Funding: Natural Environment Research Council (ARCICE thematic programme)

This collaborative research project, involving glaciologists from the University of Glasgow, Scotland and the University of Alberta, Canada, set out to investigate: (i) whether the structure of the subglacial drainage system at a 'typical' polythermal High Arctic glacier evolves during the course of a melt-season, (ii) if so, what mechanisms are responsible for such evolution, and (iii) whether such drainage system evolution impacts on spatial and temporal patterns of glacier dynamics.

This is a critical issue since links between hydrology and dynamics have been demonstrated to influence glacier melting at alpine glaciers by impacting on glacier profiles therefore mass balance. Since the High Arctic has been identified as especially sensitive to potential climatic warming, similar interactions may accelerate glacier melting in the High Arctic, inducing rising sea levels.

Fieldwork was undertaken from 1999-2001 at John Evans Glacier, a valley glacier situated on the east coast of Ellesmere Island in the Canadian High Arctic. A number of supraglacial streams drain into the englacial system via a crevasse field situated above a large bedrock obstacle. Dye-tracing experiments showed that streams draining into moulins in this location access the subglacial drainage system.

We wished to test whether the structure of the subglacial drainage system at John Evans Glacier evolved over the course of the short Arctic melt season from distributed to channelised drainage. Although this is a well recognised phenomenon for alpine glaciers, this hypothesis is as yet untested in glaciers with mostly-cold polythermal regimes. To test for drainage evolution, we used well-known dye-tracing techniques. Known quantities of the dye rhodamine WT were injected into certain moulins at certain times throughout the course of the melt season...

...With each injection, dye entered the englacial system, before passing into the subglacial system and then emerging in a stream draining from underneath the glacier snout. Water samples were collected at a gauging station placed in the emerging stream, and dye levels were determined by running these samples through a field fluorometer. The gauging station also contained a number of additional probes which measured stream conductivity, turbidity, water pressures and water temperatures. These variables can tell us important information concerning the properties of the subglacial drainage system in their own right; and they are also useful for interpreting the dye return curves.

Surface motion on John Evans Glacier was measured by drilling two networks of stakes into the glacier surface. One network, covering most of the lower glacier area, was monitored using standard geodimeter surveying techniques. The other network was more spatially extensive, and covered the whole length of John Evans Glacier, thus many of the stakes could not be monitored using standard surveying techniques. Instead, stake positions were measured periodically using differential GPS techniques. From these surveying programmes, we now have a record of exact stake positions all over John Evans Glacier for every two days of the 2000 and 2001 melt seasons.

Publications:

• Bingham, R.G.; A.L. Hubbard, P.W. Nienow and M.J. Sharp (2008) An investigation into the mechanisms controlling seasonal speedup events at a High Arctic glacier. Journal of Geophysical Research - Earth Surface, 113, F02006.
  [doi: 10.1029/2007JF000832].
  
  
• Bingham, R.G.; P.W. Nienow, M.J. Sharp and L. Copland (2006) Hydrology and dynamics of a polythermal (mostly cold) High Arctic glacier. Earth Surface Processes and Landforms, 31(12), 1436-1479.
  [doi: 10.1002/esp.1374].
  
  
• Bingham, R.G.; P.W. Nienow, M.J. Sharp and S. Boon (2005) Subglacial drainage processes at a High Arctic polythermal valley glacier. Journal of Glaciology, 51(172), 15-24. [doi: 10.3189/172756505781829520].
  
  
• Bingham, R.G.; P.W. Nienow and M.J. Sharp (2003) Intra-annual and intra-seasonal flow dynamics of a High Arctic polythermal valley glacier. Annals of Glaciology, 37, 181-188.
  [doi: 10.3189/172756403781815762].
  
  
• Copland, L.; M.J. Sharp, P.W. Nienow and R.G. Bingham (2003) The distribution of basal motion beneath a High Arctic polythermal glacier. Journal of Glaciology, 49(166), 407-414.
  [doi: 10.3189/172756503781830511].