基于冰雷达探测与高阶冰盖数值模式的Dome A昆仑站深冰芯钻探区域的冰盖动力学研究

Currently,the deep ice core drilling program in Kunlun station has been constructed.The significant information of ice-sheet dynamics around Dome A is needed.The information is used to infer the qualitative details from the mass balance, the subglacial and subsurface conditions, basal erosion and melting,and the stratigraphic correlation of ice cores.In East Antarctica,very little is known about former ice flow and subglcial environment.Here,along the profiles,we collect the datasets of radar echo sounding,and use several high-order ice-sheet models,to calculate the spectral roughness of the subglacial topography，to classify qualitatively the continuous isochrones information revealed from the radar echo sounding and identify the correlation with the corresponding disturbed ice flow.Then we reconstruct the spatial and time variation in ice accumulation rates of past,and simulate the evolution of the ice velocity、the ice thickness and the temperature.Further application of the qualitative deails can be used to reveal the ice-sheet dynamics characteristics around Kunlun station,and benefit the ice coring program.

随着Dome A昆仑站地区深冰芯钻探计划的推进，揭示昆仑站所在的Dome A地区冰盖内部的动力学信息对于昆仑站的深冰芯钻探及其研究日益迫切。冰盖的物质平衡、冰下与表面地形、底部侵蚀与消融等控制着冰盖动力信息的空间分布与演化。在东南极，由于客观环境的限制，我们对于古冰流和冰下环境的理解非常有限。在本研究中，我们收集涵盖Dome A昆仑站地区的冰盖断面雷达数据，结合高阶冰盖数值模式，进行雷达信号和信号空白区（EFZ）谱分析，对内部等时层雷达信息进行数值化分类及其与冰流扰动的相关性分析，模拟反演冰盖深部古积累率及其空间与时间分布；模拟冰盖断面的流速、冰厚以及温度的演化。揭示昆仑站附近的冰盖动力学特征，从而直接服务于昆仑站深冰芯钻探计划。

通过考察获得的昆仑站所在的Dome A地区大范围的冰雷达探测数据，生成了冰穹A新的冰盖内部的三维结构图，通过数值模式重建了冰穹A区域过去6个不同时期16.1万年的平均古积累率，发现并验证了Gamburtsev冰下山脉区域存在的冰底再冻结和底部生长现象，通过发展各向异性三维冰盖动力学模式模拟评估了昆仑站深冰芯钻探点的年代-深度关系，获得了昆仑站下方深部温度及冰盖断面的温度分布；至少超过70万年的区域深度-年代关系估计以及冰流状态等模拟结果，为昆仑站的深冰芯钻探工作提供了重要理论支撑。