Glacial geological studies of surge-type glaciers in Iceland — Research status and future challenges

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• 作者：Ó ; lafur Ingó ; lfsson^a ; ^b ; ^{olafuri@unis.no" class="auth_mail" title="E-mail the corresponding author} ; Í ; var Ö ; rn Benediktsson^b ; ^c ; Anders Schomacker^d ; ^e ; Kurt H. Kjæ ; r^e ; Skafti Brynjó ; lfsson^b ; ^d ; ^f ; Sverrir A. Jó ; nsson^b ; Niels Já ; kup Korsgaard^e ; Mark D. Johnson^g
• 关键词：Surge-type glacier ; Iceland ; Landsystem model ; Glaciotectonism ; Glacial geology
• 刊名：Earth Science Reviews
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：152
• 期：Complete
• 页码：37-69
• 全文大小：11345 K

文摘

Surging glaciers are potential analogues for land-terminating palaeo-ice streams and surging ice sheet lobes, and research on surge-type glaciers is important for understanding the causal mechanisms of modern and past ice sheet instabilities. The geomorphic signatures left by the Icelandic surge-type glaciers vary and range from glaciotectonic end moraines formed by folding and thrusting, crevasse-squeeze ridges, concertina eskers, drumlins and fluted forefields, to extensive dead-ice fields and even drift sheets where fast ice-flow indicators are largely missing. We outline some outstanding research questions and review case studies from the surge-type outlets of Brúarjökull, Eyjabakkajökull and Tungnaárjökull (Vatnajökull ice cap), Múlajökull and Sátujökull (Hofsjökull ice cap), Hagafellsjökull and Suðurjökull (Langjökull ice cap), Kaldalónsjökull, Leirufjarðarjökull and Reykjarfjarðarjökull (Drangajökull ice cap), as well as the surge-type cirque glaciers in northern Iceland. We review the current understanding of how rapid ice flow is sustained throughout the surge, the processes that control the development of the surge-type glacier landsystem and the geological evidence of surges found in sediments and landforms. We also examine if it is possible to reconstruct past surge flow rates from glacial landforms and sediments and scale-up present-day surge processes, landforms and landsystems as modern analogues to past ice streams. Finally, we also examine if there is a climate/mass-balance control on surge initiation, duration and frequency.