The State and Evolution of Canada’s Glaciers
Activity Rationale
Canada's glaciers exist in diverse physiographic and climatic settings, from the cold, arid Canadian Arctic to the more temperate western Cordillera. The importance of Canada's glaciers with respect to sea-level rise and freshwater resources, while clear, is at present only partially quantified (with rudimentary data). Moreover, we are entering a time in our relationship with other nations when comprehensive knowledge of our freshwater assets and their vulnerability will be needed to protect and utilize them in a sustainable manner
Activity Leaders: Mike Demuth and David Burgess
The Topic
For glaciers in continental climates, summer conditions control mass balance (photo courtesy of Alexi Zwadzki). Larger image
Glaciers are enormous masses of terrestrial ice that form on certain land regions through the compaction and recrystallization of snow into ice. Because of the weight of this snow and ice, glaciers undergo readily observable deformation. The extent of a glacier is controlled by complex processes that act towards bringing into equilibrium its mass balance. In general, mass is redistributed outwards and towards lower elevations by flow and sliding. If more ice is melted away during the melt season than is supplied from the higher elevations (by flowing and sliding to lower elevations) then the glacier will appear to recede. Many glaciers have snouts that terminate in tidal waters or lakes. The calving away of this ice, forming icebergs, is another way a glacier can lose mass.
For high mass turn-over glaciers in humid coastal mountain ranges, winter conditions are also important (photo courtesy of Mike Demuth). Larger image
This is the situation facing many Canadian glaciers due to current warming trends. Increased rainfall, air temperature, and radiation flux result in increases in melting at the surface and increased runoff, although not all glaciers respond to specific climate changes in the same way and response times can be very long. However, the fluctuation of glaciers is an important issue because glaciers play a crucial role in both the global climate and the sea level. In addition, seasonal meltwater from glaciers is a resource of freshwater that is utilized for hydroelectric power generation, industry, the development of freshwater habitats, domestic water use, and irrigation. Glaciers act as water savings accounts, storing water during cool, wet climate and releasing it during warm, dry climate.
Glacier Measures and Metrics
To better assess the changing extent and nature of glaciers, single-site observations must be scaled up to the catchment and regional scales required for modeling climate change impacts. Data is needed that describes not only changes in glacier extent (length and area), but also in glacier mass balance, thickness, and flow regime. In addition, many hydrological modeling tools that use Earth Observation data require improvements in their treatment of glaciers and related hydrological phenomena.
The net accumulation (area A) of the glacier has a lower boundary called the equilibrium line (EL) where the net mass balance is zero. Below this line is the net ablation (area B). Mapping altitude of the EL and the relative proportion of area A to (area A + area B) are valuable indicators of glacier mass balance and climate change and can be performed over wide areas using remote sensing. Measurements of the flow of ice from A to B and the retreat of the glacier can also be performed using remote sensing. Note that the glacier may leave evidence of its former size in the form of end and lateral moraines and “trim lines” (artwork courtesy of the World Glacier Monitoring Service, Zürich).
Detailed information on how and where glaciers are being measured in Canada can be found here: Canada’s Glacier-Climate Observing System. With this system, this activity provides national co-ordination and international participation in data reporting and standards development for the specialized terrestrial networks of global climate observation programs such as WMO’s Global Climate Observing System (GCOS).
Impacts of the Recession of Canadian Glaciers
Glacier ice reservoirs in the Rocky Mountains of Alberta and BC’s Interior Ranges feed numerous reservoirs that produce hydro-power. The Bighorn hydro-electric plant and the Abraham Lake reservoir (top of image) were built in the 1970s on the main stem of the North Saskatchewan River. Studies conducted by the State and Evolution of Canada’s Glaciers team indicate that glaciers in this region have been reducing in area so quickly (since the mid-1950s) that, even under the relatively warmer climate of the last several decades, melt water contributions from glaciers are showing signs of decline. This Landsat 5 optical satellite image from 1998 depicts some of the vast reservoirs of ice that not everyone can see from the “Icefield Parkway” as they drive between Lake Louise and Jasper Alberta. The Columbia Icefield is visible at the upper left edge of the image. Larger image
There are a number of consequences that can result from the melting of glaciers. Over the short term, a warming climate causes streamflow increases due to increased melting. This may temporarily enhance power generation and freshwater supplies. In addition, a sustained intense warming may result in meltwater outbursts, rapid ice advances on to land or out to sea that can be dangerous and destructive. Over the long-term, high rates of melting and prolonged “mass wastage” will eventually exhaust the glacier resource and result in far-reaching consequences for communities that rely upon glacier meltwater for freshwater in the summer months. Interestingly, water management in Canada evolved during a period of relatively stable climate and a perception in some regions of abundant water. This was at least partly influenced by the once vast and iconic glaciers of the Canadian Rocky Mountains
Another potentially harmful impact of glacier decline is on the land surface albedo - the fraction of incident solar radiation that is reflected by the Earth's surface. This determines the amount of energy that is absorbed by the ground, and therefore the amount of energy that is available to evaporate water and to heat the ground and the lower atmosphere. Also, it plays a key role in the regulation of ecosystem energy, carbon and water processes that affect greenhouse gas exchange.
Glaciers and ice sheets have a high albedo over their accumulation zones, and the loss of the snow and firn usually found there will alter the optical characteristics of the Earth's surface; it will decrease the amount of overall surface reflection, resulting in greater absorption and atmospheric heating. Changes in the Earth's surface albedo are a useful indicator of firn pack loss and glacier retreat. In fact, the albedo of the glacier exerts a strong positive feedback effect on its own mass balance. The more glacier ice that is exposed as the snow and firn disappear, the lower the albedo, and the faster the glacier loses mass.
A measure that is useful in characterizing glacier change is the reduction in shortwave radiation albedo over mountains due to recent marked changes in the extent of perennial snow and ice; depletion of firn pack leads to earlier and increased exposure of darker glacier ice (e.g., Coast Mountains). Data courtesy Alex Trichtchenko. Larger image
Mass losses from glaciers result from the processes of sublimation, iceberg calving and melt. Iceberg calving and melt contribute to relative sea level rise - another harmful impact of glacier decline. Rising sea level has implications for low-lying coastal regions in mid-latitudes, in particular those where dense populations, high tidal ranges and proximity to the influence of tropical cyclones conspire to generate destructive storm surges. Canada’s coastlines are not immune to these effects, particularly where other elements of the cryosphere are also in decline. For instance, reductions in the generation of seasonal pack ice along our Arctic coast line in the autumn allow waves generated by storms to erode away valuable coastline upon which northern communities infrastructure depend.
While the majority of concern related to sea level rise lies with the future of the Earth’s two large ice sheets, the large glacier complexes of the Northwest Pacific region and the high Arctic Islands are contributing significantly to shorter-term increases. Quantifying these contributions has been based on relatively rudimentary mass balance data, extrapolated to give best estimates. More recently however, remote sensing has assisted in defining more confidently regional contributions from Canadian sources. Quantifying the contribution from iceberg calving is particularly difficult and remains a gap in our knowledge that researchers hope to fill by applying remote sensing over large regions where iceberg calving is significant.
One of the large tidewater glaciers emanating from the southeast region of the Devon Ice Cap, Nunavut. The calving ice front indicated by the arrow is approximately 9 km long. Much of the bed of the glacier shown in the above image is below sea level, making this huge area of ice potentially unstable should sea levels rise significantly and allow it to pick-up and float out to sea.
Results
This research will result in understanding and more completely defining water cycle balances in the high elevation and high latitude regions of Canada where a great deal of the future warming associated with climate change is calculated to take place. This work includes the great challenge of measuring the mass balance of the Earth's, and particularly Canada's, ice caps and glaciers for which there is currently no data, and constructing large scale land/ice mass budgets, as they concern sea level rise.
Another important aim of this Activity is to communicate geoscience information in order to inform policy and planning. Accepted geoscience research is used to inform government and community leaders, planners, and the public about the vulnerability of natural and human freshwater systems that may be adversely affected by future glacier variations.
For example, Activity staff and partners have characterized past-Century and recent glacier-climate and hydrological regime shifts occurring in the eastern slopes of the Canadian Rockies (Nelson Drainage Basin). Recognizing these and other shifts, and projected future changes, Alberta Environment has developed its Water for Life Strategy, which must adapt to upstream supply changes with evolving downstream demands for water.
The dark blue region defines the calculated discharge (m3/s) of the North Saskatchewan River at Whirlpool Point if glacier cover were completely absent. Note the prevalence of the modeled glacier contribution during the summer and autumn months during which the snowpack contribution decreases. The role of surface water- groundwater interaction in this region has received negligible attention but is considered important depending upon the intensity of the snow and ice meltwater generation.
Activity data and assessments of glacier-climate changes are also provided to the relevant national and international scientific assessment processes including those performed by the Intergovernmental Panel on Climate Change (IPCC) and through regular reporting on the status of Canada’s glaciers and their measurement to the United Nations Framework Convention on Climate Change.
Observational Evidence of Climate Change from the IPCC:
“…increased run-off and earlier spring peak discharge in many glacier- and snow-fed rivers [on all continents].”
Knowledge of Future Impacts from the IPCC:
“Water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by meltwater.”
Study Data
Information on the fluctuation of Canada’s glaciers and related research results produced by this Activity and its integrated program of monitoring and research can be obtained from the following:
- State and Evolution of Canada’s Glaciers - Canada’s Glacier-Climate Observing System
- World Glacier Monitoring Service
Links
Sensitivities to Climate Change in Canada – Western and Northern Alpine Regions
Glaciers and Ice Caps to Dominate Sea Level Rise through 21st Century
World Glacier Monitoring Service
Global Glacier Changes: Facts and Figures from the United Nations Environment Programme
Glaciers, Ice Sheets, and Climate Change from the Water Encyclopedia
Global Land Ice Measurements from Space
CFCAS (Canadian Foundation for Climate and Atmospheric Sciences) Western Canadian Cryosphere Network
International Association of Cryospheric Sciences
Publications
Please note that subscriptions may be required for access to some articles. To request a copy of publications, or for any more information, please contact Mike Demuth or David Burgess
Check for more recent publications in GEOSCAN, the publications database of the Geological Survey of Canada and the Canada Centre for Remote Sensing.
Boon, S., D.O. Burgess, R.M. Koerner, and M. J. Sharp (in-press). 47 years of research on the Devon Island Ice Cap, Arctic Canada. Arctic.
Mair, D., D.O. Burgess, M.J. Sharp, S. Marshall, F. Cawkwell, J. Dowdeswell and T. Benham (in-press). Mass balance of the Prince of Wales Icefield, Ellesmere Island, Nunavut, Canada. Journal of Geophysical Research.
Sauchyn, D., M.N. Demuth and A. Pietroniro (in-press). Upland watershed management and global change: Canada’s Rocky Mountains and western plains. In – Managing Water Resources in a Time of Global Change: Mountains, Valleys and Flood Plains. Alberto Garrido and Ariel Dinar Editors. Rosenberg Water Policy Forum, Volume 1, Henry Vaux Jr. Series Editor. Routledge.
Spence, C., S. Hamilton, P. Whitfield, M. Demuth, D. Harvey, D. Hutchinson, B. Davison, T.B.M.J. Ouarda, J.G. Deveau, H. Goertz, J.W. Pomeroy and P. Marsh. (in press). A framework for integrated research and monitoring (FIRM). Canadian Water Resources Journal.
Armenakis, C., F. Savopol, M.N. Demuth and A. Beaulieur. (in-press). Monitoring geospatial changes in Northern Canada using historical aerial photography and current remotely sensed data. International Polar Year GeoNorth 2007 Proceedings, August, Yellowknife, NWT.
Burgess, D.O., and Sharp, M. 2008. Recent changes in thickness of the Devon Island ice cap, Canada. Journal of Geophysical Research 113 (B07204): doi:10.1029/2007JB005238
Demuth, M.N., H.P. Marshall and E.M. Morris. 2008. High-resolution near-surface snow stratigraphy inferred from ground-based 8-18 GHz FMCW radar measurements: Devon Ice Cap, Nunavut, Canada 2005-06, CryoSat Validation Experiment. 64th Eastern Snow Conference Proceedings. May, St. John’s NFLD, p. 9-14.
World Glacier Monitoring Service/UNEP. 2008. Global Glacier Changes – Facts and Figures http://www.grid.unep.ch/glaciers/
World Glacier Monitoring Service. 2008. Fluctuations of Glaciers Volume IX, ICSU (FAGS) - IUGG (IACS) – UNEP – UNESCO - WMO.
Demuth, M.N. , V. Pinard, A. Pietroniro, B.H. Luckman, C. Hopkinson, P. Dornes and L. Comeau, 2008. Recent and past-century variations in the glacier resources of the Canadian Rocky Mountains - Nelson River System. Terra Glacialis Special Issue: Mountain Glaciers and Climate Changes of the Last Century: 27-52.
Fisher, D.A., E. Osterberg, A. Dyke, D. Dahl-Jesnsen, M.N. Demuth, C.M. Zdanowicz, J. Bourgeois, R.M. Koerner, P. Mayewski, C. Wake, K. Kreutz, E. Steig, J. Zheng, K. Yalcin, K. Goto-Azuma, B.H. Luckman, S. Rupper 2008. The Mt Logan Holocene-Late Wisconsinan isotope record: tropical Pacific-Yukon connections. The Holocene 18(5): 667-677.
Bell, C., D. Mair, D.O. Burgess, M.A. Sharp, M.N. Demuth, F. Cawkwell, R. Bingham and J. Wadham. 2007. Spatial and temporal variability in the snowpack of a high Arctic ice cap: implications for mass change measurements. Annals of Glaciology 48: 159-170.
Field, C.B., L.D. Mortsch,, M. Brklacich, D.L. Forbes, P. Kovacs, J.A. Patz, S.W. Running and M.J. Scott. 2007. North America. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 617-652. http://www.ipcc-wg2.org/index.html.
Marshall, S. J., M. J. Sharp, D.O. Burgess, and F. S. Anslow, 2007: Surface temperature lapse rate variability on the Prince of Wales Icefield, Ellesmere Island, Canada: Implications for regional-scale downscaling of temperature. International Journal of Climatology, 27, 385-398.
World Glacier Monitoring Service. 2007. Glacier Mass Balance Bulletin 9, ICSU (FAGS) - IUGG (IACS) – UNEP – UNESCO - WMO.
Hopkinson, C. and M.N. Demuth. 2006. Using airborne lidar to assess the influence of glacier downwasting on water resources in the Canadian Rocky Mountains. Canadian Journal of Remote Sensing 32(2): 212-222.
Demuth, M.N. 2006. Summary of advances in glacier observing and assessment 2000-2005. In – Canada's fourth national report on climate change: Actions to meet commitments under the United Nations Framework Convention on Climate Change. Environment Canada.
Pietroniro, A., M.N. Demuth, P. Dornes, J. Toyra, N. Kouwen, A. Bingeman, C. Hopkinson, D. Burn, and B. Brua, 2006. Streamflow shifts resulting from past and future glacier fluctuations in the eastern flowing basins of the Rocky Mountains. Final Report to the Alberta Government – Climate Change Resources Users Group and Alberta Environment. 202 pages + CD-ROM.
Wolfe, S., M.N. Demuth and G. Manson. 2006. Climate change impacts and adaptation in protected areas. Report on an ESS/Parks Canada workshop considering collaborative research and monitoring in National Parks.
Demuth, M.N., D.S. Munro and G.J. Young (Editors), 2006. Peyto Glacier: One Century of Science. National Hydryolog Research Institute Science Report #8, 278pp. (Cat No. En 36-513/8E; ISSN: 0843-9052; ISBN: 0-660-17683-1).
Demuth, M.N. and R. Keller, 2006. An assessment of the mass balance of Peyto Glacier (1966-1995) and its relation to recent and past-century climatic variability. In - Peyto Glacier: One Century of Science, M.N. Demuth, D.S. Munro and G.J. Young (editors). National Hydrology Research Institute Science Report 8: 83-132.
Holdsworth, G., M.N. Demuth and T.M.H. Beck, 2006. Radar measurements of ice thickness on Peyto Glacier, Alberta - Geophysical and Climatic Implications. In - Peyto Glacier: One Century of Science, M.N. Demuth, G.J. Young and D.S. Munro (editors). National Hydrology Research Institute 8: 59-79.
Presentations
Burgess, D.O. 2008. Climate clues from ice. Polar Continental Shelf 50th Anniversary, Roy Koerner Lecture Series – Out of the Cold, Museum of Civilization, Hull, Quebec.
Burgess, D.O. and M.N. Demuth 2008. State and Evolution of Canada’s Glaciers. Chilean-Canadian Workshop on Glaciological Collaborations, University of Ottawa.
Burgess, D.O., R.M. Koerner, M.N. Demuth, L. Gray, N. Short, and G.Cogley. 2008. Monitoring the mass balance of ice caps in the Canadian Arctic. Working Group on Arctic Glaciology meeting, Obergurgl, Austria
Burgess, D.O. 2008. Monitoring the mass balance of ice caps in the Canadian high Arctic. Korean-Canadian Polar Research Workshop, Polar Continental Shelf Project, Ottawa.
Demuth, M.N. and D. Haggarty. 2008. Glaciology and ecological integrity monitoring: Nahanni National Park Reserve. Parks Canada Agency, Northern Bioregion Annual Meeting. Winnipeg, Canada.
Demuth, M.N. 2008. Integrated snow, ice and water monitoring and research requirements for assessing socio-economic and ecosystem vulnerability in Canada’s mountain West. ERCC – Economic/Ecosystem Sectors Project (J33) Workshop. Ottawa, Canada.
Demuth, M.N. 2008. Calgary’s Water in a Changing Climate ? Look Upstream. City of Calgary Water Resources Workshop. Calgary, Canada.
St. George, S., M.N. Demuth and A.Pietroniro. 2008. Water, ice and timber: a geophyscial perspective on water resources in southern Alberta. CEATI Hydropower and Climate Change Conference. Montreal, Canada.
Gray. L., D.O. Burgess and M.N. Demuth. 2008. Arctic Change: Monitoring the Devon Ice Cap. Radarsat 2 Applications Workshop. Canadian Space Agency. Montreal, Canada.
Demuth, M.N. and D.O. Burgess. 2008. State and Evolution of Canada’s Glaciers – A National Glacier-Climate Observing System. Canadian Space Agency. Montreal, Canada.
Demuth, M.N. and D.O. Burgess. 2008. State and Evolution of Canada’s Glaciers – A model contribution to WMO’s future Global Cryosphere Watch initiative. Natural Resources Canada. Ottawa, Canada.
Burgess, D.O. + 16 others. 2007. Calibration and Validation of Cryosat: Experiments over the Devon Island ice cap, Canada, 2004-2006. CryoSat Workshop, European Space Agency, Noordwijk, Netherlands.
Demuth, M.N. 2007. Federal glaciology and CFCAS IP3 in the western and northern Cordillera. IP3 Annual Workshop. Waterloo, Canada.
Demuth, M.N., E.M. Morris, H-P. Marshall, D.O. Burgess, D.A. Fisher and R.M. Koerner. 2007. Characterizing glacier facies regime shifts on Devon Island Ice Cap, Nunavut, Canada. Canadian Geophysical Union. St. John’s, Canada.