メッセンニアの塩分危機の後,地中海の壊滅的な洪水
D Garcia-Castellanos1, F Estrada, I Jiménez-Munt
1Institut de Ciències de la Terra Jaume Almera, CSIC, Solé i Sabarís s/n, Barcelona, Spain.
Nature
|December 17, 2009
まとめ
ザンクリアンの洪水は533万年前,地中海を急速に補充した. 新しい分析は,洪水によって形成されたジブラルタル海峡の運河を明らかにし,数ヶ月から2年間続く急速な充填イベントを示唆しています.
科学分野:
- 地質学 地質学 地質学
- 海洋学 海洋学 海洋学
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
背景:
- 地中海はメセニア塩分危機 (約5.6万年前) の間に乾燥した.
- Zanclean flood (~5.33 Ma) の洪水は,ジブラルタル海峡を通って盆地を急速に補充しました.
- 洪水の特性は,その急激さや進化も含め,未だに十分に理解されていない.
研究 の 目的:
- ジブラルタル海峡内の侵食的な特徴を調査する.
- 海峡を横断する切断された運河の形状と起源を決定する.
- Zancleanの洪水の持続時間と放出量を推定するために.
主な方法:
- ジブラルタル海峡横断の掘削孔と地震データの分析.
- 山川で検証された切断モデルの適用.
- 200キロメートルの運河の形質分析.
主要な成果:
- 切断された運河は,ジブラルタル海峡を横断して連続しています.
- 運河の形態は洪水による浸食と一致し,以前の河川浸食ではない.
- 推定ピーク放出量は ~10^8 m^3 s^-1で,切断率は >0.4 m/dayである.
- 数ヶ月から2年までの期間で移転した水の90%です.
結論:
- ザンクリアンの洪水は,非常に急激な出来事でした.
- 地中海における海面上昇のピークは,1日10mを超えました.
- この発見は,ザンクリアン洪水の動態と影響に関する私たちの理解を洗練します.
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