Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung (AWI), P.O. Box 12 01 61, Bremerhaven, 27515, Germany.
Institute for Marine and Atmospheric Research Utrecht (IMAU) and Faculty of Geosciences, Department of Physical Geography, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, The Netherlands.
Nat Commun. 2020 Oct 12;11(1):5124. doi: 10.1038/s41467-020-18897-5.
Glacial/interglacial dynamics during the Quaternary were suggested to be mainly driven by obliquity (41-kyr periodicity), including irregularities during the last 1 Myr that resulted in on average 100-kyr cycles. Here, we investigate this so-called Mid-Pleistocene Transition via model-based deconvolution of benthic δO, redefining interglacials by lack of substantial northern hemispheric land ice outside of Greenland. We find that in 67%, 88% and 52% of the obliquity cycles during the early, middle and late Quaternary, respectively, a glacial termination is realized leading to irregular appearances of new interglacials during various parts of the last 2.6 Myr. This finding suggests that the proposed idea of terminations leading to new interglacials in the Quaternary as obliquity driven with growing influence of land ice volume on the timing of deglaciations during the last 1 Myr might be too simple. Alternatively, the land ice-based definition of interglacials needs revision if applied to the entire Quaternary.
在第四纪，冰川/间冰期的动态主要由轨道偏心率（41000 年的周期）驱动，包括在过去 100 万年中出现的不规则变化，导致平均出现 10 万年的周期。在这里，我们通过基于模型的海底δO 反卷积来研究这种所谓的中更新世转变，通过缺乏格陵兰以外的大量北半球陆地冰来重新定义间冰期。我们发现，在第四纪早期、中期和晚期的 67%、88%和 52%的轨道偏心率周期中，分别实现了冰川结束，导致在过去 260 万年的不同时期出现新的间冰期。这一发现表明，在第四纪，提出的以轨道偏心率驱动的终止导致新的间冰期的想法，以及陆地冰体积对末次冰消期时间的影响越来越大，可能过于简单。或者，如果将其应用于整个第四纪，基于陆地冰的间冰期定义需要修改。
