Characteristics of recent glacier variations in Patagonia, Southern Andes

该项目旨在调查巴塔哥尼亚冰川响应气候变化的变化过程和机制。1990年11月9日至12月27日在南巴塔哥尼亚的乌普萨拉、莫雷诺和廷德尔冰川进行了实地研究。1991年预算年度进行了分析，得到以下结果：1）冰川表面高度：在三条冰川消融区，用三角测量法获得了表面剖面。从1985年到1990年，廷德尔冰川变薄了约20 m，这是一个相当大的变薄率。2）冰川锋的变化：根据野外观测、航空照片和卫星图像，可以清楚地看出，乌普萨拉冰川已处于一个约500 m/年的退缩阶段，而莫雷诺冰川被认为已接近平衡状态。在北方冰原周围进行的航空摄影调查表明，西侧冰川退缩的程度大于东侧。3）冰流：在乌普萨拉冰川，在中碛附近获得了约3.6 m/d的相当快的速度。莫雷诺冰川的沿着横线的速度范围为0.38 - 2 m/d，廷德尔冰川的速度范围为0.07 - 0.51 m/d。4）冰厚：在廷德尔冰川，使用脉冲雷达成功地获得了冰厚，最大值在距左缘3 km处约为600 m。5）气象条件：研究了廷德尔冰川的一些气象特征和冰的消融情况。6）地貌：通过分析冰川沉积物和冰碛系统，阐明了乌普萨拉冰川自晚全新世以来的变化。研究了廷德尔冰川周围冰碛物和冰冲地形的分布。

The project aims at investigating the processes and mechanisms of variations of Patagonian glaciers in response to climatic changes. Field researches were carried out from 9 November to 27 December 1990 at Upsala, Moreno and Tyndall glaciers in the Southern Patagonia. Analyses were made in the budget year of 1991, and the following results were obtained.1) Surface heights of glaciers : Surface profiles were obtained by the triangulation method at the ablation areas of the three glaciers. Tyndall Glacier has thinned by about 20 m from 1985 to 1990, that is a considerably large thinning rate.2) Variations in glacier fronts : Based on field observations, aerial photographs and satellite images, it became clear that Upsala Glacier has been in a recessive stage with a rate of about 500 m/year, whereas Moreno Glacier is considered to have been nearly in the equilibrium condition. An aerial photographic survey made around the Northern Icefield revealed that glaciers on the- western side have retreated in greater degree than on the eastern side.3) Ice-flow : At Upsala Glacier, a considerably rapid velocity of about 3.6 m/d was obtained near the medial moraine. Velocities along transverse lines ranged from 0.38 to 2 m/d at Moreno Glacier, and from 0.07 to 0.51 m/d at Tyndall Glacier.4) Ice thickness : Ice thicknesses were successfully obtained using an impulse radar at Tyndall Glacier, the maximum being about 600 m at 3 km from the left margin. Distribution of foliation patterns and medial moraines were also analyzed.5) Meteorological conditions : Some meteorological characteristics and ablation of ice were studied at Tyndall Glacier.6) Geomorphology : By analyzing the glacial deposits and moraine systems, variation of Upsala Glacier since the late Holocene was elucidated. Distributions of moraines and ice-scoured topography were also investigated around Tyndall Glacier.