Chandler, D. M., Wadham, J. L., Nienow, P. W., Doyle, S. H., Tedstone, A. J., Telling, J., Hawkings, J., Alcock, J. D., Linhoff, B., & Hubbard, A. (2021). Rapid development and persistence of efficient subglacial drainage under 900 m-thick ice in Greenland. Earth and Planetary Science Letters, 566, 116982. https://doi.org/10.1016/j.epsl.2021.116982
Rapid development and persistence of efficient subglacial drainage under 900 m-thick ice in Greenland
|Author:||Chandler, David M.1,2; Wadham, Jemma L.2,3; Nienow, Peter W.4;|
1NORCE Norwegian Research Centre and Bjerknes Centre for Climate Research, Bergen, Norway
2Bristol Glaciology Centre, University of Bristol, Bristol, UK
3CAGE -Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT the Arctic University of Norway, 9010, Tromsø, Norway
4Department of Geosciences, University of Edinburgh, Edinburgh, UK
5Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK
6Department of Geosciences, University of Fribourg, Fribourg, Switzerland
7School of Natural and Environmental Sciences, Newcastle University, Newcastle, UK
8National High Magnetic Field Laboratory Geochemistry Group and the Department of Earth, Ocean and Atmospheric Sciences, Florida State University, USA
9German Research Centre for Geosciences GFZ, Potsdam, Germany
10US Geological Survey, New Mexico Water Science Center, Albuquerque, NM, USA
11Kvantum Institute, University of Oulu, 90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 2 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2021060132643
|Publish Date:|| 2021-06-01
Intensive study of the Greenland Ice Sheet’s (GrIS) subglacial drainage has been motivated by its importance for ice dynamics and for nutrient/sediment export to coastal ecosystems. This has revealed consistent seasonal development of efficient subglacial drainage in the lower ablation area. While some hydrological models show qualitative agreement with field data, conflicting evidence (both field- and model-based) maintains uncertainty in the extent and rate of efficient drainage development under thick (∼1 km) ice. Here, we present the first simultaneous time series of directly-observed subglacial drainage evolution, supraglacial hydrology and ice dynamics over 11 weeks in a large GrIS catchment. We demonstrate development of a fast/efficient subglacial drainage system extending from the margin to beneath ice >900 m thick, which then persisted with little response to highly variable moulin inputs including extreme melt events and extended periods (2 weeks) of low melt input. This efficient system evolved within ∼3 weeks at a moulin initiated when a fracture intersected a supraglacial river (rather than hydrofracture and lake drainage). Ice flow response to surface melt inputs at this site follows a pattern commonly observed in the lower GrIS ablation area, and by assuming a strong relationship between ice dynamics and subglacial hydrology, we infer that efficient subglacial drainage evolution is widespread under 900 m-thick ice in west Greenland. This time series of tracer transit characteristics through a developing and then persistent efficient drainage system provides a unique data set with which to validate and constrain existing numerical drainage system models, extending their capability for simulating drainage system evolution under current and future conditions.
Earth and planetary science letters
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
The project was funded by UK NERC grant nos. NE/H023879/1 (JW), NE/F021380/1 (PN) and NE/G005796/1 (AH). JW acknowledges support via a Royal Society Wolfson Merit Award and a Leverhulme Trust Research Grant (RPG-2016-439) and fellowship. AH gratefully acknowledges support by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223259 and an Academy of Finland ArcI visiting fellowship to the University of Oulu.
© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).