Long-term record of Barents Sea Ice Sheet advance to the shelf edge from a 140,000 year record
Long-term record of Barents Sea Ice Sheet advance to the shelf edge from a 140,000 year record
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巴伦支海冰盖的长期记录从 14 万年的记录推进到陆架边缘
DOI：
10.1016/j.quascirev.2016.08.014
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发表时间：
2016
影响因子：
4
通讯作者：
Pope E
中科院分区：
文献类型：
--
作者：
Pope E
自大约 20,000 年前的末次盛冰期以来，巴伦支海冰盖等海洋冰盖的全冰期范围和冰消期行为已有详细记录。然而，在第四纪陆架反复推进过程中，古老的海底沉积物和地貌的改造通常会掩盖它们的长期行为，从而妨碍我们的理解。在这里，我们利用熊岛槽口扇上的泥石流时间，提供了巴伦支海冰盖进展的第一份详细的长期记录。在过去 14 万年的四个不同时期，冰移动到了陆架边缘。迄今为止，最大的沉积物量是在 128,000 多年前最古老的推进过程中产生的。后来的进步发生在距今68,000年到60,000年、39,400年到36,000年以及26,000年到20,900年。泥石流表明，萨阿利亚冰盖和魏希瑟利亚巴伦支海冰盖的动力学有很大不同。魏克瑟利期期间反复出现的冰进退周期比萨利期的持续时间短。沉积物成分显示，两个冰期之间的冰盖结构也不同，这意味着萨阿利期期间供给熊岛冰流的冰主要来自斯堪的纳维亚半岛，而魏希瑟利期期间则从斯瓦尔巴群岛东部排出了更多的冰。
The full-glacial extent and deglacial behaviour of marine-based ice sheets, such as the Barents Sea Ice Sheet, is well documented since the Last Glacial Maximum about 20,000 years ago. However, reworking of older sea-floor sediments and landforms during repeated Quaternary advances across the shelf typically obscures their longer-term behaviour, which hampers our understanding. Here, we provide the first detailed long-term record of Barents Sea Ice Sheet advances, using the timing of debris-flows on the Bear Island Trough-Mouth Fan. Ice advanced to the shelf edge during four distinct periods over the last 140,000 years. By far the largest sediment volumes were delivered during the oldest advance more than 128,000 years ago. Later advances occurred from 68,000 to 60,000, 39,400 to 36,000 and 26,000 to 20,900 years before present. The debris-flows indicate that the dynamics of the Saalian and the Weichselian Barents Sea Ice Sheet were very different. The repeated ice advance and retreat cycles during the Weichselian were shorter lived than those seen in the Saalian. Sediment composition shows the configuration of the ice sheet was also different between the two glacial periods, implying that the ice feeding the Bear Island Ice stream came predominantly from Scandinavia during the Saalian, whilst it drained more ice from east of Svalbard during the Weichselian.