Greenland's future contribution to sea-level rise is strongly dependent on the extent to which dynamic perturbations, originating at the margin, can drive increased ice flow within the ice-sheet interior. However, reported observations of ice dynamical change at distances >~50 km from the margin have a very low spatial and temporal resolution. Consequently, the likely response of the ice-sheet's interior to future oceanic and atmospheric warming is poorly constrained. Through combining GPS and satellite-image-derived ice velocity measurements, we measure multi-decadal (1993–1997 to 2014–2018) velocity change at 45 inland sites, encompassing all regions of the ice sheet. We observe an almost ubiquitous acceleration inland of tidewater glaciers in west Greenland, consistent with acceleration and retreat at glacier termini, suggesting that terminus perturbations have propagated considerable distances (>100 km) inland. In contrast, outside of Kangerlussuaq, we observe no acceleration inland of tidewater glaciers in east Greenland despite terminus retreat and near-terminus acceleration, and suggest propagation may be limited by the influence of basal topography and ice geometry. This pattern of inland dynamical change indicates that Greenland's future contribution to sea-level will be spatially complex and will depend on the capacity for dynamic changes at individual outlet glacier termini to propagate inland.

中文翻译：

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格陵兰冰盖海洋终止冰川内陆复杂的多年代际冰动态变化

格陵兰岛未来对海平面上升的贡献在很大程度上取决于源自边缘的动态扰动可以推动冰盖内部冰流增加的程度。然而，据报道，在距离边缘 >~50 公里处观测到的冰动态变化具有非常低的空间和时间分辨率。因此，冰盖内部对未来海洋和大气变暖的可能反应很少受到限制。通过结合 GPS 和卫星图像衍生的冰速测量，我们测量了 45 个内陆地点的多年代（1993-1997 年至 2014-2018 年）速度变化，包括冰盖的所有区域。我们观察到格陵兰西部潮水冰川内陆几乎无处不在的加速，与冰川终点的加速和退缩一致，表明终点扰动已经向内陆传播了相当长的距离（> 100 km）。相比之下，在 Kangerlussuaq 之外，尽管终点退缩和近终点加速，我们观察到格陵兰东部潮水冰川内陆没有加速，并表明传播可能受到基础地形和冰几何形状的影响。这种内陆动态变化模式表明，格陵兰岛未来对海平面的贡献在空间上将是复杂的，并且将取决于各个出口冰川末端的动态变化向内陆传播的能力。并建议传播可能受到基础地形和冰几何形状的影响。这种内陆动态变化模式表明，格陵兰岛未来对海平面的贡献在空间上将是复杂的，并且将取决于各个出口冰川末端的动态变化向内陆传播的能力。并建议传播可能受到基础地形和冰几何形状的影响。这种内陆动态变化模式表明，格陵兰岛未来对海平面的贡献在空间上将是复杂的，并且将取决于各个出口冰川末端的动态变化向内陆传播的能力。