http://adaptation.nrcan.gc.ca/sensitivities/7_e.php

Climate Change Impacts and Adaptation

Sensitivities to Climate Change in Canada Western Alpine Regions

Alpine regions are those parts of the mountains that lie above the upper limit of continuous forest, or timberline. The exact nature of future climate changes in the mountains is not well known. However, we do expect that a general increase in temperature will bring about a northward movement of the timberline and a decrease in the extent of glaciers, icefields, winter snowpack and permafrost. Hazardous effects, such as glacier outburst floods and debris flows may accompany glacier recession. The reduction in the extent of alpine tundra, together with glacier recession, will bring about considerable modification of alpine scenery, with a possible impact on tourism. Changes in the winter snowpack will affect recreational skiing and the viability of many ski areas.

Map 7 larger image [GIF, 56.9 kb, 715 X 532, notice]

The most far-reaching result of predicted climate change in alpine areas is likely to be the effect of decreased snowpack and glacier ice on the discharge of the rivers that drain from the mountains. In western Canada, seasonal snowmelt and glacier melt are a major source of water for the rivers of the interior plains (shown on Map 7) and the dry southern interior of British Columbia. Decreased river discharge in summer may adversely affect water use for agriculture, hydro-electric generation, industry and domestic purposes.

Contact:

Mike Demuth June Ryder J.M. Ryder and Associates Terrain Analysis Inc. P.O.Box 45005 Dunbar, BC V6S 2M8 604-736-4211 Email: [email protected]

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Tracking the Melting Columbia Icefield

By Marisa Brennan Issue 50, August 2010

In this Issue

Tracking the Melting Columbia Icefield

Glaciologists at Natural Resources Canada conducts surveillance of the Columbia Icefield and studies the rates of its changes, the reasons for them and their impacts.

The Columbia Icefield rendered in 2000 by superimposing a Landsat image onto a digital elevation model derived from the Space Shuttle Radar. The yellow area is the approximate former extent of the icefield (c. 1840). The summit of the icefield, Snow Dome, is the hydrological apex of western North America, from which water flows into three oceans, the Pacific via the Columbia River, the Atlantic via the Nelson/Saskatchewan River system and the Arctic via the Mackenzie/Athabasca River system. Tourists standing in front of the Athabasca glacier between Alberta’s Lake Louise and Jasper usually notice that it’s receding. But what they might not see is that the Columbia Icefield — the massive icefield system that feeds it from above — is shrinking as well.

Glaciologists at Natural Resources Canada (NRCan) are looking to the Columbia Icefield to find out exactly how deep the ice is and how fast the ice is flowing.

“The life cycle of a glacier is not just about the melting of its lower reaches, but it’s also about its upper reaches, where it is nourished by snowfall,” says Michael Demuth, head of the glaciology section at NRCan’s Geological Survey of Canada (GSC) and project leader of The State and Evolution of Canada's Glaciers, part of a collaborative, nation-wide effort studying the impacts of climate change on Canada’s landmass. The project conducts surveillance of Canada’s glaciers and studies the rates of their changes, the reasons for them and their impacts.

Shrinking in a Changing Climate

As our climate changes, so does the nature of our water resources. The glacial melting rate has increased too significantly over the past 40 years, due partly to rising temperatures. “When it’s cool and wet, glacial ice builds up, storing water, which is released when it’s warm and dry,” Michael explains. “Some of these regions are heavily stressed from a water demand point of view.”

Michael Demuth and University of Calgary graduate student Jocelyn Hirose retrieve a shallow ice core to assess ice layers and the recent state of melting at Snow Dome, the summit of the icefield.

That’s why glacial monitoring is important: it will help us to better understand the current state of our glacial water resources so we can improve decisions made today and plan better for the future. Glaciers are a significant focus of interest, because they respond rapidly to climate change and their loss directly affects human populations and ecosystems. The consequences of a decrease in glacial mass through melting are considerable and include flooding, water shortages, sea-level rise and species loss.

Monitoring the Icefield

Did you know?

Radar glaciology was discovered by accident. During WW II, two pilots flying over Antarctica discovered that their radar altimeters were measuring through the ice, right down to the bottom of the ice sheet

The GSC glaciological team are setting out to measure the current thickness and volume of the Columbia Icefield in order to better predict what it will look like 10, 20 and 50 years from now. And they have a pretty good idea of what they might find.

“We’re expecting to be really surprised about how the thickness has changed,” says Michael. “From other assessments we conducted in western and northern Canada, you get the sense that glaciers are changing more rapidly now than 20 years ago. The data appears to support the impression of accelerated disappearance of glaciers in the Rocky Mountains.”

Digging out every six hours for four days takes patience, and was the major task of the later part of the Team's three-week expedition!

The team will use a radar system to sound the depth of the icefield. Although satellites and other remote sensing instruments can reveal much about the visible area of a glacier, radar scans can look beneath the surface and accurately determine various aspects of a glacier’s volume, such as how deep the ice is and how fast it’s flowing.

And this information will have wide-reaching and practical applications. “Our job is to help Canada and its citizens adapt to climate change, and the Columbia Icefield will make a significant contribution,” says Michael. “This knowledge will also be applied to other regions.”

The Columbia Icefield study will become part of the GSC’s glacier climate observing system, which evolved and is currently being operated under NRCan’s Climate Change Geoscience Program, in partnership with Parks Canada. The GSC will work together with NRCan’s Mapping Information Branch and the Canada Centre for Remote Sensing to develop state-of-the-art, ever-improving methods for measuring glaciers with remote sensing data.

More details on The State and Evolution of Canada’s Glaciers project can be found on the GSC Web site. For information on reproducing Natural Elements articles, please see our Important Notices.

Date Modified: 2010-09-10