Deformation motion tracks sliding changes through summer, western Greenland
Deformation motion tracks sliding changes through summer, western Greenland
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格陵兰岛西部夏季变形运动追踪滑动变化
DOI：
10.1017/jog.2021.87
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发表时间：
2021
影响因子：
3.4
通讯作者：
J. Harper
中科院分区：
文献类型：
--
作者：
N. Maier;N. Humphrey;T. Meierbachtol;J. Harper
格陵兰消融区的表面速度每年都有很大的变化，据推测主要是由滑动的变化驱动的。然而，融水强迫冰床耦合的变化也可以产生可变的变形运动，这会影响从表面测量推断的滑动变化的幅度，并提供了重要的上下文流动力学。我们研究时空变化的变形，滑动和表面速度超过2年的时间内使用GPS和一个密集的网络安装在格陵兰岛西部的消融区钻孔网格的测斜仪。我们发现变形运动轨迹的时间变化在整个夏季和整个测量期间的滑动变化。一个独特的空间变形和滑动模式也观察到钻孔网格内保持类似的冬季和夏季流动。我们认为，积极的季节性时间尺度上的协变滑动和变形的特点是被动的地区，耦合到区域进行瞬态强迫，空间格局是一致的变化，在当地的床地形。与仅从表面速度变化推断的结果相比，协变变形和滑动导致夏季滑动变化高估1.5 - 17%。这表明，在格陵兰岛的许多地方，夏季的滑动增长可能被高估了。
Abstract Surface speeds in Greenland's ablation zone undergo substantial variability on an annual basis which are presumed to mainly be driven by changes in sliding. Yet, meltwater-forced changes in ice–bed coupling can also produce variable deformation motion, which impacts the magnitude of sliding changes inferred from surface measurements and provides important context to flow dynamics. We examine spatiotemporal changes in deformation, sliding and surface velocities over a 2-year period using GPS and a dense network of inclinometers installed in borehole grid drilled in western Greenland's ablation zone. We find time variations in deformation motion track sliding changes through the summer and entire measurement period. A distinct spatial deformation and sliding pattern is also observed within the borehole grid which remains similar during winter and summer flow. We suggest that positively covarying sliding and deformation across seasonal timescales is characteristic of passive areas that are coupled to regions undergoing transient forcing, and the spatial patterns are consistent with variations in the local bed topography. The covarying deformation and sliding result in a 1.5–17% overestimate of sliding changes during summer compared to that inferred from surface velocity changes alone. This suggests that summer sliding increases are likely overestimated in many locations across Greenland.
影响因子：
18.3
作者：
Bartholomew, Ian;Nienow, Peter;Sole, Andrew
通讯作者：
Sole, Andrew
影响因子：
3.9
作者：
Davison, B. J.;Sole, A. J.;Nienow, P. W.
通讯作者：
Nienow, P. W.