Lokacin zafi na Afirka
 Lokacin zafi na Afirka | |
|---|---|
archaeological period (en)  | |
| Bayanai | |
| Gajeren suna | AHP |
| Nahiya | Afirka |
| Lokacin farawa | 14 millennium "BCE" |
| Lokacin gamawa | 35 century "BCE" |
| Zangon lokaci | Holocene |
Lokacin zafi na Afirka (AHP; wanda aka fi sani da wasu sunaye) lokaci ne na yanayi a Afirka a lokacin ƙarshen Pleistocene da Holocene, lokacin da arewacin Afirka ya fi ruwa fiye da yau. Rufe yawancin hamadar Sahara da ciyawa, bishiyoyi da tabkuna ya haifar da canje-canje a cikin karkatawar duniya, canje-canje na ciyayi da ƙura a cikin Sahara wanda ya ƙarfafa Ruwan sama na Afirka, da kuma karuwar iskar gas. A lokacin Last Glacial Maximum da ya gabata, Sahara ya ƙunshi filayen Dune masu yawa kuma galibi ba a zaune ba. Ya fi girma fiye da yau, kuma tabkuna da koguna kamar Lake Victoria da White Nile sun bushe ko kuma a ƙananan matakan. Lokacin zafi ya fara kimanin shekaru 14,600-14,500 da suka gabata a ƙarshen taron Heinrich 1, a lokaci guda zuwa dumama Bølling-Allerød. Koguna da tabkuna kamar Tafkin Chadi sun samo asali ko fadada, kankara sun girma a Dutsen Kilimanjaro kuma Sahara ta koma baya. Manyan sauye-sauye biyu na bushewa sun faru; a lokacin Younger Dryas da gajeren taron kiloyear 8.2. Lokacin zafi na Afirka ya ƙare shekaru 6,000-5,000 da suka gabata a Lokacin yanayi na Piora Oscillation. Duk da yake wasu shaidu suna nuna ƙarshen shekaru 5,500 da suka gabata, a cikin Sahel, Arabiya da Gabashin Afirka, ƙarshen lokacin ya bayyana ya faru a matakai da yawa, kamar taron kilo 4.2.
AHP ta haifar da yaduwar zama a cikin Sahara da hamadar Larabawa, kuma tana da tasiri sosai ga al'adun Afirka, kamar haihuwar wayewar Masar ta Dā. Mutanen da ke cikin Sahara sun rayu a matsayin mafarauta da masu tarawa da shanu, awaki da tumaki. Sun bar wuraren tarihi da kayan tarihi kamar ɗaya daga cikin tsofaffin jiragen ruwa a duniya, da zane-zanen dutse kamar waɗanda ke cikin kogon masu iyo da tsaunukan Acacus. An yi la'akari da lokutan zafi na farko a Afirka bayan gano waɗannan zane-zanen dutse a cikin ɓangarorin da ba a karɓa ba na yanzu na Sahara. Lokacin da lokacin ya ƙare, mutane a hankali sun watsar da hamada don tallafawa yankuna masu aminci na ruwa, kamar Kwarin Nilu da Mesopotamiya, inda suka haifar da al'ummomi masu rikitarwa na farko.
A cikin 1850 mai bincike Heinrich Barth ya tattauna yiwuwar canjin yanayi na baya wanda ya haifar da karuwar rigar a cikin Sahara bayan gano petroglyphs a cikin Murzuq Desert, kamar yadda Ahmed Hassanein ya yi bayan bincikensa na 1923 na hamadar Libya lokacin da ya ga hotunan dabbobin savanna a Gabal El Uweinat. Ƙarin binciken petroglyphs ya jagoranci mai binciken hamada László Almásy don ƙirƙirar manufar Green Sahara a cikin shekarun 1930. Daga baya a cikin karni na 20, an ƙara bayar da rahoton cewa Holocene ya nuna lokacin zafi a cikin Sahara.[1][2]
Ra'ayin cewa canje-canje a cikin yanayin duniya a kusa da Rana yana rinjayar ƙarfin ruwan sama ya riga ya ci gaba a 1921, kuma yayin da bayanin asali ya kasance wani ɓangare ba daidai ba, daga baya an sami shaidar da aka yadu don irin wannan sarrafawar yanayin a kan yanayi. Da farko an yi imanin cewa lokutan zafi a Afirka suna da alaƙa da matakan glacial ("ruwa ra'ayi") kafin kwanan wata na radiocarbon ya zama gama gari.[3] Da farko a cikin shekarun 1970s, an danganta zafi ga canje-canje na precession.[4]
Batutuwan bincike
[gyara sashe | gyara masomin]Duk da yake sauye-sauyen hazo tun lokacin da aka kammala zagaye na ƙarshe, girman da lokacin canje-canjen ba su da tabbas.[5] Dangane da yadda kuma inda ake yin ma'auni da sake ginawa, an ƙaddara kwanakin farawa daban-daban, kwanakin ƙarshe, tsawon lokaci da matakan hazo don lokacin zafi na Afirka. [1][6] Adadin hazo da aka sake ginawa daga bayanan paleoclimate kuma aka tsara ta hanyar ƙirar yanayi sau da yawa ba su dace da juna ba; gabaɗaya, ƙirar Green Sahara ana ɗaukarsa matsala ga samfuran tsarin ƙasa. [7][8] Akwai ƙarin shaidu game da ƙarshen AHP fiye da farkonsa.[9] Rushewar ruwan tafkin da Tasirin tafkin carbon ya sa ya zama da wahala a gano kwanan wata lokacin da suka bushe.[10] Canje-canje na shuke-shuke da kansu ba lallai bane su nuna canje-canje na hazo, kamar yadda canje-canje a cikin yanayi, nau'ikan nau'ikan shuke-tsire da canje-canje wajen Amfani da ƙasa suma suna taka rawa a cikin canje-canjen shuke-finai.[11] Isotope ratios kamar Hydrogen / deuterium rabo wanda aka yi amfani da shi don sake gina dabi'un hazo na baya kamar haka suna ƙarƙashin tasirin tasirin jiki daban-daban, wanda ke rikitar da fassarar su.[12] Yawancin rubuce-rubuce na Holocene a gabashin Afirka sun fito ne daga ƙananan tsaunuka.
Manazarta
[gyara sashe | gyara masomin]- ↑ 1.0 1.1 McCool 2019.
- ↑ Dawelbeit, Jaillard & Eisawi 2019.
- ↑ Wendorf, Karlén & Schild 2007.
- ↑ Reimer et al. 2010.
- ↑ Lézine, Duplessy & Cazet 2005.
- ↑ Junginger et al. 2014.
- ↑ Skinner & Poulsen 2016.
- ↑ Hopcroft et al. 2017.
- ↑ Knight, Merlo & Zerboni 2023.
- ↑ Menocal et al. 2000.
- ↑ Peck et al. 2015.
- ↑ Hoelzmann & Holmes 2017.