Observations of enhanced thinning in the upper reaches of Svalbard glaciers

• DOI: 10.5194/tc-6-1369-2012
• Publication Date: 2012-11-20T14:58:54Z
• Authors: T. D. James; T. Murray; N. E. Barrand; H. J. Sykes; A. J. Fox; M. A. King
• Keywords: Elevation (ballistics); Thinning; Archipelago; Glacier mass balance

Abstract. Changes in the volume and extent of land ice Svalbard archipelago have been subject considerable research since their sensitivity to changes climate was first noted. However, measurement these is often necessarily based on point or profile measurements which may not be representative if extrapolated a whole catchment region. Combining high-resolution elevation data from contemporary laser-altimetry surveys archived aerial photography makes it possible measure historical across glacier's surface without need for extrapolation. Here we present high spatial resolution time-series six Arctic glaciers spanning 1961 2005. We find variability thinning rates between sites with prevalent at all averaging −0.59 ± 0.04 m a−1 1961–2005. Prior 1990, changing an average rate −0.52 0.09 decreased −0.76 0.10 after 1990. Setting against glaciers' altitude distribution reveals that significant increases are occurring most notably upper reaches. coincident decrease winter precipitation Longyearbyen meteorological station could reflect albedo dynamic response lower accumulation. Further work required understand fully causes this increase If on-going elsewhere archipelago, will effect region's future mass balance. Our results highlight importance understanding climatological context geodetic balance demonstrate difficulty using index represent regional areas strong gradients.