Ice Volume Estimates from Ground-Penetrating Radar Surveys, Wedel Jarlsberg Land Glaciers, Svalbard

Abstract

We present ground-penetrating radar (GPR)—based volume calculations, with associated error estimates, for eight glaciers on Wedel Jarlsberg Land, southwestern Spitsbergen, Svalbard, and compare them with those obtained from volume-area scaling relationships. The volume estimates are based upon GPR ice-thickness data collected during the period 2004–2013. The total area and volume of the ensemble are 502.91 ± 18.60 km² and 91.91 ± 3.12 km³, respectively. The individual areas, volumes, and average ice thickness lie within 0.37–140.99 km², 0.01–31.98 km³, and 28–227 m, respectively, with a maximum recorded ice thickness of 619 ± 13 m on Austre Torellbreen. To estimate the ice volume of unsurveyed tributary glaciers, we combine polynomial cross-sections with a function providing the best fit to the measured ice thickness along the center line of a collection of 22 surveyed tributaries. For the time-to-depth conversion of GPR data, we test the use of a glacierwide constant radio-wave velocity chosen on the basis of local or regional common midpoint measurements, versus the use of distinct velocities for the firn, cold ice, and temperate ice layers, concluding that the corresponding volume calculations agree with each other within their error bounds.

Acknowledgments

This research was supported by grant EUI2009-04096 (PolarCLIMATE-SvalGlac) from the Spanish EuroResearch Programme; grants CGL2005-05483, CTm²008-05878, and CTm²011-28980 from the Spanish National Plan for R&D; grant NCBiR/PolarCLIMATE-2009/2-2/2010 from the Polish National Centre for R&D; grants IPY/269/2006 and N N306 094939 from the Polish Ministry of Science and Higher Education; Polish-Norwegian funding through the AWAKE (PNRF-22-AI-1/07) project; and the ice2sea programme from the European Union 7th Framework Programme, grant number 226375, ice2sea contribution number 47. Satellite imagery used in this paper were available from ASTER © METI and NASA (2005), for August 2004 and July 2006, and from SPOT-5 © CNES (2008), for August 2008, distribution Spot Image S.A., all rights reserved. The paper was greatly improved by the comments and suggestions by Reinhard Drews and two anonymous reviewers. We also thank the associate editor, Jacob Clement Yde, for his efforts in improving the quality of the paper.