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Lookup NU author(s): Professor Matt King
Changes in the volume and extent of land ice of the Svalbard archipelago have been the subject of considerable research since their sensitivity to changes in climate was first noted. However, the measurement of these changes is often necessarily based on point or profile measurements which may not be representative if extrapolated to a whole catchment or region. Combining high-resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's surface without the need for extrapolation. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard archipelago spanning 1961 to 2005. We find high variability in thinning rates between sites with prevalent elevation changes at all sites averaging -0.59 +/- 0.04ma(-1) between 1961-2005. Prior to 1990, ice surface elevation was changing at an average rate of -0.52 +/- 0.09ma(-1) which decreased to -0.76 +/- 0.10ma(-1) after 1990. Setting the elevation changes against the glaciers' altitude distribution reveals that significant increases in thinning rates are occurring most notably in the glaciers' upper reaches. We find that these changes are coincident with a decrease in winter precipitation at the Longyearbyen meteorological station and could reflect a decrease in albedo or dynamic response to lower accumulation. Further work is required to understand fully the causes of this increase in thinning rates in the glaciers' upper reaches. If on-going and occurring elsewhere in the archipelago, these changes will have a significant effect on the region's future mass balance. Our results highlight the importance of understanding the climatological context of geodetic mass balance measurements and demonstrate the difficulty of using index glaciers to represent regional changes in areas of strong climatological gradients.
Author(s): James TD, Murray T, Barrand NE, Sykes HJ, Fox AJ, King MA
Publication type: Article
Publication status: Published
Journal: Cryosphere
Year: 2012
Volume: 6
Issue: 6
Pages: 1369-1381
Print publication date: 01/01/2012
Date deposited: 13/02/2013
ISSN (print): 1994-0416
ISSN (electronic): 1994-0424
Publisher: Copernicus GmbH
URL: http://dx.doi.org/10.5194/tc-6-1369-2012
DOI: 10.5194/tc-6-1369-2012
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