February 26, 2010
Waputik Icefield Outlet Glacier retreat, Alberta Canada
Posted by Mauri Pelto
The Waputik Icefield, near the Icefields Parkway, north of Banff, Alberta straddles the continental divide. The Waputik outlet “Liiliput” Glacier is a 3 kilometer long outlet draining east into Hector Lake and the Bow River. This glacier drains the north side of Lilliput Mountain, and is just southeast of Balfour Glacier, which it merged with in the late 19th century. That is why the glacier lacks a proper name, it was part of the Balfour Glacier when named. The Lilliput Glacier has retreated 2.3 km from its maximum. The Balfour Glacier with which it was joined retreated at a rate of 10 meters per year at the end of the 19th century and 40 meters per year up to 1945, by 1945 the glaciers had separated (Ommaney, 2000). From 1945 to 1970 limited retreat occurred on either Lilliput or Balfour Glacier.
This Lilliput Glacier is now continuing to retreat, 320 meters since the 1970 picture of the glacier was taken. In 1970 the glacier still has a single terminus in the valley and ended a short distance above a steep bedrock slope. By 1994 the glacier has developed two termini and has retreated 200 m from the 1970 position. The 2002 terminus in this Google Earth image has retreated an additional 100-200 meters depending on location along the front. A closeup of the terminus area indicates limited crevassing, indicating limited movement and continued retreat. The supraglacial stream (winding stream channel on glacier surface) that is visible has downcut a considerable channel, this too indicates limited movement. An active glacier terminus would closeup such a channel seasonally as movement continued and meltwater flow ceased. The glacier in 2002 still has an accumulation zone at the head of the glacier. For a glacier like this to be in equilibrium it needs at least 50% of its area to be snowcovered at the end of the summer, this percentage is the accumulation area ratio. In the image below the lines are annual accumulation horizons exposed in the glacier ice. This indicates a region of the glacier that is consistently exposed to ablation today. Only 40% of the glacier is snowcovered above this point. This indicates how little of the glacier is a consistent accumulation zone today. Without a consistent accumulation zone the glacier cannot survive.