Ice surface changes during recent glacial cycles along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica

QUATERNARY SCIENCE REVIEWS

卷:249

Article

Andersen, J. L.^1,2  Newall, J. C.^1,3,4  Blomdin, R.^3,4  Sams, S. E.¹  Fabel, D.⁵  Koester, A. J.¹  Lifton, N. A.^1,6  Fredin, O.^2,7  Caffee, M. W.^1,6  Glasser, Neil F.⁸  Rogozhina, I.⁷  Suganuma, Y.^9,10  Harbor, J. M.^1,3,4,11  Stroeven, A. P.^3,4 

[1] Purdue Univ, Dept Earth Atmospher & Planetary Sci, W Lafayette, IN 47907 USA

[2] Geol Survey Norway, Trondheim, Norway

[3] Stockholm Univ, Geomorphol & Glaciol, Dept Phys Geog, Stockholm, Sweden

[4] Stockholm Univ, Bolin Ctr Climate Res, Stockholm, Sweden

[5] Scottish Univ Environm Res Ctr, Glasgow, Lanark, Scotland

[6] Purdue Univ, Dept Phys & Astron, W Lafayette, IN 47907 USA

[7] Norwegian Univ Sci & Technol, Dept Geog, Trondheim, Norway

[8] Aberystwyth Univ, Ctr Glaciol, Dept Geog & Earth Sci, Aberystwyth, Dyfed, Wales

[9] Natl Inst Polar Res, Tachikawa, Tokyo, Japan

[10] Grad Univ Adv Studies SOKENDAI, Hayama, Kanagawa, Japan

[11] Purdue Univ Global, W Lafayette, IN USA

关键词: Antarctica;    Glaciation;    Quaternary;    Cosmogenic isotopes;    Dronning Maud Land;   

DOI  :  10.1016/j.quascirev.2020.106636

来源: Elsevier

【 摘 要 】

Reconstructing past ice-sheet surface changes is key to testing and improving ice-sheet models. Data constraining the past behaviour of the East Antarctic Ice Sheet are sparse, limiting our understanding of its response to past, present and future climate change. Here, we report the first cosmogenic multinuclide (Be-10, Al-26, Cl-36) data from bedrock and erratics on nunataks along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica. Spanning elevations between 741 and 2394 m above sea level, the samples have apparent exposure ages between 2 ka and 5 Ma. The highest-elevation bedrock sample indicates (near-) continuous minimum exposure since the Pliocene, with a low apparent erosion rate of 0.15 +/- 0.03 m Ma(-1), which is similar to results from eastern Dronning Maud Land. In contrast to studies in eastern Dronning Maud Land, however, our data show clear indications of a thicker-than-present ice sheet within the last glacial cycle, with a thinning of similar to 35-120 m during the Holocene (similar to 2-11 ka). Difficulties in separating suitable amounts of quartz from the often quartz-poor rock-types in the area, and cosmogenic nuclides inherited from exposure prior to the last deglaciation, prevented robust thinning estimates from elevational profiles. Nevertheless, the results clearly demonstrate ice-surface fluctuations of several hundred meters between the current grounding line and the edge of the polar plateau for the last glacial cycle, a constraint that should be considered in future ice-sheet model simulations. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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