The effect of seafloor topography in the Southern Ocean on tabular iceberg drifting and grounding
The effect of seafloor topography in the Southern Ocean on tabular iceberg drifting and grounding
复制标题
南大洋海底地形对板状冰山漂移和搁浅的影响
DOI：
10.1007/s11430-016-9014-5
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发表时间：
2017
影响因子：
5.7
通讯作者：
Wen JiaHong
中科院分区：
文献类型：
--
作者：
Li Tian;Liu Yan;Cheng Xiao;Ouyang LunXi;Li XinQing;Liu JiPing;Shokr Mohammed;Hui FengMing;Zhang Jing;Wen JiaHong
南极板状冰山是冰盖-冰架-海洋系统中重要的活动组分。海底地形是影响冰山漂移和搁浅的关键因素，但尚未得到充分研究。本研究利用杨百翰大学的Bedmap-2数据集和冰山路线跟踪数据分析了海底地形对南极板状冰山漂移和搁浅的影响。结果突出了以下几点。(1)冰山搁浅事件的数量分布和搁浅冰山的追踪点主要受冰山吃水的影响，在水深200 ~ 300 m的海水中达到峰值。自由漂流冰山的跟踪点数量和线速度峰值出现在南极斜坡前缘（水深约500米）。(2)从冰架前缘崩解的小型冰山可能搁浅区域的面积占南极海岸线外围（362万km 2）以外水深小于2000 m的海域面积的28%。其空间分布主要集中在东南极和南极半岛附近。长轴大于18.5km（水深小于800 m）的大型板状冰山可能搁浅区面积占海域面积的74%。(3)在水深小于2000 m的海域，冰山漂流速度与水深呈正相关（R= 0.85，P <0.01）。这一结果证实了海底地形起伏引起的水深变化对冰山漂移速度的影响。
Antarctic tabular icebergs are important active components in the ice sheet-ice shelf-ocean system. Seafloor topography is the key factor that affects the drifting and grounding of icebergs, but it has not been fully investigated. This study analyzes the impact of seafloor topography on the drifting and grounding of Antarctic tabular icebergs using Bedmap-2 datasets and iceberg route tracking data from Brigham Young University. The results highlight the following points. (1) The quantitative distributions of iceberg grounding events and the tracking points of grounded icebergs are mainly affected by iceberg draft and reach their peak values in sea water with depths between 200 m and 300 m. The peak tracking point number and linear velocity of free-drifting icebergs are found in the Antarctic Slope Front (water depth of approximately 500 m). (2) The area of possible grounding regions of small-scale icebergs calved from ice shelf fronts accounts for 28% of the sea area at water depths less than 2000 m outside the Antarctic coastline periphery (3.62 million km2). Their spatial distribution is mainly around East Antarctica and the Antarctic Peninsula. The area of possible grounding regions of large tabular icebergs with long axes larger than 18.5 km (in water depths of less than 800 m) accounts for 74% of the sea area. (3) The iceberg drifting velocity is positively correlated with ocean depth in areas where the depth is less than 2000 m (R=0.85,P<0.01). This result confirms the effect of water depth variations induced by seafloor topography fluctuations on iceberg drifting velocity.