Abstract The Southern Patagonian Icefield is located in an area with a complex tectonic-rheological structure and is affected by intense glacial-isostatic adjustment and rapid ice retreat. Geodetic observations of loading effects provide information on earth structure. Perito Moreno Glacier repeatedly dams the Brazo Rico and Brazo Sur branches of Lago Argentino. The rupture of the ice dam applies an intense hydrological load signal which results in an elastic response of the solid earth. We present a modelling procedure to predict loading effects in response to water-level changes in Brazo Rico. The output is compared with site displacements observed by GNSS during the 2016 rupture event. Our results show that water-level changes in Brazo Rico exceeding 5 m produce vertical deformations detectable with GNSS observations. A geodetic observation of loading effects at magnitudes similar to those of the maximum historic event in 1956 could provide meaningful constraints on elastic earth models. We discuss consequences for the determination of accurate deformation rates, implications for our understanding of the intense uplift observed at the Southern Patagonian Icefield, and requirements and prospects for obtaining geodetic observations of the loading effects of future rupture events.

中文翻译：

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佩里托莫雷诺冰川大坝破裂——一个反复出现的自然实验来探测固体地球弹性

摘要 巴塔哥尼亚南部冰原地处构造流变结构复杂的地区，受到强烈的冰川均衡调整和冰层快速退缩的影响。载荷效应的大地观测提供了地球结构的信息。Perito Moreno Glacier 多次在 Lago Argentino 的 Brazo Rico 和 Brazo Sur 分支筑坝。冰坝的破裂施加了强烈的水文载荷信号，导致固体地球的弹性响应。我们提出了一个建模程序来预测响应 Brazo Rico 水位变化的负载效应。输出与 2016 年破裂事件期间 GNSS 观测到的站点位移进行了比较。我们的结果表明，Brazo Rico 超过 5 m 的水位变化会产生可通过 GNSS 观测检测到的垂直变形。在类似于 1956 年最大历史事件的震级上对载荷效应进行大地测量观测可以为弹性地球模型提供有意义的约束。我们讨论了确定准确变形率的后果，对我们理解在南巴塔哥尼亚冰原观察到的强烈隆升的影响，以及获得未来破裂事件加载效应的大地测量观测的要求和前景。