Evidence for a palaeo-subglacial lake on the Antarctic continental shelf.
Evidence for a palaeo-subglacial lake on the Antarctic continental shelf.
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DOI：
10.1038/ncomms15591
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发表时间：
2017-06-01
影响因子：
16.6
通讯作者：
Mogollón JM
中科院分区：
文献类型：
--
作者：
Kuhn G;Hillenbrand CD;Kasten S;Smith JA;Nitsche FO;Frederichs T;Wiers S;Ehrmann W;Klages JP;Mogollón JM
冰下湖泊广泛分布在南极冰盖之下，但它们对冰盖动态的控制以及它们藏匿生命的能力仍然没有得到很好的描述。在这里，我们提出了南极大陆架上有一个古冰下湖泊的证据。从松岛湾的基岩盆地中发现的明显的沉积相表明，沉积在低能量的湖泊环境中。扩散-平流模拟表明，相应沉积物的孔隙水中的低氯浓度只能通过淡水环境中这一相的初始沉积来解释。这些观察表明，一个活跃的冰下融水网络，类似于在现存冰盖下观察到的网络，在最后一次冰川时期也是活跃的。它还为完善对这些独特环境的探索提供了一个新的框架。虽然在现代南极冰盖下发现了许多冰下湖泊，但对它们在过去冰川中的盛行程度知之甚少。在这里，库恩等人。目前的沉积学证据表明，在最后一次冰期期间，松岛湾有一个活跃的古冰下湖泊。
Subglacial lakes are widespread beneath the Antarctic Ice Sheet but their control on ice-sheet dynamics and their ability to harbour life remain poorly characterized. Here we present evidence for a palaeo-subglacial lake on the Antarctic continental shelf. A distinct sediment facies recovered from a bedrock basin in Pine Island Bay indicates deposition within a low-energy lake environment. Diffusive-advection modelling demonstrates that low chloride concentrations in the pore water of the corresponding sediments can only be explained by initial deposition of this facies in a freshwater setting. These observations indicate that an active subglacial meltwater network, similar to that observed beneath the extant ice sheet, was also active during the last glacial period. It also provides a new framework for refining the exploration of these unique environments. While a number of subglacial lakes have been discovered beneath the modern Antarctic ice sheet, little is known regarding their prevalence during past glaciations. Here, Kuhn et al. present sedimentological evidence for an active palaeo-subglacial lake in Pine Island Bay during the last glaciation.