Toggle Main Menu Toggle Search

Open Access padlockePrints

Ice-dammed lateral lake and epishelf lake insights into Holocene dynamics of Marguerite Trough Ice Stream and George VI Ice Shelf, Alexander Island, Antarctic Peninsula

Lookup NU author(s): Professor Bethan DaviesORCiD

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

© 2017 The AuthorsWe present new data regarding the past dynamics of Marguerite Trough Ice Stream, George VI Ice Shelf and valley glaciers from Ablation Point Massif on Alexander Island, Antarctic Peninsula. This ice-free oasis preserves a geological record of ice stream lateral moraines, ice-dammed lakes, ice-shelf moraines and valley glacier moraines, which we dated using cosmogenic nuclide ages. We provide one of the first detailed sediment-landform assemblage descriptions of epishelf lake shorelines. Marguerite Trough Ice Stream imprinted lateral moraines against eastern Alexander Island at 120 m at Ablation Point Massif. During deglaciation, lateral lakes formed in the Ablation and Moutonnée valleys, dammed against the ice stream in George VI Sound. Exposure ages from boulders on these shorelines yielded ages of 13.9 to 9.7 ka. Following recession of the ice stream, George VI Ice Shelf formed in George VI Sound. An epishelf lake formed at 15–20 m asl in Ablation and Moutonnée valleys, dated from 9.4 to 4.6 ka, suggesting that the lake was stable and persistent for some 5000 years. Lake-level lowering occurred after this, with the lake level at 12 m at 3.1 ± 0.4 ka and at 5 m asl today. A readvance of the valley glaciers on Alexander Island at 4.4 ± 0.7 ka is recorded by valley glacier moraines overlying epishelf lake sediments. We speculate that the glacier readvance, which occurred during a period of warmth, may have been caused by a dynamic response of the glaciers to a lowering in surface elevation of George VI Ice Shelf.


Publication metadata

Author(s): Davies BJ, Hambrey MJ, Glasser NF, Holt T, Rodes A, Smellie JL, Carrivick JL, Blockley SPE

Publication type: Article

Publication status: Published

Journal: Quaternary Science Reviews

Year: 2017

Volume: 177

Pages: 189-219

Print publication date: 01/12/2017

Online publication date: 05/11/2017

Acceptance date: 12/10/2017

ISSN (print): 0277-3791

ISSN (electronic): 1873-457X

Publisher: Elsevier Ltd

URL: https://doi.org/10.1016/j.quascirev.2017.10.016

DOI: 10.1016/j.quascirev.2017.10.016


Altmetrics

Altmetrics provided by Altmetric


Share