Proglacial lake expansion and glacier retreat in Arctic Sweden

ABSTRACT

Proglacial lakes have increased in number and extent in Arctic Sweden since the 1950s/1960s as glaciers have retreated dramatically. Interrogation of Rapid Eye imagery highlights that some lake terminating glaciers had substantial (>100 m) rates of retreat between 2010 and 2018, with one other land terminating glacier also retreating at a similar rate. However, analysis of a regional remote sensing time series suggests that proglacial lake formation in this period across the area has not been uniform. Despite glacier accumulation areas having similar maximum elevations (∼2,000 m) and similar alpine topography, proglacial lakes in the southern area (Sarek) were found to be significantly smaller than proglacial lakes in the northern area (Kebnekaise), which had smaller glaciers within corries and more prominent terminal moraines. Therefore, it cannot be assumed that proglacial lake formation will occur as glaciers retreat in response to elevated air temperature, particularly as only 33% of glaciers had proglacial lakes in their forefield. Thus, whilst it cannot be assumed that proglacial lakes will accommodate water currently held in glaciers, the 108 lakes mapped here present a substantial area (4.767 ± 0.377 km²) of fresh water that has not previously been included in the Global Lakes and Wetlands Database (GLWD). This inventory therefore provides an important dataset that can be used to underpin our understanding of the role of proglacial lakes within the hydrological system in this area of the Arctic.

KEYWORDS:

• Proglacial lake
• Arctic Sweden
• glacier retreat
• ASTER satellite

Acknowledgements

I would like to thank the NERC ACCE DTP scheme for funding and supporting the research, along with the project supervisors. Thanks to the freely available Global Lakes and Wetlands Database and ASTER imagery scenes that were downloaded from the Earthdata website (Earthdata. Available online: https://earthdata.nasa.gov/), as well as a data grant of TanDEMX World DEM. Thanks to both of the reviewers and many thanks to Nina Kirchner for extensive and detailed reviewer comments, which substantially improved the manuscript.

Data availability statement

Data is currently under embargo as part of PhD thesis on the White Rose repository. Embargo ends July 2022 and data will be uploaded to a repository after this.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Natural Environment Research Council under the ACCE Doctoral Training Programme.

Notes on contributors

Adrian Dye

Adrian Dye is a lecturer and researcher who is particularly interested in glacial and periglacial environments, remote sensing and GIS. His main research focuses on the thermal regime of proglacial lakes and the impact on glacier retreat rates.

Robert Bryant

Robert Bryant researches aeolian environments in many areas of the world through remote sensing and fieldwork, he is currently a Reader in Dryland Environments at the University of Sheffield.

David Rippin

David Rippin is a Senior Lecturer in Physical Geography at the University of York. David's research interests are focussed on the controls on the dynamics of glaciers and ice-sheets, and the use of ground-based and airborne radio-echo sounding (RES) techniques in exploring englacial and subglacial environments.