ABSTRACT Glaciers in central Svalbard are retreating since their Little Ice Age maximum, dated in the area to around 1900. Past areal extent of glaciers can confidently be reconstructed based on end moraine position. However, reconstructions of thickness and volume of glaciers remain relatively more complicated and uncertain. In this study, past changes in thickness and volume of the Ferdinand Glacier was reconstructed based on Structure-from-Motion techniques and field dGPS measurements in combination with analysis of historic photos from 1908 and aerial photos from 1938. According to the comparison of the historic and recent photograph, the 1908 glacier front height was estimated to 50 m and the glacier volume to 91.5 mil m3 and the 1938 glacier volume estimated to 76.1 mil m3, in comparison to 6.29 mil m3 in 2014. This means more than 90% loss of volume since 1938. Melting of the glacier in the first half of the twentieth century resulted in thinning and lowering of the glacier surface together with substantial ice volume loss, whereas the areal extent was almost not affected. Considering the 2014 mean ice thickness, together with ongoing climate warming, it is likely that the Ferdinand Glacier will completely disappear within the next 30 years.

中文翻译：

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20 世纪早期斯瓦尔巴费迪南德冰川的演变，基于历史照片和运动结构技术

摘要 斯瓦尔巴中部的冰川自 1900 年左右的小冰河时代最大值以来一直在消退。过去冰川的面积范围可以根据末端冰碛位置可靠地重建。然而，冰川厚度和体积的重建仍然相对更加复杂和不确定。在这项研究中，基于运动结构技术和现场 dGPS 测量，结合 1908 年的历史照片和 1938 年的航空照片分析，重建了费迪南德冰川过去的厚度和体积变化。和最近的照片，1908 年冰川前沿高度估计为 50 m，冰川体积为 9150 万立方米，1938 年冰川体积估计为 7610 万立方米，而 2014 年为 629 万立方米。这意味着自 1938 年以来体积减少了 90% 以上。20 世纪上半叶冰川的融化导致冰川表面变薄和降低，同时大量的冰量损失，而面积范围几乎没有受到影响。考虑到 2014 年的平均冰层厚度以及持续的气候变暖，费迪南德冰川很可能在未来 30 年内完全消失。