Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change
Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change
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DOI：
10.1073/pnas.1204664109
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发表时间：
2012-07-24
影响因子：
11.1
通讯作者：
Francis, Olivier
中科院分区：
文献类型：
--
作者：
Bevis, Michael;Wahr, John;Francis, Olivier
格陵兰全球定位系统网络（GNET）使用全球定位系统（GPS）来测量格陵兰冰盖边缘附近暴露的基岩的位移。整个网络正在上升，以应对过去和现在的冰量变化。地壳位移在很大程度上是由叠加在持续趋势上的年度振荡造成的。振荡是由地球对冰质量和空气质量的季节性变化的弹性响应驱动的（即，大气压）。观测到的垂直速度更高，往往比预测的冰后反弹（PGR）率高得多，这意味着隆起通常是由固体地球的瞬时弹性响应当代冰量损失，而不是PGR。叠加在长期趋势上，在2010年大约六个月的时间里，许多GNET台站积累了异常的隆起“脉冲”。这种异常抬升与2010年融日异常在空间上相关。
The Greenland GPS Network (GNET) uses the Global Positioning System (GPS) to measure the displacement of bedrock exposed near the margins of the Greenland ice sheet. The entire network is uplifting in response to past and present-day changes in ice mass. Crustal displacement is largely accounted for by an annual oscillation superimposed on a sustained trend. The oscillation is driven by earth's elastic response to seasonal variations in ice mass and air mass (i.e., atmospheric pressure). Observed vertical velocities are higher and often much higher than predicted rates of postglacial rebound (PGR), implying that uplift is usually dominated by the solid earth's instantaneous elastic response to contemporary losses in ice mass rather than PGR. Superimposed on longer-term trends, an anomalous 'pulse' of uplift accumulated at many GNET stations during an approximate six-month period in 2010. This anomalous uplift is spatially correlated with the 2010 melting day anomaly.