Rapid crustal uplift in Patagonia due to enhanced ice loss
Rapid crustal uplift in Patagonia due to enhanced ice loss
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DOI：
10.1016/j.epsl.2009.10.021
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发表时间：
2010-01-15
影响因子：
5.3
通讯作者：
Fritsche, M.
中科院分区：
文献类型：
--
作者：
Dietrich, R.;Ivins, E. R.;Fritsche, M.
2003年至2006年，在南巴塔哥尼亚冰原（SPI）的东北边缘，利用全球定位系统（GPS）测量的地壳垂直抬升速率为39 mm yr（-1）。这是有史以来最大的现代冰川均衡率。SPI的快速熔化和独特的区域板窗构造相结合，促进了相对较低的粘度，是我们对观测结果的解释的核心。这两种效应导致短弛豫时间与在可比时间尺度上变化的冰荷载的强烈相互作用。GPS观测资料将冰损失与小冰期（LIA）时间尺度上的软粘弹性均衡流响应联系起来，包括观测期间的冰损失。结果与我们的模型预测的一致性强有力地表明巴塔哥尼亚大的地壳隆起是由于自LIA终止以来加速的冰川消耗，有效的区域地幔粘度接近4.0-8.0 x 10（18）Pa s。一个世纪之久的冰原缩小，其速度约为当代损失率的1/4 - 1/2，与过去50-100年估计的多十年尺度温度趋势一致，事实上，这是任何能够解释隆升数据的模型的一个关键特征。(C)2009 Elsevier B. V.保留所有权利。
A vertical crustal uplift rate of 39 mm yr(-1) is measured between 2003 and 2006 using Global Positioning System (GPS) measurements at the northeastern edge of the Southern Patagonia Icefield (SPI). This is the largest present-day glacial isostatic rate ever recorded. The combination of SPI's rapid melting and the unique regional slab-window tectonics that promotes a relatively low viscosity, is central to our interpretation of the observations. The two effects lead to a strong interaction of short relaxation times with ice loads that change on a comparable time scale. The profile of GPS observations link ice loss to the soft viscoelastic isostatic flow response over the time scale of the Little Ice Age (LIA), including ice loss in the period of observation. The agreement of the results with our model predictions strongly suggests the large crustal uplift in Patagonia is due an accelerated glacier wasting since the termination of the LIA and that the effective regional mantle viscosity is near 4.0-8.0 x 10(18) Pa s. A century-long diminution of the icefields, at rates that are about 1/4 - 1/2 the contemporary loss rates, is consistent with multidecadal-scale temperature trends estimated for the past 50-100 years and is, in fact, a key feature in any model capable of explaining the uplift data. (C) 2009 Elsevier B.V. All rights reserved.