Hot-water drilling at Glaciar Perito Moreno, Southern Patagonia Icefield
Hot-water drilling at Glaciar Perito Moreno, Southern Patagonia Icefield
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DOI：
10.5331/bgr.28.27
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发表时间：
2010
影响因子：
1
通讯作者：
S. Sugiyama;P. Skvarca;Nozomu Naito;Kenta Tone;H. Enomoto;Kunio Shinbori;S. Marinsek;M. Aniya
中科院分区：
文献类型：
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作者：
S. Sugiyama;P. Skvarca;Nozomu Naito;Kenta Tone;H. Enomoto;Kunio Shinbori;S. Marinsek;M. Aniya
冰川佩里托莫雷诺是南巴塔哥尼亚冰原的主要淡水崩解冰川之一。其快速流动的特征可能是由于冰川床的高水压，然而，在巴塔哥尼亚从未观察到冰下条件，直到我们最近的任务。为了研究冰下水压在崩解冰川动力学中的作用，我们于2010年2月至3月在Glaciar佩里托莫雷诺进行了热水钻探。这项研究代表了巴塔哥尼亚有史以来第一次尝试热水冰川钻探。在距离终点4.7km的冰川上游钻了两个钻孔，发现冰厚515± 5 m，冰床位于冰前湖水位以下约330 m处。钻孔中的水位高于湖平面100米以上，这表明冰下水压力平衡了90%以上的冰覆盖层压力。在钻孔到达河床之前，钻孔中的水已经排干，这表明存在冰内排水系统。这些结果为了解冰解冰川的水力和水文条件提供了重要信息。为了钻探500米深的冰川，通过增加高压热水机的数量来改造现有的热水钻探系统。在Glaciar佩里托Moreno的钻井作业证实了该系统能够以50 mh-1的速度钻一个500 m深的钻孔，柴油的燃料消耗率为15.7 lh-1，汽油为3.9 lh-1。
Glaciar Perito Moreno is one of the major freshwater calving glaciers in the Southern Patagonia Icefield. Its fast-flowing characteristic is probably due to high water pressure at the glacier bed, however, subglacial conditions have never been observed in Patagonia until our recent undertaking. To investigate the role of subglacial water pressure in the calving glacier dynamics, we performed hot-water drilling at Glaciar Perito Moreno from February to March 2010. This study represents the first attempt ever at hot-water glacier drilling in Patagonia. Two boreholes were drilled to the bed at 4.7km upglacier from the terminus, where the ice was revealed to be 515±5m thick and the bed located at about 330m below the proglacial lake level. The water levels in the boreholes were >100m above the lake level, which indicates that more than 90% of the ice overburden pressure was balanced out by the subglacial water pressure. Water in the boreholes had drained away before the drilling reached the bed, suggesting the existence of an englacial drainage system. These results provide crucial information for understanding the hydraulic and hydrological conditions of calving glaciers. In order to drill a 500m deep glacier, an existing hot-water drilling system was adapted by increasing the number of high-pressure hot-water machines. The drilling operation at Glaciar Perito Moreno confirmed the system's capacity to drill a 500-m-deep borehole at a rate of 50mh-1 with fuel consumption rates of 15.7lh-1 for diesel and 3.9lh-1 for petrol.