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Morphological and ice-dynamical changes on the Tasman Glacier, New Zealand, 1990–2007
- Source :
-
Global & Planetary Change . Aug2009, Vol. 68 Issue 3, p185-197. 13p. - Publication Year :
- 2009
-
Abstract
- Abstract: This paper presents data concerning recent (1990–2007) surface morphological and ice-dynamical changes on the Tasman Glacier, New Zealand. We use remote-sensing data to derive rates of lake growth, glacier velocities and rates of glacier surface lowering. Between 1990 and 2007, the glacier terminus receded ~3.5 km and a large ice-contact proglacial lake developed behind the outwash head. By 2007 the lake area was ~6 km2 and had replaced the majority of the lowermost 4 km of the glacier tongue. There is evidence that lake growth is proceeding at increasing rates — the lake area doubled between 2000 and 2007 alone. Measured horizontal glacier velocities decline from 150 m a−1 in the upper glacier catchment to almost zero at the glacier terminus and there is a consequent down-glacier increase in surface debris cover. Surface debris mapping shows that a large catastrophic rockfall onto the glacier surface in 1991 is still evident as a series of arcuate debris ridges below the Hochstetter icefall. Calculated glacier surface lowering is most clearly pronounced around the terminal area of the glacier tongue, with down-wasting rates of 4.2±1.4 m a−1 in areas adjacent to the lateral moraine ridges outside of the current lake extent. Surface lowering rates of approximately 1.9±1.4 m a−1 are common in the upper areas of the glacier. Calculations of future lake expansion are dependent on accurate bathymetric and bed topography surveys, but published data indicate that a further 8–10 km of the glacier is susceptible to calving and further lake development in the future. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09218181
- Volume :
- 68
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Global & Planetary Change
- Publication Type :
- Academic Journal
- Accession number :
- 43615915
- Full Text :
- https://doi.org/10.1016/j.gloplacha.2009.05.003