Pleistocene iceberg dynamics on the west Svalbard margin: Evidence from bathymetric and sub-bottom profiler data
Pleistocene iceberg dynamics on the west Svalbard margin: Evidence from bathymetric and sub-bottom profiler data
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斯瓦尔巴群岛西部边缘的更新世冰山动力学：来自测深和海底剖面仪数据的证据
DOI：
10.1016/j.quascirev.2017.01.019
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发表时间：
2017-04
影响因子：
4
通讯作者：
Soryal Simon M.
中科院分区：
文献类型：
--
作者：
Zhao Fang;Minshull Timothy A.;Crocker Anya J.;Dowdeswell Julian A.;Wu Shiguo;Soryal Simon M.
大型冰山通过犁开海床留下了它们漂移的证据，从而提供了厚冰盖崩解事件的地质记录。我们解释大规模的曲线凹陷西部斯瓦尔巴群岛边缘犁痕所产生的龙骨的冰山，在海底上，因为他们漂流通过这一地区。在现代水深300米至1000米处，在两个不同的地层单位中发现了冰山犁痕。将沉积物岩心数据与浅地层剖面仪数据的地震地层学相结合，表明犁痕的形成分为两个阶段：（1）海洋同位素阶段（MIS）6;（2）MIS 2，表明在萨利亚晚期和魏克塞尔晚期冰川作用期间，斯瓦尔巴特群岛西部边缘存在大型漂流冰山。沿着斯瓦尔巴群岛西部边缘的沉积物岩心数据表明，23.7 ± 0.2 ka时大量搬运的沉积物急剧增加，与较年轻的冰山犁削表面的MIS 2年龄一致。犁痕主要有两个方向：西南-东北和南北。向北浅的南北向犁痕表明，冰山从南部漂移，具有西南-东北分量，标志着西斯匹次卑尔根海流（WSC）分裂为耶尔马克斜坡海流（YSC）和北斯匹次卑尔根海流（NSC）的区域。大型MIS 6和MIS 2冰山很可能来自北冰洋。我们认为，这些冰山可能离开北冰洋向南通过弗拉姆海峡，并在挪威-格陵兰海内循环，然后由WSC向北沿着斯瓦尔巴特群岛边缘。MIS 2期间斯瓦尔巴群岛西部边缘冰山的另一个可能来源是终止于巴伦支海西部的冰盖，冰山从那里向北漂移。
Large icebergs leave evidence of their drift via ploughing of the seabed, thereby providing a geological record of episodes of calving from thick ice sheets. We interpret large-scale curvilinear depressions on the western Svalbard margin as ploughmarks produced by the keels of icebergs that grounded on the seafloor as they drifted through this area. Iceberg ploughmarks were identified at modern water depths between 300 m and 1000 m and in two distinct stratigraphic units. Combining data from sediment cores with seismic stratigraphy from sub-bottom profiler data suggests that the ploughmarks developed in two phases: (1) during Marine Isotope Stage (MIS) 6; and (2) during MIS 2, indicating the presence of large drifting icebergs on the western Svalbard margin during both the Late Saalian and Late Weichselian glaciations. Sediment-core data along the western Svalbard margin indicate a sharp increase in mass-transported sediments dated at 23.7 ± 0.2 ka, consistent with the MIS 2 age of the younger iceberg-ploughed surface. The ploughmarks are oriented in two main directions: SW-NE and S-N. S-N oriented ploughmarks, which shallow to the north, indicate iceberg drift from the south with a SW–NE component marking the zone of splitting of the West Spitsbergen Current (WSC) into the Yermak Slope Current (YSC) and North Spitsbergen Current (NSC). Large MIS 6 and MIS 2 icebergs most likely had an Arctic Ocean source. We suggest that these icebergs probably left the Arctic Ocean southward through Fram Strait and circulated within the Norwegian-Greenland Sea before being transported northwards along the Svalbard margin by the WSC. An additional likely source of icebergs to the western Svalbard margin during MIS 2 was the ice-sheet terminating in the western Barents Sea, from which icebergs drifted northward.
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影响因子：
2.3
作者：
C. Pudsey;P. Barker;R. Larter
通讯作者：
C. Pudsey;P. Barker;R. Larter
影响因子：
1.9
作者：
D. Darby;Paula Zimmerman
通讯作者：
D. Darby;Paula Zimmerman
影响因子：
--
作者：
Katarzyna Zamelczyk;T. L. Rasmussen;K. Husum;F. Godtliebsen;M. Hald
通讯作者：
Katarzyna Zamelczyk;T. L. Rasmussen;K. Husum;F. Godtliebsen;M. Hald
影响因子：
16.6
作者：
Jakobsson M;Nilsson J;Anderson L;Backman J;Björk G;Cronin TM;Kirchner N;Koshurnikov A;Mayer L;Noormets R;O'Regan M;Stranne C;Ananiev R;Barrientos Macho N;Cherniykh D;Coxall H;Eriksson B;Flodén T;Gemery L;Gustafsson Ö;Jerram K;Johansson C;Khortov A;Mohammad R;Semiletov I
通讯作者：
Semiletov I
影响因子：
2.2
作者：
D. Ottesen;J. Dowdeswell;J. Landvik;J. Mienert
通讯作者：
D. Ottesen;J. Dowdeswell;J. Landvik;J. Mienert