タンザニアにあるアフリカ最高峰キリマンジャロ。頂上氷原にて行われた最近の調査で、その氷原が20年以内にすべて消え去ってしまう可能性が高いことがわかった。
キリマンジャロ：溶解が進み、孤立した氷塊 |
ジャーナル誌「the Proceedings of the National Academy of Science（PNAS）」に掲載されたその研究でわかったことは、1912年から2007年までにキリマンジャロを覆う氷原のうち８５％が消え去ったこと。そして、そのうちの２６％が2000年から溶解したということだ。
その氷床コアの調査では、11,700年前のものと思われる表層までさかのぼって行われた。キリマンジャロの氷原は現代まで溶解した形跡がなく、4,200年前に300年間続いたとされる干ばつにも耐えていた模様だ。
気温上昇による侵食が進んだ氷原 |
その氷床コアの調査では、11,700年前のものと思われる表層までさかのぼって行われた。キリマンジャロの氷原は現代まで溶解した形跡がなく、4,200年前に300年間続いたとされる干ばつにも耐えていた模様だ。
雲の減少による氷原表層面の気温上昇、降水量の変化がこの溶解をもたらした要因と考えられる。
この研究結果は劇的な気候変動を示す証拠となるだろう。
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