当前位置: X-MOL 学术J. Glaciol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Characterization of subglacial marginal channels using 3-D analysis of high-density ground-penetrating radar data
Journal of Glaciology ( IF 2.8 ) Pub Date : 2021-03-18 , DOI: 10.1017/jog.2021.26
Pascal E. Egli , James Irving , Stuart N. Lane

Studying subglacial drainage networks is important for understanding the potential relationship between channel dynamics and rapid glacier recession as well as the role of subglacial channels in subglacial sediment evacuation. In order to delineate the planform geometry of snout marginal subglacial channels, densely spaced ground-penetrating radar (GPR) measurements at a frequency of ~70 MHz were carried out over the snout marginal zones of two temperate glaciers in the southwestern Swiss Alps, the Haut Glacier d'Arolla and the Glacier d'Otemma. Three-dimensional (3-D) data processing and amplitude analysis of the GPR reflection along the glacier bed was used to map the channels. At the Haut Glacier d'Arolla, two relatively straight channels of several meters in width were identified. The positions of these channels correspond well with the locations of channel outlets at the glacier terminus, as well as with fractures appearing on the glacier surface one month after the GPR data acquisition. The latter are believed to represent the beginning of ice collapse above the subglacial channels. At the Glacier d'Otemma, a major subglacial conduit was detected with similar dimensions to those identified at the Haut Glacier d'Arolla, but greater sinuosity. The position of this channel was confirmed by drone-based imagery acquired after glacier margin collapse. Our results confirm that high-density 3-D GPR surveys can be used to map subglacial channels near temperate alpine glacier margins.

中文翻译:

使用高密度探地雷达数据的 3-D 分析来表征冰下边缘通道

研究冰下排水网络对于了解通道动力学与冰川快速退缩之间的潜在关系以及冰下通道在冰下沉积物疏散中的作用非常重要。为了描绘冰河下通道边缘的平面几何形状,在瑞士阿尔卑斯山西南部的两个温带冰川的鼻子边缘区域上以约 70 MHz 的频率进行了密集间隔的探地雷达 (GPR) 测量,Haut Glacier d'Arolla 和 Glacier d'Otemma。沿冰川床的 GPR 反射的三维 (3-D) 数据处理和幅度分析用于绘制通道图。在 Haut Glacier d'Arolla,发现了两条相对笔直的、宽几米的通道。这些通道的位置与冰川终点通道出口的位置以及GPR数据采集1个月后冰川表面出现的裂缝位置相对应。后者被认为代表冰下通道上方冰崩的开始。在 Glacier d'Otemma,发现了一条主要的冰下管道,其尺寸与在 Haut Glacier d'Arolla 发现的相似,但弯曲度更大。该通道的位置由冰川边缘崩塌后获得的基于无人机的图像确认。我们的结果证实,高密度 3-D GPR 调查可用于绘制温带高山冰川边缘附近的冰下通道。以及在 GPR 数据采集一个月后,冰川表面出现裂缝。后者被认为代表冰下通道上方冰崩的开始。在 Glacier d'Otemma,发现了一条主要的冰下管道,其尺寸与在 Haut Glacier d'Arolla 发现的相似,但弯曲度更大。该通道的位置由冰川边缘崩塌后获得的基于无人机的图像确认。我们的结果证实,高密度 3-D GPR 调查可用于绘制温带高山冰川边缘附近的冰下通道。以及在 GPR 数据采集一个月后,冰川表面出现裂缝。后者被认为代表冰下通道上方冰崩的开始。在 Glacier d'Otemma,发现了一条主要的冰下管道,其尺寸与在 Haut Glacier d'Arolla 发现的相似,但弯曲度更大。该通道的位置由冰川边缘崩塌后获得的基于无人机的图像确认。我们的结果证实,高密度 3-D GPR 调查可用于绘制温带高山冰川边缘附近的冰下通道。发现了一条主要的冰下管道,其尺寸与在 Haut Glacier d'Arolla 发现的相似,但弯曲度更大。该通道的位置由冰川边缘崩塌后获得的基于无人机的图像确认。我们的结果证实,高密度 3-D GPR 调查可用于绘制温带高山冰川边缘附近的冰下通道。发现了一条主要的冰下管道,其尺寸与在 Haut Glacier d'Arolla 发现的相似,但弯曲度更大。该通道的位置由冰川边缘崩塌后获得的基于无人机的图像确认。我们的结果证实,高密度 3-D GPR 调查可用于绘制温带高山冰川边缘附近的冰下通道。
更新日期:2021-03-18
down
wechat
bug