Subglacial water storage and drainage beneath the Fennoscandian and Barents Sea ice sheets

QUATERNARY SCIENCE REVIEWS

卷:201

Article

Shackleton, Calvin¹  Patton, Henry¹  Hubbard, Alun^1,2  Winsborrow, Monica¹  Kingslake, Jonathan³  Esteves, Mariana¹  Andreassen, Karin¹  Greenwood, Sarah L.⁴ 

[1] UiT Arctic Univ Norway, CAGE Ctr Arctic Gas Hydrate Environm & Climate, Dept Geosci, N-9037 Tromso, Norway

[2] Aberystwyth Univ, Dept Geog & Earth Sci, Aberystwyth SY23 3DB, Dyfed, Wales

[3] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA

[4] Stockholm Univ, Dept Geol Sci, S-10691 Stockholm, Sweden

关键词: Subglacial lakes;    Basal hydrology;    Meltwater drainage;    Fennoscandian ice sheet;    Barents sea ice sheet;    Eurasian ice sheet complex;    Late weichselian;    Last glacial maximum;    Glacial geology;    Glaciation;   

DOI  :  10.1016/j.quascirev.2018.10.007

来源: Elsevier

【 摘 要 】

Subglacial hydrology modulates how ice sheets flow, respond to climate, and deliver meltwater, sediment and nutrients to proglacial and marine environments. Here, we investigate the development of subglacial lakes and drainage networks beneath the Fennoscandian and Barents Sea ice sheets over the Late Weichselian. Utilizing an established coupled climate/ice flow model, we calculate high-resolution, spatio-temporal changes in subglacial hydraulic potential from ice sheet build-up (similar to 37 ka BP) to complete deglaciation (similar to 10 ka BP). Our analysis predicts up to 3500 potential subglacial lakes, the largest of which was 658 km(2), and over 70% of which had surface areas <10 km(2), comparable with subglacial lake size distributions beneath the Antarctic Ice Sheet. Asynchronous evolution of the Fennoscandian Ice Sheet into the flatter relief of northeast Europe affected patterns of subglacial drainage, with up to 100 km(3) more water impounded within subglacial lakes during ice build-up compared to retreat. Furthermore, we observe frequent fill/drain cycles within clusters of subglacial lakes at the onset zones and margins of ice streams that would have affected their dynamics. Our results resonate with mapping of large subglacial channel networks indicative of high-discharge meltwater drainage through the Gulf of Bothnia and central Barents Sea. By tracking the migration of meltwater drainage outlets during deglaciation, we constrain locations most susceptible to focussed discharge, including the western continental shelf-break where subglacial sediment delivery led to the development of major trough mouth fans. Maps of hydraulic potential minima that persist throughout the Late Weichselian reveal potential sites for preserved subglacial lake sediments, thereby defining useful targets for further field investigation. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free