Changes in ice dynamics, elevation and mass discharge of Dinsmoor-Bombardier-Edgeworth glacier system, Antarctic Peninsula
Changes in ice dynamics, elevation and mass discharge of Dinsmoor-Bombardier-Edgeworth glacier system, Antarctic Peninsula
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DOI：
10.1016/j.epsl.2015.06.047
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发表时间：
2015-10
影响因子：
5.3
通讯作者：
T. Seehaus;S. Marinsek;V. Helm;P. Skvarca;M. Braun
中科院分区：
文献类型：
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作者：
T. Seehaus;S. Marinsek;V. Helm;P. Skvarca;M. Braun
南极北方半岛是地球上变化最快的地区之一。1995年拉森-A冰架的解体导致支流冰川通过加速、表面降低和整体增加的冰量排放来调整。在这项研究中，我们调查这些变化的时间变化在丁斯莫尔-庞巴迪-埃奇沃思冰川系统通过分析密集的时间序列，从各种航天器和机载地球观测任务。涵盖了崩塌前冰架条件和随后到2014年的调整。我们的研究结果显示了冰川系统在分裂后几个月的反应，在1999年达到最大表面速度，达到8.8 m/d，随后在2014年下降到1.5 m/d。使用密集的时间序列的干涉派生TanDEM-X数字高程模型和摄影测量数据，指数函数拟合表面高程的下降。1995年至2014年，海拔1000米以下地区的高程变化至少为130±15米，2003年至2008年的变化率为1.315米/年。目前的变化率（2010-2014年）在1.7 m/a的范围内。质量不平衡计算不同的情况下的边界条件。最合理的结果是-40.7 ±3.9 Gt。1995-2014年期间，对海平面上升的贡献估计为18.8±1.8 Gt，相当于0.052±0.005 mm海平面当量。我们的分析和情景考虑表明，由于冰厚信息不够准确，仍然存在重大的不确定性。计算中的第二大不确定性是冰川表面质量平衡，但人们对此知之甚少。我们的时间序列分析有助于改进与GRACE数据的比较，并作为该地区冰川均衡隆起建模的输入。这项研究有助于更好地了解冰川系统如何适应冰架解体。
Abstract The northern Antarctic Peninsula is one of the fastest changing regions on Earth. The disintegration of the Larsen-A Ice Shelf in 1995 caused tributary glaciers to adjust by speeding up, surface lowering, and overall increased ice-mass discharge. In this study, we investigate the temporal variation of these changes at the Dinsmoor–Bombardier–Edgeworth glacier system by analyzing dense time series from various spaceborne and airborne Earth observation missions. Precollapse ice shelf conditions and subsequent adjustments through 2014 were covered. Our results show a response of the glacier system some months after the breakup, reaching maximum surface velocities at the glacier front of up to 8.8 m/d in 1999 and a subsequent decrease to∼ 1.5 m/d in 2014. Using a dense time series of interferometrically derived TanDEM-X digital elevation models and photogrammetric data, an exponential function was fitted for the decrease in surface elevation. Elevation changes in areas below 1000 m asl amounted to at least 130±15 m between 1995 and 2014, with change rates of∼ 3.15 m/a between 2003 and 2008. Current change rates (2010–2014) are in the range of 1.7 m/a. Mass imbalances were computed with different scenarios of boundary conditions. The most plausible results amount to− 40.7±3.9 Gt. The contribution to sea level rise was estimated to be 18.8±1.8 Gt, corresponding to a 0.052±0.005 mm sea level equivalent, for the period 1995–2014. Our analysis and scenario considerations revealed that major uncertainties still exist due to insufficiently accurate ice-thickness information. The second largest uncertainty in the computations was the glacier surface mass balance, which is still poorly known. Our time series analysis facilitates an improved comparison with GRACE data and as input to modeling of glacio-isostatic uplift in this region. The study contributed to a better understanding of how glacier systems adjust to ice shelf disintegration.