Ice content and interannual water storage changes of an active rock glacier in the dry Andes of Argentina
Ice content and interannual water storage changes of an active rock glacier in the dry Andes of Argentina
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DOI：
10.5194/tc-15-1187-2021
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Christian Halla;J. Blöthe;Carla Tapia Baldis;Darío Trombotto Liaudat;C. Hilbich;C. Hauck;L. Schrott
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文献类型：
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作者：
Christian Halla;J. Blöthe;Carla Tapia Baldis;Darío Trombotto Liaudat;C. Hilbich;C. Hauck;L. Schrott
抽象。定量的体积冰和水含量在活跃的岩石冰川是必要的，以估计其作为水的存储和贡献者在干旱山区集水区径流的作用。在阿根廷半干旱至干旱的安第斯山脉，活跃的岩石冰川由于分布广泛，可能构成重要的水库。然而，在这里，水的储存能力和它们的年际变化，迄今逃脱量化详细的实地研究。体积冰和水的含量进行了量化，使用岩石物理四相模型（4PM）的基础上互补电折射率（ERT）和地震折射层析成像（SRT）在不同位置的Dos Lenguas岩石冰川在上阿瓜内格拉盆地，阿根廷。我们使用无人机衍生的数字高程模型（DEM）推导了2016-17和2017-18期间Dos Lenguas岩石冰川的垂直和水平表面变化。2016- 2017年和2017- 2018年期间分别从差异DEM（DoD）得出的-36 mm yr-1和+27 mm yr-1的年际水储存变化表明，大量的年降水率可以储存在活动的岩石冰川中并从其中释放出来。不均匀的冰和水含量显示富冰的永冻土和地下永冻土层上，内和亚永冻土含水层。活动层和富冰的冻土控制着浅层地下水的圈闭和通道，从而调节着干旱山区集水区活动岩冰川的年际贮水量变化和释水量。活动的Dos Lenguas岩石冰川中的冰含量为1.7-2.0 × 109 kg，与覆盖不到3%高山集水区的地表冰相比，就像附近的其他地面冰沉积物一样，是一个重要的长期冰库。
Abstract. The quantification of volumetric ice and water contents in active rock glaciers is necessary to estimate their role as water stores and contributors to runoff in dry mountain catchments. In the semi-arid to arid Andes of Argentina, active rock glaciers potentially constitute important water reservoirs due to their widespread distribution. Here however, water storage capacities and their interannual changes have so far escaped quantification in detailed field studies. Volumetric ice and water contents were quantified using a petrophysical four-phase model (4PM) based on complementary electrical resistivities (ERT) and seismic refraction tomographies (SRT) in different positions of Dos Lenguas rock glacier in the Upper Agua Negra basin, Argentina. We derived vertical and horizontal surface changes of the Dos Lenguas rock glacier, for the periods 2016–17 and 2017–18 using drone-derived digital elevation models (DEM). Interannual water storage changes of −36 mm yr−1 and +27 mm yr−1 derived from DEMs of Difference (DoD) for the periods 2016–17 and 2017–18, respectively, indicate that significant amounts of annual precipitation rates can be stored in and released from the active rock glacier. Heterogeneous ice and water contents show ice-rich permafrost and supra-, intra- and sub-permafrost aquifers in the subsurface. Active layer and ice-rich permafrost control traps and pathways of shallow ground water, and thus regulate interannual storage changes and water releases from the active rock glacier in the dry mountain catchment. The ice content of 1.7–2.0 × 109 kg in the active Dos Lenguas rock glacier represents an important long-term ice reservoir, just like other ground ice deposits in the vicinity, if compared to surface ice that covers less than 3 % of the high mountain catchment.