Aix Marseille Université, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, Collège de France, 13545 Aix-en-Provence Cedex 04, France.
Proc Natl Acad Sci U S A. 2013 Apr 23;110(17):6682-7. doi: 10.1073/pnas.1214676110. Epub 2013 Apr 8.
Continental ice sheets are a key component of the Earth's climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate-lake-FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas.
大陆冰盖是地球气候系统的关键组成部分，但它们的内部动态仍需要进一步研究。自上一次冰消期以来，北欧亚大陆的芬兰-斯堪的纳维亚冰盖（FIS）一直与黑海（BS）流域相连，使这个流域成为研究前冰盖动态的理想地点。在这里，我们从 BS 中提取的岩芯中，结合使用钕同位素、高分辨率元素分析和生物标志物来追踪沉积物物源和河流径流量的变化。我们揭示了源自迪斯纳湖的融水的周期性释放，迪斯纳湖是与 Heinrich 盛冰期 1 期间的 FIS 相关的一个前冰川湖。气候-湖泊-冰盖系统内的区域相互作用，与亚冰下水的可利用性变化有关，导致 FIS 突然排入 BS 流域的排水循环。这种现象使 BS 的水位上升了约 100 米，直到博斯普鲁斯海峡的浅滩被淹没，淹没了 BS 广阔的西北大陆架，并深深地影响了 BS 的水文学和循环，可能还影响了马尔马拉海和爱琴海。
