Changes in the geometry and volume of rabots glaciär, sweden, 2003–2011: recent accelerated volume loss linked to more negative summer balances

Abstract

Terminus geometry, ice margins, and surface elevations on abots glaciär were measured using differential during summer 2011 and compared with those similarly measured in 2003. Glacier length over the eight years decreased by ∼105 m corresponding to 13 m a⁻¹, a rate consistent with ice recession over the last several decades. Measured changes in surface elevations show that between 2003 and 2011 the glacier's volume decreased by ∼27.6 ± 2.6 × 10⁶ m³, or 3.5 ± 0.3 × 10⁶ m³ a⁻¹. This compares favorably with an estimate of −28.1 ± 2.6 × 10⁶ m³ based on a mass‐balance approach. The rate of volume loss appears, however, to have significantly increased after 2003, being substantially greater than rates determined for the intervals 1959–80, 1980–89, and 1989–2003. This increase corresponds to a sustained interval of more negative summer balances. Previous work suggests that as of 2003 abots glaciär had not yet completed its response to a ∼1°C warming that occurred c. 1900, and thus the current marked increase rate of ice loss might reflect the effect of recent, or accelerated regional warming that occurred during the last decade superimposed on its continued response to that earlier warming.

Key words:

• glacier
• climate
• mass balance
• dGPS
• Rabots glaciär
• northern Sweden

Acknowledgements

Special thanks go to personnel of the Tarfala Research Station, especially H. Törnberg, G. Rosqvist, P. Jansson, and R. Jensen for their continued support of the field program on Rabots glaciär. Peter Jansson generously provided new mass balance compilations for Storglaciären and Rabots glaciär necessary for the analyses presented here, and made useful comment on an earlier draft of this paper. Grants from the University of Minnesota's Undergraduate Research Opportunity Program, Office of International Programs, and Faculty Research Enhancement Funds provided funding for this work. Graham Baird and Sean Figg provided assistance and much welcomed camaraderie in the field. The comments of two anonymous reviewers helped to improve the manuscript, and the patience of the editor in accommodating the delay in manuscript revision is greatly appreciated.

Additional information

Notes on contributors

Keith A. Brugger

Keith A. Brugger, Geology Discipline, University of Minnesota, 600 E 4^th Street, Morris, MN 56267, USA

Email: [email protected]

Latysha Pankratz

Latysha Pankratz, Geology Discipline, University of Minnesota, 600 E 4th Street, Morris, MN 56267, USA; Present address: Permitting and Compliance Division Montana Department of Environmental Quality 1520 E. Sixth Avenue Helena, MT 59620, USA

Email: [email protected]