Abstract
The transfer of surface-generated meltwater to the subglacial drainage system through full ice thickness crevassing may lead to accelerated glacier velocities, with implications for ice motion under future climatic scenarios. Accurate predictions of where surface meltwater accesses the ice/bed interface are therefore needed in fully coupled hydrodynamic ice-sheet models. We present a spatially distributed modelling routine for predicting the location and timing of delivery of surface-derived meltwater to the ice/bed interface through moulins and supraglacial lake drainage. The model is explained as it is applied to the Croker Bay glacial catchment of Devon Ice Cap, Canada. The formation of moulins, drainage of lakes, and the transfer of meltwater through the full ice thickness are modelled for the 2004 and 2006 ablation seasons. Through this case study we assess the model's sensitivity to degree-day factors, fracture toughness, tensile strength and crevasse width, and confirm that parameters influencing the rate at which water fills a crevasse are the most significant controls on the ability of a crevasse to reach the bed. Increased surface melt production, therefore, has the potential to significantly influence the spatial and temporal transfer of meltwater through surface-to-bed connections in a warmer climate.
| Original language | English |
|---|---|
| Pages (from-to) | 361-374 |
| Number of pages | 14 |
| Journal | Journal of Glaciology |
| Volume | 58 |
| Issue number | 208 |
| DOIs | |
| Publication status | Published - 2012 |
Cite this
Modelling the delivery of supraglacial meltwater to the ice/bed interface : application to southwest Devon Ice Cap, Nunavut, Canada. / Clason, Caroline; Mair, Douglas W. F.; Burgess, David O.; Nienow, Peter W.
In: Journal of Glaciology, Vol. 58, No. 208, 2012, p. 361-374.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Modelling the delivery of supraglacial meltwater to the ice/bed interface
T2 - application to southwest Devon Ice Cap, Nunavut, Canada
AU - Clason, Caroline
AU - Mair, Douglas W. F.
AU - Burgess, David O.
AU - Nienow, Peter W.
N1 - ACKNOWLEDGEMENTS We acknowledge the College of Physical Sciences, University of Aberdeen, for providing a graduate school studentship, and the Leverhulme Trust for awarding a Study Abroad Studentship, both to Caroline Clason. We thank Julian Dowdeswell for providing ice-thickness and surface-elevation data, and Martin Sharp for providing access to Devon Ice Cap data resources. We also thank Wolfgang Schwanghart for contributing his expertise, Gwenn Flowers and Mauro Werder for their invaluable input, and two anonymous reviewers whose comments improved the manuscript.
PY - 2012
Y1 - 2012
N2 - The transfer of surface-generated meltwater to the subglacial drainage system through full ice thickness crevassing may lead to accelerated glacier velocities, with implications for ice motion under future climatic scenarios. Accurate predictions of where surface meltwater accesses the ice/bed interface are therefore needed in fully coupled hydrodynamic ice-sheet models. We present a spatially distributed modelling routine for predicting the location and timing of delivery of surface-derived meltwater to the ice/bed interface through moulins and supraglacial lake drainage. The model is explained as it is applied to the Croker Bay glacial catchment of Devon Ice Cap, Canada. The formation of moulins, drainage of lakes, and the transfer of meltwater through the full ice thickness are modelled for the 2004 and 2006 ablation seasons. Through this case study we assess the model's sensitivity to degree-day factors, fracture toughness, tensile strength and crevasse width, and confirm that parameters influencing the rate at which water fills a crevasse are the most significant controls on the ability of a crevasse to reach the bed. Increased surface melt production, therefore, has the potential to significantly influence the spatial and temporal transfer of meltwater through surface-to-bed connections in a warmer climate.
AB - The transfer of surface-generated meltwater to the subglacial drainage system through full ice thickness crevassing may lead to accelerated glacier velocities, with implications for ice motion under future climatic scenarios. Accurate predictions of where surface meltwater accesses the ice/bed interface are therefore needed in fully coupled hydrodynamic ice-sheet models. We present a spatially distributed modelling routine for predicting the location and timing of delivery of surface-derived meltwater to the ice/bed interface through moulins and supraglacial lake drainage. The model is explained as it is applied to the Croker Bay glacial catchment of Devon Ice Cap, Canada. The formation of moulins, drainage of lakes, and the transfer of meltwater through the full ice thickness are modelled for the 2004 and 2006 ablation seasons. Through this case study we assess the model's sensitivity to degree-day factors, fracture toughness, tensile strength and crevasse width, and confirm that parameters influencing the rate at which water fills a crevasse are the most significant controls on the ability of a crevasse to reach the bed. Increased surface melt production, therefore, has the potential to significantly influence the spatial and temporal transfer of meltwater through surface-to-bed connections in a warmer climate.
U2 - 10.3189/2012JoG11J129
DO - 10.3189/2012JoG11J129
M3 - Article
VL - 58
SP - 361
EP - 374
JO - Journal of Glaciology
JF - Journal of Glaciology
SN - 0022-1430
IS - 208
ER -