DOI: 10.5194/tc-15-3731-2021
论文题名: Development of a subglacial lake monitored with radio-echo sounding: Case study from the eastern Skaftá cauldron in the Vatnajökull ice cap, Iceland
作者: Magnússon E. ; Pálsson F. ; Gudmundsson M.T. ; Högnadóttir T. ; Rossi C. ; Thorsteinsson T. ; Ófeigsson B.G. ; Sturkell E. ; Jóhannesson T.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 8 起始页码: 3731
结束页码: 3749
语种: 英语
英文摘要: We present repeated radio-echo sounding (RES, 5gMHz) on a profile grid over the eastern Skaftá cauldron (ESC) in Vatnajökull ice cap, Iceland. The ESC is a g1/4g3gkm wide and 50-150gm deep ice cauldron created and maintained by subglacial geothermal activity of g1/4g1gGW. Beneath the cauldron and 200-400gm thick ice, water accumulates in a subglacial lake and is released semi-regularly in jökulhlaups. The RES record consists of annual surveys conducted at the beginning of every summer during the period 2014-2020. Comparison of the RES surveys reveals variable lake area (0.5-4.1gkm2) and enables traced reflections from the lake roof to be distinguished from bedrock reflections. This allows construction of a digital elevation model (DEM) of the bedrock in the area, further constrained by two borehole measurements at the cauldron centre. It also allows creation of lake thickness maps and an estimate of lake volume at the time of each survey, which we compare with lowering patterns and released water volumes obtained from pre- and post-jökulhlaup surface DEMs. The estimated lake volume was 250gGL (gigalitresgCombining double low lineg106gm3) in June 2015, but 320g±g20gGL drained from the ESC in October 2015. In June 2018, RES profiles revealed a lake volume of 185gGL, while 220g±g30gGL were released in a jökulhlaup in August 2018. Considering the water accumulation over the periods between RES surveys and jökulhlaups, this indicates 10g%-20g% uncertainty in the RES-derived volumes at times when significant jökulhlaups may be expected. © 2021 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164746
Appears in Collections: 气候变化与战略
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作者单位: Institute of Earth Sciences, University of Iceland, Reykjavík, IS-102, Iceland; Remote Sensing Technology Institute, German Aerospace Center (DLR), Wessling, 82234, Germany; Icelandic Meteorological Office, Reykjavík, IS-105, Iceland; Department of Earth Sciences, University of Gothenburg, Box 460, Gothenburg, 405 30, Sweden
Recommended Citation:
Magnússon E.,Pálsson F.,Gudmundsson M.T.,et al. Development of a subglacial lake monitored with radio-echo sounding: Case study from the eastern Skaftá cauldron in the Vatnajökull ice cap, Iceland[J]. Cryosphere,2021-01-01,15(8)