Deep draft icebergs from the Barents Ice Sheet during MIS 6 are consistent with erosional evidence from the Lomonosov Ridge, central Arctic
Deep draft icebergs from the Barents Ice Sheet during MIS 6 are consistent with erosional evidence from the Lomonosov Ridge, central Arctic
复制标题
DOI：
10.1029/2010gl045299
复制
发表时间：
2010-12-04
影响因子：
5.2
通讯作者：
Green, J. A. Mattias
中科院分区：
文献类型：
--
作者：
Green, Clare L.;Bigg, Grant R.;Green, J. A. Mattias
北极中部Lomonosov山脊上的冰山冲刷痕迹表明，北极曾经存在吃水超过850米的冰山，而在耶尔马克高原观察到的类似侵蚀模式表明，其中一些深龙骨冰山通过弗拉姆海峡离开北极进入北欧海。为了研究深吃水“巨型”冰山能否到达洛蒙诺索夫山脊，用一个中等复杂的气候模式和一个动力和热力学冰山模式来模拟MIS6期间巴伦支河冰盖的崩塌过程。许多不同大小冰山的模拟表明，从弗朗茨·维多利亚海槽附近播撒的深吃水护堤确实可能到达了海脊，而其他护堤穿过耶尔马克高原，通过弗拉姆海峡离开。护堤吃水主要决定航道，受护堤质量、长度和宽度的影响很小。这项工作与之前的推测一致，即这些冰山起源于海洋同位素第六阶段(MIS6；140 ka BP)期间巴伦支河冰盖的解体，但表明它们更有可能来自该冰盖的西部，而不是东部的主要冰流。冰山融化对翻转环流的长期影响比同等量级的淡水脉冲更为严重，因此在古气候模型中正确描述冰山具有重要意义。引用：Green，C.L.，G.R.Bigg和J.A.M.Green(2010)，在MIS6期间来自巴伦支河冰盖的深吃水冰山与北极中部洛蒙诺索夫山脉的侵蚀证据是一致的，地球物理。莱特，37岁，L23606，DOI：10.1029/2010GL045299。
Iceberg scour marks on the Lomonosov Ridge in the central Arctic imply that bergs with drafts exceeding 850 m once existed in the Arctic, whereas similar erosion patterns observed on the Yermak Plateau suggest that some of these deep-keeled icebergs exited the Arctic through the Fram Strait into the Nordic Seas. An intermediate complexity climate model with a dynamic and thermodynamic iceberg model is used to simulate the collapse of the Barents Ice Sheet during MIS 6 with the purpose of investigating if deep-draft "mega"-icebergs can reach and ground on the Lomonosov Ridge. A number of simulations with different iceberg sizes show that deep-draft bergs seeded from near the Franz Victoria Trough could indeed have reached the Ridge, whereas other bergs crossed the Yermak Plateau and exited through the Fram Strait. The draft of the bergs mainly determines the trajectory, with only minor influence from the mass, and length and width of the bergs. This work is consistent with previous speculation that these icebergs originated from the disintegration of the Barents Ice Sheet during Marine Isotope Stage 6 (MIS 6; 140 ka BP), but suggests their origin was more likely to be from the western, rather than eastern, major ice stream of that ice sheet. The long-term impact on the overturning circulation from melting icebergs is more severe than that from a freshwater pulse of equivalent magnitude, and a correct representation of icebergs in paleoclimate models is therefore of importance. Citation: Green, C. L., G. R. Bigg, and J. A. M. Green (2010), Deep draft icebergs from the Barents Ice Sheet during MIS 6 are consistent with erosional evidence from the Lomonosov Ridge, central Arctic, Geophys. Res. Lett., 37, L23606, doi:10.1029/2010GL045299.