Spatial distribution of erosion and deposition during a glacier surge: Bruarjokull, Iceland
Spatial distribution of erosion and deposition during a glacier surge: Bruarjokull, Iceland
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冰川涌动期间侵蚀和沉积的空间分布：冰岛布鲁阿冰原
DOI：
10.1016/j.geomorph.2015.09.010
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
K. Kjær
中科院分区：
文献类型：
--
作者：
N. Korsgaard;A. Schomacker;Í. Benediktsson;N. K. Larsen;Ó. Ingólfsson;K. Kjær
冰岛 Brúarjökull 涌动型冰川前场的时间序列数字高程模型 (DEM) 用于量化 1963-1964 年涌动所动员的物质体积。 DEM 是通过立体摄影测量法对浪潮之前（1961 年）和浪潮之后（1988 年和 2003 年）的航空照片生成的。该分析是在两个差异 DEM (DoD) 上进行的，即 1961-2003 年的 DoD 记录了涌动的影响，1988-2003 年的 DoD 记录了幼年涌动冰川陆地系统的涌动后修改。结合数字地貌图，国防部使我们能够量化激增对土地系统的影响（缩小到单个地貌）。由于最近的激增事件，在 30.7 平方公里的研究区域中总共动员了 34.2 ± 11.3 × 106 立方米的材料。其中，17.4±6.6×106m3的物质被侵蚀，16.8±4.7×106m3的物质沉积。超过一半的沉积体积是冰核地貌。这项研究表明，尽管总动员质量体积很高，但由于涌动而在前场沉积为地貌的冰和沉积物的净体积增益很低。此外，1963-1964 年激增造成的新死冰沉积占前场体积增量的 64%。 1988-2003 年国防部用于量化死冰的融化以及最近消融的布鲁阿冰原前场的其他冰川修饰。
Time-series of digital elevation models (DEMs) of the forefield of the Brúarjökull surge-type glacier in Iceland were used to quantify the volume of material that was mobilized by the 1963–1964 surge. The DEMs were produced by stereophotogrammetry on aerial photographs from before the surge (1961) and after (1988 and 2003). The analysis was performed on two DEMs of Difference (DoDs), i.e., a 1961–2003 DoD documenting the impact of the surge and a 1988–2003 DoD documenting the post-surge modification of the juvenile surging glacier landsystem. Combined with a digital geomorphological map, the DoDs allow us to quantify the impact of the surge on a landsystem scale down to individual landforms. A total of 34.2 ± 11.3 × 106m3of material was mobilized in the 30.7-km2study area as a result of the most recent surge event. Of these, 17.4 ± 6.6 × 106m3of the material were eroded and 16.8 ± 4.7 × 106m3were deposited. More than half of the deposited volume was ice-cored landforms. This study demonstrates that although the total mobilized mass volume is high, the net volume gain of ice and sediment deposited as landforms in the forefield caused by the surge is low. Furthermore, deposition of new dead-ice from the 1963–1964 surge constitutes as much as 64% of the volume gain in the forefield. The 1988–2003 DoD is used to quantify the melt-out of this dead-ice and other paraglacial modification of the recently deglaciated forefield of Brúarjökull.