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Temporal variations in flow velocity at Finsterwalderbreen, a Svalbard surge-type glacier.
journal contribution
posted on 2008-08-21, 14:51 authored by Anne-Marie Nuttall, Richard HodgkinsRichard HodgkinsInter- and intra-annual velocity variations are well known on alpine glaciers, but their
importance for Arctic glaciers has only been recognized more recently. This paper presents flow velocity
data from Finsterwalderbreen, a 35km2 polythermal surge-type glacier in southern Svalbard that is
presently ~100 years into its quiescent phase. Field measurements of glacier surface velocities are
available from 1950–52 and 1994–97, and mean velocities for the last decade are estimated for the lower
glacier using cables drilled to the glacier bed. These velocities show substantial seasonal variations
indicating that basal sliding is an important component of surface velocities and interannual fluctuations
of up to 75%, possibly indicating variations in subglacial water storage. Several lines of evidence indicate
that this glacier has an extensive subglacial hydrological system, generally considered to be a
prerequisite for surge-type glaciers, which is at least partly pressurized. Information on surface
morphology from 1898 onwards shows that the glacier has experienced continuous retreat since the last
surge in about 1910, and has now retreated ~1.5km further back than its previous pre-surge position in
1898. Tracking of moraine loops on terrestrial and aerial photographs acquired over a 100 year period
indicates that the surge period of Finsterwalderbreen may be lengthening in response to climate changes.
History
School
- Social Sciences
Department
- Geography and Environment
Citation
NUTTALL, A.M. and HODGKINS, R., 2005. Temporal variations in flow velocity at Finsterwalderbreen, a Svalbard surge-type glacier. Annals of Glaciology, 42(1), pp. 71-76(6)Publisher
© International Glaciological SocietyPublication date
2005Notes
This article was published in the journal, Annals of Glaciology [© International Glaciological Society]. The definitive version is available at http://www.igsoc.org/annals/ISSN
0260-3055;1727-5644Language
- en