摘要
南极冰盖内部等时层记录了不同时期冰盖表面的特征及其演变,蕴含了丰富的冰下环境信息。目前,已成为研究大空间尺度与长时间尺度上南极冰盖演化及其底部环境的重要媒介。地球物理观测和数值模拟技术的综合使用,实现了南极冰盖内部等时层在大陆尺度上的可视化。通过这些内部等时层,冰川学研究将南极冰盖内部的古冰流与千年至百万年时间尺度的地貌及冰下环境的变化细节联系起来,得到了一系列数量化的结果。针对南极冰盖,综述产生内部等时层的冰盖动力学物理机理及其在冰川学上的应用,评估在五个方面的运用:(1)深冰芯断代与选址;(2)冰盖动力学过程;(3)冰盖物质平衡;(4)冰盖稳定性;(5)冰下环境。另外,基于对内部等时层的已有认识,对未来在内部等时层研究中可能需要强化的领域进行了归纳:(1)发展更精细描述并测试内部等时层结构时空变化的数值模拟技术框架面临的挑战;(2)如何从内部等时层蕴含的信息推断鉴别以目前南极冰盖作为初始条件的冰盖质量变化;(3)为获得更高分辨率的内部等时层结构图像,得到关于冰盖内部冰体形变与演化的更多数量化信息,如何强化冰盖冰下环境的重复观测。
Radar isochronous layers,reflect the surface characteristics of ice of different periods and their variation within the Antarctic ice sheet,and contain a wealth of subglacial environmental information. Isochronous layers have increasingly been used as proxies in investigations into the evolution and subglacial environment of the Antarctic ice sheet over considerable spatiotemporal scales. The integration of geophysical observations and numerical simulation technology has enabled the visualization of these layers over the continental scale. Using these internal isochronous layers,glaciology research has achieved a number of quantitative results by relating millennial-timescale subglacial geomorphology with the paleo-ice stream. In this review concerning the Antarctic ice sheet,we summarize the physical mechanism of the internal layer and its benefit to glaciology,and evaluate its application to the following：（ 1）siting and dating of deep ice cores,（ 2） ice sheet dynamics,（ 3） ice sheet mass balance,（ 4） ice sheet stability,and（ 5） the subglacial environment. In addition,based on our understanding of internal isochronous layers,we outline a number of challenges to be addressed in the future.（ 1） The development and testing of numerical icesheet models with more elaborate frameworks that include the structure of internal layers,such as their temporal and spatial variations.（ 2） The identification of ice mass change based on the internal layers using the current Antarctic ice sheet as the initial conditions.（ 3） The increase of observations of the subglacial environment,to obtain higher resolution quantitative images of the isochronous layer structure and ice deformation.
出处
《极地研究》
CAS
CSCD
2015年第1期104-114,共11页
Chinese Journal of Polar Research
基金
全球变化研究国家重大科学研究计划(973计划)(2012CB957702和2013CBA01804)
国家自然科学基金(41376192和40906101)
国家海洋局极地考察办公室对外合作支持项目(IC201214)
上海市自然科学基金(13ZR1445300)资助
关键词
南极冰盖内部等时层
地球物理
雷达
数值
模拟
Antarctic ice sheet
isochronous layers
geophysical
radar
numerical modeling
