气候变化领域集成服务门户(CCPortal): Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998-2019

CCPortal

DOI	10.5194/tc-15-1237-2021
	Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998-2019
	Kellerer-Pirklbauer A.; Avian M.; Benn D.I.; Bernsteiner F.; Krisch P.; Ziesler C.
发表日期	2021
ISSN	19940416
起始页码	1237
结束页码	1258
卷号	15 期号:3
英文摘要	Rapid growth of proglacial lakes in the current warming climate can pose significant outburst flood hazards, increase rates of ice mass loss, and alter the dynamic state of glaciers. We studied the nature and rate of proglacial lake evolution at Pasterze Glacier (Austria) in the period 1998 2019 using different remote-sensing (photogrammetry, laser scanning) and fieldwork-based (global navigation satellite system GNSS, time-lapse photography, geoelectrical resistivity tomography ERT, and bathymetry) data. Glacier thinning below the spillway level and glacier recession caused flooding of the glacier, initially forming a glacier-lateral to supraglacial lake with subaerial and subaquatic debriscovered dead-ice bodies. The observed lake size increase in 1998 2019 followed an exponential curve (1998 1900 m2, 2019 304 000 m2). ERT data from 2015 to 2019 revealed widespread existence of massive dead-ice bodies exceeding 25 m in thickness near the lake shore. Several large-scale and rapidly occurring buoyant calving events were detected in the 48 m deep basin by time-lapse photography, indicating that buoyant calving is a crucial process for the fast lake expansion. Estimations of the ice volume losses by buoyant calving and by subaerial ablation at a 0.35 km2large lake-proximal section of the glacier reveal comparable values for both processes (ca. 1 × 106 m3) for the period August 2018 to August 2019. We identified a sequence of processes: glacier recession into a basin and glacier thinning below the spillway level; glacio-fluvial sedimentation in the glacial proglacial transition zone covering dead ice; initial formation and accelerating enlargement of a glacier-lateral to supraglacial lake by ablation of glacier ice and debris-covered dead ice forming thermokarst features; increase in hydrostatic disequilibrium leading to destabilization of ice at the lake bottom or at the near-shore causing fracturing, tilting, disintegration, or emergence of new icebergs due to buoyant calving; and gradual melting of icebergs along with iceberg capsizing events. We conclude that buoyant calving, previously not reported from the European Alps, might play an important role at alpine glaciers in the future as many glaciers are expected to recede into valley or cirque overdeepenings. © 2021 EDP Sciences. All rights reserved.
英文关键词	cirque; climate change; disequilibrium; flooding; glacier; GNSS; iceberg calving; photography; proglacial environment; thermokarst; Alps; Austria; Carinthia; Pasterze Glacier
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202345
作者单位	Cascade - the Mountain Processes and Mountain Hazards Group, Institute of Geography and Regional Science, University of Graz, Graz, Austria; Department of Earth Observation, Zentralanstalt für Meteorologie und Geodynamik (ZAMG), Vienna, Austria; School of Geography and Sustainable Development, University of St Andrews, St Andrews, United Kingdom
推荐引用方式 GB/T 7714	Kellerer-Pirklbauer A.,Avian M.,Benn D.I.,et al. Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998-2019[J],2021,15(3).
APA	Kellerer-Pirklbauer A.,Avian M.,Benn D.I.,Bernsteiner F.,Krisch P.,&Ziesler C..(2021).Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998-2019.Cryosphere,15(3).
MLA	Kellerer-Pirklbauer A.,et al."Buoyant calving and ice-contact lake evolution at Pasterze Glacier (Austria) in the period 1998-2019".Cryosphere 15.3(2021).