Glacial Isostatic Adjustment over Antarctica from combined ICESat and GRACE satellite data
Glacial Isostatic Adjustment over Antarctica from combined ICESat and GRACE satellite data
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DOI：
10.1016/j.epsl.2009.10.013
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发表时间：
2009-11
影响因子：
5.3
通讯作者：
R. Riva;B. Gunter;T. Urban;B. Vermeersen;R. Lindenbergh;M. Helsen;J. Bamber;R. Wal;M. Broeke;B. Schutz
中科院分区：
文献类型：
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作者：
R. Riva;B. Gunter;T. Urban;B. Vermeersen;R. Lindenbergh;M. Helsen;J. Bamber;R. Wal;M. Broeke;B. Schutz
相对于北半球而言，最近的米兰科维奇旋回期间南极洲的冰川历史受到的限制很少。因此，南极冰盖的大规模变化对全球海平面变化的贡献及其未来演变的预测仍然不确定。冰川均衡调整（GIA）过程代表了固体地球对晚更新世去冰作用的持续响应，因此提供了有关南极冰川历史的信息。此外，对GIA的了解不足妨碍了通过卫星重力测量确定南极物质平衡的当今变化。前人的研究已经为通过卫星重测与卫星测高相结合，区分正在进行的GIA和当代冰质量变化信号奠定了理论基础。这一区别之所以成为可能，是因为全球地理变化引起的变化（涉及相对致密的岩石）与由冰或雪厚度变化引起的变化（由于这些材料的密度较低）相比，将产生不同的地形和重力变化组合；然而，迄今尚未产生结论性的结果。在这里，我们表明，通过结合2003年3月至2008年3月期间ICESat和GRACE卫星任务的激光测高和重力数据，GIA的贡献确实可以分离出来。推断出的南极大陆上的GIA信号是通过卫星技术直接观测得到的第一个结果，有力地支持了冰川地质研究得出的晚更新世冰川模型。GIA对grace导出的质量平衡估计的影响发现为100±67Gt/年。
The glacial history of Antarctica during the most recent Milankovitch cycles is poorly constrained relative to the Northern Hemisphere. As a consequence, the contribution of mass changes in the Antarctic ice sheet to global sea-level change and the prediction of its future evolution remain uncertain. The process of Glacial Isostatic Adjustment (GIA) represents the ongoing response of the solid Earth to the Late-Pleistocene deglaciation and, therefore, provides information about Antarctic glacial history. Moreover, insufficient knowledge of GIA hampers the determination of present-day changes in the Antarctic mass balance through satellite gravity measurements. Previous studies have laid the theoretical foundation for distinguishing between signals of ongoing GIA and contemporary ice mass change through the combination of satellite gravimetry and satellite altimetry. This distinction is made possible by the fact the GIA-induced changes (involving relatively dense rock) will produce a different combination of topography and gravity change than those produced by variations in ice or firn thickness (due to the lower density of these materials); however, no conclusive results have been produced to date. Here we show that, by combining laser altimetry and gravity data from the ICESat and GRACE satellite missions over the period March 2003–March 2008, the GIA contribution can indeed be isolated. The inferred GIA signal over the Antarctic continent, which represents the first result derived from direct observations by satellite techniques, strongly supports Late-Pleistocene ice models derived from glacio-geologic studies. The GIA impact on GRACE-derived estimates of mass balance is found to be 100±67Gt/yr.