Glaciers distinct from the Greenland and Antarctic ice sheets are currently losing mass rapidly with direct and severe impacts on the habitability of some regions on Earth as glacier meltwater contributes to sea-level rise and alters regional water resources in arid regions. In this review, we present the different techniques developed during the last two decades to measure glacier mass change from space: digital elevation model (DEM) differencing from stereo-imagery and synthetic aperture radar interferometry, laser and radar altimetry and space gravimetry. We illustrate their respective strengths and weaknesses to survey the mass change of a large Arctic ice body, the Vatnajökull Ice Cap (Iceland) and for the steep glaciers of the Everest area (Himalaya). For entire regions, mass change estimates sometimes disagree when a similar technique is applied by different research groups. At global scale, these discrepancies result in mass change estimates varying by 20%–30%. Our review confirms the need for more thorough inter-comparison studies to understand the origin of these differences and to better constrain regional to global glacier mass changes and, ultimately, past and future glacier contribution to sea-level rise.

中文翻译：

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从太空测量冰川质量变化——综述

与格陵兰岛和南极冰原不同的冰川目前正在迅速失去质量，对地球上某些地区的宜居性产生直接和严重的影响，因为冰川融水导致海平面上升并改变干旱地区的区域水资源。在这篇综述中，我们介绍了过去二十年开发的用于从空间测量冰川质量变化的不同技术：数字高程模型 (DEM) 不同于立体图像和合成孔径雷达干涉测量法、激光和雷达测高法以及空间重力测量法。我们说明了它们各自的优缺点，以调查北极大冰体瓦特纳冰盖（冰岛）和珠穆朗玛峰地区（喜马拉雅山）陡峭冰川的质量变化。对于整个地区，当不同的研究小组应用类似的技术时，质量变化的估计有时会不一致。在全球范围内，这些差异导致质量变化估计值相差 20%–30%。我们的审查证实需要进行更彻底的相互比较研究，以了解这些差异的起源，并更好地限制区域到全球冰川质量的变化，并最终限制过去和未来冰川对海平面上升的贡献。