu tsayi don haka yanayin yana da kyau sosai.]  Yana da yanayi na tsaunuka na equatorial na yau da kullun wanda Hedberg ya bayyana a matsayin hunturu kowane dare da bazara kowace rana[1]

Shekarar ta kasu kashi biyu daban-daban na rigar yanayi da kuma daban-daban biyu na bushewa wanda ke nuna lokacin rigar da bushewa a cikin ƙasashen Kenya. Kamar yadda Dutsen Kenya ya kasance a tsawo daga mita 1,374 (4,508 zuwa mita 5,199 (17,057 yanayin ya bambanta sosai a kan dutsen kuma yana da yankuna daban-daban na tasiri. Ƙananan, tuddai na kudu maso gabas sune mafi ruwan sama kamar yadda tsarin yanayi ya fito ne daga Tekun Indiya. Wannan yana haifar da gandun daji mai yawa a kan waɗannan gangaren. A saman dutsen mafi yawan ruwan sama ya faɗi a matsayin dusar ƙanƙara, amma mafi mahimmancin tushen ruwa shine sanyi. Haɗe, waɗannan suna ciyar da kankara 11.

Yanayin yanayi na yanzu

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Yanayin da ke kan Dutsen Kenya yana da ruwa, amma ya bushe fiye da yadda ya kasance a baya. Yanayin zafi ya kai iyaka, wanda ke raguwa tare da tsawo. A cikin ƙananan yankin alpine yawanci ba sa zuwa ƙasa da 12 °C (54 °F) ° C (54 ° F). [2] Snow da ruwan sama sun zama ruwan dare daga Maris zuwa Disamba, amma musamman a cikin lokutan rigar guda biyu. Lokacin rigar da aka haɗu ya kai 5/6 na ruwan sama na shekara-shekara. Monsoon, wanda ke sarrafa lokutan rigar da bushewa, yana nufin cewa mafi yawan shekara akwai iskõki na kudu maso gabas, amma a lokacin Janairu da Fabrairu babbar hanyar iska ita ce arewa maso gabas.

Lokaci

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A watan Janairu yankin Intertropical Convergence Zone (ITCZ) yana cikin kudancin kudancin Tekun Indiya. A watan Yulin yana kan iyakar arewacin Tibet da Arabiya. Yayin da yake canzawa, Dutsen Kenya yana fuskantar lokacin rigar.

Dutsen Kenya, kamar yawancin wurare a cikin wurare masu zafi, yana da lokutan rigar biyu da lokutan bushewa biyu sakamakon ruwan sama. Daga tsakiyar Maris zuwa Yuni lokacin ruwan sama mai yawa, wanda aka sani da ruwan sama mai tsawo, yana kawo kusan rabin ruwan sama na shekara-shekara a kan dutsen. Wannan ya biyo bayan rigar yanayi biyu na fari wanda ke ci gaba har zuwa Satumba. Oktoba zuwa Disamba shine gajeren ruwan sama lokacin da dutsen ke karɓar kusan kashi ɗaya bisa uku na ruwan sama. A ƙarshe daga Disamba zuwa tsakiyar Maris shine lokacin bushewa, lokacin bushewa lokacin da dutsen ke fuskantar ruwan sama mafi ƙanƙanta.

Dutsen Kenya yana kan ma'auni. Wannan yana nufin a lokacin rani na arewacin rana tana arewacin dutsen. Tsayi da kuma bangaren ruwa da manyan tsaunuka suna haifar da arewacin dutsen da ke saman a yanayin bazara. A lokaci guda, gefen kudu yana fuskantar yanayin hunturu. Da zarar lokacin rani ne na kudancin, yanayin ya juya.

Hadley Cell yana sarrafa Yankin Haɗuwa na Intertropical wanda a cikin Tekun Indiya ana kiransa MonsoonRuwan sama

Ƙananan belin matsin lamba a kusa da ma'auni da aka sani da Yankin Intertropical Convergence (ITCZ) yana da alhakin lokutan rigar da bushewa na Dutsen Kenya.[3] A lokacin lokutan fari biyu ITCZ yana kan Arabiya a watan Yuli da kudancin Tanzania da arewacin Zambia a watan Maris. Yankin matsin lamba yana wucewa a kan Kenya yayin da yake musayar tsakanin iyakarsa biyu da Dutsen Kenya, da Kenya, suna fuskantar lokutan rigar. Adadin ruwan sama yana canzawa daga shekara zuwa shekara kuma ya dogara da Yanayin zafi na teku a cikin Tekun Atlantic da Tekun Indiya da El Niño da sauran dalilai.[4] Tekuna masu zafi da El Niño dukansu suna haifar da inganta ruwan sama.[5]

A kowane lokaci na shekara sai dai a kusa da Janairu, matsin lamba da ke kan Tibet yana fitar da iskõki a cikin siffar doki daga Tekun Indiya, a gabashin Afirka sannan zuwa Indiya. Wannan yana haifar da iska mai yawa ta kudu maso gabas a Dutsen Kenya. A kusa da Janairu akasin haka gaskiya ne kuma Dutsen Kenya yana da iskõki na arewa maso gabas.[4]

Dutsen ya tashi sosai daga kimanin mita 1,400 (4,600 zuwa mita 5,199 (17,057 don haka babban cikas ne ga iskõki masu yawa. A lokacin rigar, ruwan sama daga Tekun Indiya yana kawo iska mai laushi zuwa dutsen. Wannan iska tana da tsayayya kuma sau da yawa tana da hazo. Yawancin lokaci ana karkatar da shi a gefen dutsen maimakon wucewa, musamman Yuni zuwa Oktoba. A wasu lokuta na shekara, ana iya tilasta iska zuwa dutsen wanda ke haifar da ruwan sama. A wannan yanayin tsawa mai tsanani na iya faruwa.[6]

Tsarin yau da kullun

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A lokacin fari dutsen kusan koyaushe yana bin yanayin yau da kullun. Babban canjin zafin jiki na yau da kullun yana faruwa wanda ya sa Hedberg ya yi ihu da hunturu kowace dare da rani kowace rana..[1] Akwai bambanci a cikin mafi ƙaranci da matsakaicin yanayin zafi kowace rana, amma daidaitattun canji na matsakaicin sa'a yana da ƙananan.

A lokacin fari, safiya yawanci yana da haske da sanyi, amma dutsen yana ɓoye a cikin girgije da tsakar rana.

Rana ta yau da kullun tana da haske da sanyi da safe tare da karancin zafi. Dutsen yana cikin hasken rana kai tsaye wanda ke haifar da yanayin zafi ya danshi da sauri tare da yanayin zafi mafi zafi da ke faruwa tsakanin karfe 9 na safe da tsakar rana. Wannan ya dace da matsakaicin matsin lamba, yawanci a kusa da 10am. Ƙananan a kan dutsen, tsakanin mita 2,400 (7,900 da mita 3,000 (9,800 , girgije sun fara samuwa a kan yankin gandun daji na yamma, saboda iska mai laushi daga Tafkin Victoria.[7] Iska mai iska da iska mai zafi ta haifar a hankali tana kawo waɗannan girgije zuwa yankin taron da rana. A kusa da karfe 3 na yamma akwai mafi ƙarancin hasken rana da matsakaicin zafi wanda ke haifar da ainihin zafin jiki da aka fahimta ya sauka. A karfe 4 na yamma akwai mafi ƙarancin matsin lamba. Wannan girgije na yau da kullun yana kare kankara a kudu maso yammacin dutsen wanda in ba haka ba zai sami rana kai tsaye kowace rana, yana inganta narkewar su. Girgizar da ke tashi a ƙarshe ta kai ga busassun iska na gabas kuma ta ɓace, wanda ke haifar da sararin sama mai haske da karfe 5 na yamma. Akwai wani matsakaicin zafin jiki da ke da alaƙa da wannan.

Kasancewa dutse ne na equatorial sa'o'in hasken rana ba su da yawa tare da sa'o-i goma sha biyu. Rana ta fito kusan 0530 tare da faɗuwar rana a 1730. A cikin shekara akwai bambancin minti daya tsakanin gajerun kwanaki da mafi tsawo.[8] Da dare, sararin sama yawanci yana da haske tare da iskõki na Katabatic da ke hurawa a cikin kwarin. Sama da ƙananan yankin alpine yawanci akwai sanyi kowace dare.[2]

Yanayin zafi

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Yanayin zafi a Dutsen Kenya yana canzawa sosai. Wannan canjin ya fi girma a kan ƙananan gangaren yankin moorland. A tsawo na mita 3,000 (9,800 akwai matsakaicin 11.5 ° C a cikin zafin jiki na yau da kullun, wannan ya sauka zuwa 7.5 ° C na mita 4,200 (13,800 da 4 ° C a mita 4,800 (15,700 . Canjin zafin jiki na rana yana raguwa tare da tsawo, don haka ƙimar raguwa tana raguwa yayin rana. Wannan tasirin yana nufin raguwar rana a Dutsen Kenya ya fi matsakaici ga iska mai bushe. Da daddare yawan raguwa ya sake zama ƙasa da matsakaici don iska mai bushe saboda iskar Katabatic daga kankara. Canjin zafin jiki ba shi da yawa a lokacin rigar yayin da girgije ke aiki a matsayin mai sanyaya.   

Bambance-bambancen yanayin zafi yana da alaƙa kusa da hasken rana kai tsaye.  Rana ta yi sauri ta dumama ƙasa da 'yan digiri, wanda hakan ke sa iskar da ke kusa da ƙasa dumi.  Wannan iskar tana yin sanyi don isa ga daidaito tare da matsakaicin zafin iska da sauri lokacin da sararin sama ya mamaye.  Layer na iska tsakanin rabin mita na ƙasa a cikin kwaruruka kuma yana nuna yanayin zafi daban-daban da daddare zuwa saman samansa.  A cikin darare masu haske na lokacin rani, ƙasa tana yin sanyi da sauri tana sanyaya iska kusa da ita.  Wannan yana haifar da iskar katabatic daga raƙuman ruwa zuwa cikin kwaruruka wanda ke haifar da gindin kwarin ya yi sanyi fiye da manyan tudu da ke gefensu.  Baker ya gano cewa kwarin Teleki yana yawan sanyi 2°C da daddare fiye da tsaunin da ke kewaye.[2]  Wannan ya tilasta wa tsire-tsire irin su senecios da lobelias tsayi don guje wa daskarewa masu mahimmanci, saboda daskarewa yana da haɗari ga tsire-tsire.[2] 

Ruwan sama

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Matsakaicin ruwan sama a kan dutsen yana faruwa a tsakiyar Maris zuwa Yuni lokacin rigar, amma matakin ruwan sama na iya bambanta sosai daga shekara zuwa shekara. A lokacin rigar ana rufe shi kusan a kai a kai. Rabin ruwan sama na shekara-shekara yana kan ruwan sama mai tsawo Maris zuwa Yuni, tare da kashi ɗaya bisa uku na jimlar a cikin watan Oktoba zuwa Disamba gajeren ruwan sama. A cikin lokutan rigar da bushewa wuri mafi ruwan sama a kan dutsen shine gangaren kudu maso gabas.[9][10] Matsakaicin kudu maso gabas shine saboda jagorancin iskõki masu yawa. Matsakaicin a yamma yafi saboda tasirin rana lokacin da sararin sama ya bayyana, saboda iska mai iska a cikin kwari da ke kawo girgije a kan dutsen da yamma. Ba tare da wannan tasirin ba za a sa ran wannan yanki ya kasance a cikin inuwa ruwan sama.[6]

Sama da mita 4,500 (14,800 mafi yawan hazo ya faɗi a matsayin dusar ƙanƙara, [11] amma kamar yadda iska ta bushe sosai babu yawancin wannan. Sabili da haka, babban tushen ruwa a cikin yankunan alpine da nival shine sanyi na dare.[2] Wannan yana taka muhimmiyar rawa wajen ciyar da kankara, duk da haka har yanzu babu wata hanyar da za a auna gudummawar da wannan ke bayarwa. Raguwa ƙasa, a lokacin fari, raɓa kowace safiya tana da irin wannan rawar, kuma an kiyasta cewa yawancin ƙananan rafi ana ciyar da su ta wannan hanyar.[9]

Yanayin da ya gabata

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Ana fassara yanayin da ya gabata ta amfani da hanyoyi da yawa ciki har da matakan tafkin, ƙarfin kogi, tsarin dunƙule, girman glacial da pollen.[12] Yayin da mutum ya koma baya, sakonnin da aka yi amfani da su sun zama masu faɗi. Duk da yake ana iya ƙaddamar da yanayin don takamaiman wuri shekaru 20,000 da suka gabata, [13] shekaru miliyan 5 da suka gabata dole ne a yi la'akari da yanayin a mafi yawan Afirka kuma a daidaita sakamakon ta amfani da kwatankwacin yanzu. Matsalolin da ke tattare da komawa baya na dogon lokaci sun haɗa da rarraba rubuce-rubuce da ƙarancin burbushin ciyayi saboda yanayin da ba shi da kyau.[12]

A tsawon lokaci, ƙasa yana sarrafawa ta hanyar Milankovitch cycles canza adadin Hasken rana da ke kaiwa duniya. Rashin ƙarfi da ƙarfafawar ruwan sama yana taka muhimmiyar rawa. Siroco et al. sun ba da shawarar cewa ƙarfin ruwan sama yana da alaƙa da albedo a cikin Himalaya. Yanayin sanyi a arewacin hunturu yana haifar da karin hasken rana da aka nuna daga dusar ƙanƙara da kankara da kuma raunin ruwan sama na rani, wanda ke haifar da yanayin bushe a Gabashin Afirka.[14] Ƙarfin ruwan sama kuma yana da alaƙa da sake zagayowar Milankovitch tare da jinkirin kusan shekaru 8,000. Gabaɗaya matsakaicin ruwan sama yana faruwa shekaru 2,500 bayan mafi ƙarancin glacial. Wannan matsakaicin ya dace da mafi ƙarancin yanayin zafi na teku.[15]

Tun farkon lokacin Quaternary arewacin arewacin ya sha wahala 21 manyan shekarun kankara kuma wannan siginar tana nan a Gabashin Afirka.[12] Yanayin da ya gabata na Kenya ya nuna siginar yanayi a Turai, shiga da barin yanayin sanyi a lokaci guda. A lokacin mafi girman glacial na ƙarshe, shekaru 20,000 da suka gabata, Ice Sheet na Turai zai karkatar da tsarin yanayi na Atlantic a kan Kenya. Wannan zai haifar da Kenya da irin wannan yanayi kamar na yau da kullum a Turai.[16] A cikin shekaru 6,000 da suka gabata Dutsen Kenya yana da jerin akalla ƙananan ci gaba guda shida, tare da matsakaicin ƙarshe a ƙarshen ƙaramin zamanin kankara a cikin 1900.[17]

Kasancewar yanayin gabashin Afirka ya fi sanyi gabaɗaya ana iya ganinsa ta kallon sauran tsaunuka kamar Mlunt Kilimanjaro, Dutsen Ruwenzori da Dutsen Elgon.  Dukkansu keɓaɓɓun aljihu ne na yanayin yanayin tsaunuka masu kama da fauna da flora iri ɗaya.  Wannan yana nufin cewa lallai wannan muhallin ya kasance ya yadu a ƙananan tsaunuka domin ya isa dukan waɗannan tsaunuka.  Har yanzu dole ne a sami aljihu na yanayin yanayin ƙasa na yanzu da ke rayuwa don in ba haka ba dabbobin da ke cikin waɗannan tsarin za su shuɗe.]  Wani bayani na dabam shine idan aka yi la'akari da yanayin miliyoyin shekaru, yuwuwar guguwa ta jigilar flora da fauna tsakanin tsaunuka yana da girma.

Dutsen Kenya.jpg

Dutsen Kenya dutsen wuta ne mai aiki a cikin Pliocene, shekaru miliyan 2.5-5 da suka gabata (mya). 5 mya Tekun Bahar Rum ya bushe kuma dunes na Sahara sun fi kudu; yankin da yanzu Kenya ya kasance busasshiyar Savanna.[18] A lokacin 3.7 mya yanayin ya fi ruwan sama fiye da yadda yake a halin yanzu, kuma an kafa tsarin tsire-tsire a Gabashin Afirka, kodayake har yanzu akwai bambancin da yawa a cikin nau'o'in da rarraba tsawo saboda yanayin yanayi. 2.5 mya na farko na manyan shekarun kankara 21 a arewacin arewacin lokacin Quaternary ya faru. Yankin Afirka mai zafi ya sami yanayin sanyi fiye da yadda yake a yanzu.[12] An saukar da belin ciyayi na Habashawa kuma irin wannan siginar za ta kasance a Kenya.[19] Lokaci mai bushewa 1 mya ya zama mafi bayyane, yanayin da ke ci gaba a yau.[12]

150 kya shine matsakaicin babban glaciation na ƙarshe, wanda shine mafi girma daga cikin glaciations na Pleistocene. Wannan ya biyo bayan mai laushi na Eemian interglacial lokacin da yanayin zafi ya fi na yanzu.[20] Wani lokaci mai bushewa ya biyo baya, wanda ya kasance daga 100 zuwa 90 kya tare da dunes da ke ginawa a Kudancin Afirka, [21] sannan ya biyo bayan ɗan gajeren lokaci amma mai tsanani daga 75 zuwa 58 kya. Kusan ƙarshen wannan lokacin sanyi taron Heinrich na farko (H6) ya faru, ya saki tarin kankara zuwa arewacin Atlantic 66 kya.[22] Wannan ya haifar da yanayin sanyi a arewacin arewa da kuma Himalaya mai sanyi wanda mai yiwuwa ya haifar da raunanawar ruwan sama.[20][21] Jerin abubuwan Heinrich sun biyo baya, tare da bushewar yanayin Gabashin Afirka a 50, 35, 30, 24, 16 kuma ya ƙare tare da lokacin Younger Dryas 12kya.

31-21 kya wani lokaci ne mai sanyi, tare da belin ciyayi da ke raguwa. Nau'in gandun daji na sama sun faru ne inda a halin yanzu ƙananan nau'in gandunar daji suke kuma akwai shaidar cewa gandun daji ya yadu a ƙananan tsaunuka.[12] Rubuce-rubucen daga Kongo sun yarda da wannan amma Lowe da Walker sun ba da shawarar cewa Gabashin Afirka ya fi na yanzu. Wannan bambancin na iya bayyanawa ta hanyar bambancin wuri don matsaloli tare da daidaita kwanakin.[22]

Last Glacial Maximum (LGM) ya faru ne 23-14.5 kya tare da wani lokaci mai bushewa a Afirka lokacin da hamada ta kai daruruwan kilomita (miles) zuwa kudu fiye da yanzu.[23] Yanayin zafi ya kasance 5-6 °C sanyi fiye da yanzu kuma akwai janyewar gandun daji.[12][13] Lokacin bazara a lokacin LGM ya kasance mai rauni sosai.[24] Glacial moraines daga kusa da ƙarshen LGM a Gabashin Afirka ya nuna cewa ruwan sama na kudu maso gabas bai yi rigar ba a lokacin LGM fiye da ruwan sama na arewa maso gabas na yanzu. Girgije na Stratus na iya kasancewa mai yawa wanda ya haifar da sakamako mai sanyaya amma ruwan sama kadan.[12] 

Da 13.8 kya yanayin ya yi danshi kuma gandun daji na tsaunuka ya sake yaduwa bayan mafi ƙaranci a lokacin LGM.[22] Ruwan sama ya sake ƙarfafawa, kuma matakan tafkin da ayyukan kogi a Gabashin Afirka sun karu.[24][12][22] Tsire-tsire masu tsawo sun fi iyakance ta yanayin zafi kuma ba fari ba, kuma yana nuna yanayin rigar.[24]

Kafin Younger Dryas yanayin zafi yayi kama da na yanzu amma gandun daji bai cika ba. A lokacin ƙaramin Dryas 12.9-11.5 kya da taron Heinrich na ƙarshe ya kawo, an sami raguwar ruwan sama na rani a Gabashin Afirka, [24] kuma gandun daji ya koma baya kuma matakan tafkin Gabashin Afirka sun faɗi. [22] dazuzzuka sun kai iri ɗaya da yawa kamar yadda suke a yau bayan ƙaramin Dryas lokacin da yanayin ya sake zama mai laushi.[22]

Shekaru dubu 5 masu zuwa, daga 10-5 kya, yanayin ya fi na yanzu amma har yanzu akwai oscillations.[12][23] Ruwan sama ya kasance mai ƙarfi, amma akwai ƙarni da yawa da suka raunana.[25] haya zuwa wani lokaci mai bushe, amma yanayin har yanzu yana da danshi fiye da yanzu.[22]

Bayan 5 kya ruwan sama ya fara raunana a hankali [25] kuma yanayin Gabashin Afirka ya zama kama da na yanzu, amma dan kadan ya fi sanyi kuma ya bushe. [22] Matsayin tafkin a Habasha sun kasance ƙasa daga 5.4 zuwa 2.5 kya da kuma a Ghana 4.5-3.2 kya.[26] A cikin waɗannan shekaru dubu biyar da suka gabata, Dutsen Kenya ya shiga cikin jerin ƙananan ci gaban kankara. Akwai mafi ƙarancin zafin jiki sama da 3.7-2.5 kya kuma a lokacin ƙaramin zamanin kankara wanda ya kai shekarun 1300-1900 lokacin da mulkin permafrost ya mamaye Dutsen Kenya.[17]

Dutsen Kenya an rufe shi da kankara, wanda ya rushe dutsen don fallasa matattarar dutsen da ke samar da taron na yanzu.[27] Wannan zai haifar da yanayi mai sanyi da kuma gaskiyar cewa dutsen ya kai tsawo tsakanin mita 5,000 (16,404 -6,500 mita (21,300 wanda ya haifar da yanayin sanyi.[27] Tun daga wannan lokacin dutsen ya sha wahala da yawa na kankara, amma kawai kwanan nan ne za a iya cika shi a cikin lokaci saboda kowane sabon kankara da ke lalata moraines na waɗanda suka gabata, idan kankara ta ci gaba a kansu.

Glaciations a Gabashin Afirka suna da alaƙa da yanayin sanyi, bushewa lokacin da ruwan sama bai yi yawa ba, amma ƙarin raguwar zafin jiki yana nufin duk wani hazo mai ƙarfi ya kasance. Stratus girgije, wanda mai yiwuwa ya mamaye a lokacin wasu daga cikin glaciations zai samar da rufi amma kadan hazo.[12]

Akwai ƙananan ci gaban ƙanƙara da aka rubuta a kan dutsen a cikin shekaru 6,000 da suka gabata. Na farko daga cikin wadannan ya faru ne tsakanin 6950 da 4500 kya lokacin da aka sami babban ci gaba a cikin kwarin Teleki.[28] Wani moraine a cikin kwarin Hobley ya kasance dan kadan kafin wannan. 5.7 kya da Cesar da Josef glaciers sun janye daga Hausberg Tarn a karo na karshe. An yi amfani da wannan tarn don ƙaddamar da yanayin da ya gabata ta hanyar kallon rikodin laka.[17]

Jerin koma baya da ci gaba sun biyo baya, tare da mafi girman glacial a: 5700, 4900, 4700, tsakanin 4300 da 4200, 4000, 3100, 2800, 1900, 1200, 600, 400 da 50 ya. (Lura da sikelin shekara da ta gabata yana ɗaukar 1950 zuwa shekara 0.) Gilashin da suka wanzu tsakanin 2.8 da 2.3 kya za su kasance sanyi ne saboda yanayin sanyi a lokacin kuma don haka sun daskare zuwa gado sabili da haka ba su lalace ba.[17] A cikin 1900, lokacin da Mackinder ya ziyarci dutsen, kankara sun kasance kusa da ƙananan ƙanƙara.[29]

Wadannan ci gaban kankara suna da alaƙa da mafi ƙanƙanta a matakin Tafkin Turkana a kusa da 4800, 4200, 3700, 3500, 3000, 2500, 2500, 2000 da 1600-1400 ya.[26] Kamar yadda glaciers za su ci gaba a lokacin bushewar lokacin da zafin jiki ya fi sanyi, ba a san dalilin da ya sa daidaituwa ba ta fi kyau ba, amma yana iya zama saboda rashin daidaito a cikin soyayya.[17]

Tun daga shekara ta 1900 kankara suna ci gaba da janyewa kuma bakwai daga cikin 18 sun ɓace.

Palaeobotany

[gyara sashe | gyara masomin]

Palaeobotany ya Palaeobotany ya dogara ne da gaskiyar cewa kowane yanayi yana da wasu tsire-tsire, wanda kuma yana aiki a matsayin wakili na sauyin yanayi ta hanyar sanin wuraren zama na zamani da suke faruwa a ciki. Tushen tafkin da aka ɗauka daga Tafkin Tsarkaka a mita 2,400 (7,900 ft) akan dutse, yana gano ɗumamar yanayi ta hanyar nazarin pollen da aka samu a cikin ainihin.  Za a iya daidaita zurfin tushen tare da shekaru ta hanyar amfani da fasahar saduwa da carbon-14 da ke ɗaukan adadin lalata.  Tsayin Tafkin Tsarkaka mai tsawon mita 13.4 (44 ft) an kiyasta zai koma shekaru 18,600.  Jigon yana nuna tsalle-tsalle na samfuran pollen a cikin shekaru 11,000, daidai da filin wasa na Younger Dryas a Turai.  A wannan lokacin da Afirka redwood, Hagenia, pollen ya bayyana.  Wannan bishiyar tana da alaƙa ta kusa da gefen saman gandun daji na Afro-timberline.  Kafin wannan ciyayi na moorland da nau'in zafi sun mamaye ainihin.  Bayan gabatar da Hagenia, wasu nau'in bishiyar sun fara bayyana har sai da tafkin ya kasance a cikin dajin Montane shekaru 5,000 kafin yanzu.  Wannan yayi daidai da ɗumamar 8 °C tun farkon ainihin.  Shekaru 18,000 da suka wuce tafkin yana cikin wurin zama a yanzu yana kan mita 3,400 (11,200 ft) akan Dutsen Kenya, mita 1,000 (3,300 ft) sama da tafkin  Wani muhimmin batu shi ne cewa wannan bincike ya shafi wani wuri ne kawai a kan dutsen. Wannan aikin ya nuna cewa sauyin yanayi na Kenya yana faruwa a lokaci guda da na Turai.

Wani bayani na daban game da canjin pollen shine cewa yanayin ya zama mai laushi, amma yanayin zafi bai canza sosai kamar yadda aka ba da shawarar ba.

Manazarta

[gyara sashe | gyara masomin]
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