Ohneiser Christian, Beltran Catherine, Bollen Michael, Fougere Dannielle, Egli Ramon
Department of Geology, University of Otago, Dunedin, New Zealand.
Department of Geology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Vienna, Austria.
Nat Commun. 2025 Apr 3;16(1):3175. doi: 10.1038/s41467-025-58302-7.
We present an environmental magnetic record from a 6.1 metre sediment core from Lake Hayes, Te Waipounamu, South Island, New Zealand that spans the last c. 16.5 kyr and contains a logical progression of climate events. Periods of anoxia are identified from greigite that formed during reducing conditions whereas magnetite-dominated intervals indicate an oxygenated, well mixed water column. Before c. 15.5 ka, magnetite was eroded from schist and transported to the lake by glaciers. During the Antarctic Cold Reversal (between c. 14.7-13.0 ka), redox oscillations were modulated by the long term Interdecadal Pacific Oscillation (IPO) control on precipitation and wind strength. Later, during the Younger Dryas (c. 12.9-11.7 ka), the lake became anoxic suggesting less rain and wind and persistent drought conditions. In this region, the Younger Dryas was warmer than today which may indicate persistent drought conditions may return as the climate warms, in contradiction to projections from numerical climate models.
我们展示了来自新西兰南岛蒂怀波纳穆的海斯湖一个6.1米长沉积岩芯的环境磁记录，该记录跨越了过去约16.5千年，包含了一系列符合逻辑的气候事件。在还原条件下形成的硫复铁矿确定了缺氧期，而以磁铁矿为主的间隔表明水柱处于氧化且混合良好的状态。在约15.5千年前，磁铁矿从片岩中侵蚀出来，由冰川输送到湖中。在南极冷逆转期间（约14.7 - 13.0千年前），氧化还原振荡受长期年代际太平洋涛动（IPO）对降水和风强度的控制所调节。后来，在新仙女木期（约12.9 - 11.7千年前），湖泊变得缺氧，这表明降雨和风力减少以及持续干旱的状况。在该地区，新仙女木期比现在温暖，这可能表明随着气候变暖，持续干旱状况可能会重现，这与数值气候模型的预测相悖。
