By Karl Ricker
The annual surveys of Wedgemount and Overlord glaciers were completed in early September, yielding a few surprises. On Sept. 9 Carys Evans, Nina Evans-Locke, Dave Lyon and the writer ascended the Wedgemount Trail in the first rain event in over a month, arriving at the hut in a soggy state. The glacier survey on the following day was sunny, however, to provide very operable conditions.
On Sept. 14, Doug Wylie and the writer were not so fortunate — overnight snow down to the Flute Creek bridge crossing on the Singing Pass Trail, coupled with light snowfall and poor visibility throughout the day, allowed time for only a few basic measurements on the Overlord Glacier, but enough to provide a position on its snout for the conclusion of the melting season in 2006.
To confound those who were predicting that the very dry and hot summer would have devastating consequences on our glaciers, happily we can say that neither glacier produced any extraordinary recession. In 1990 Wedgemount Glacier began to retreat out of the lake basin to shore edge. Since then the glacier has receded about 200 metres away from the lake at an average rate of 12.4 metres/year; the annual rate was as low as 5.6 m in the record snowfall year of 1999, but as high as 20.3 metres in the near record warmth year of 1998. This year’s measurements (2005-06) were a below average 11.1 m, the lowest rate since 1999.
Survey of the Overlord Glacier this year provided a similar answer. While it had advanced 1.2 metres in the record snow pack year (1999), the overall recession rate has been 9.7 metres/year since 1990. The recession for 2006 was an above-average 11.2 metres (not 9.2 m as publicly proclaimed), though well below last year (16.7 m) and a couple of other years of higher values in the early 1990s.
The data might suggest that the extraordinary “bump” of snowpack of 1999 is just now beginning to reach the terminus of Wedgemount Glacier, hence defying the predicted heavy melt associated with a prolonged summer of warmth and sun. Yet, the “bump”, if it exists, has not yet reached the snout of Overlord. Next year’s surveys might reinforce this hypothesis, provided there is an average winter of snowfall followed by no unusual quirks during spring runoff.
Wildlife sightings on the two trips were also interesting. Four White-tailed ptarmigan were grazing, unconcerned, near the Wedgemount hut. A bear followed our morning footsteps in the snow for about one kilometre at Singing Pass, and goats have left recent signs of dust bathing near the snout of Overlord Glacier. Ducks (Barrow’s goldeneyes), were on both Russett and Wedgemount Lakes and there were a few song birds (American pipits and dippers) near the snout of each glacier. Every annual glacier survey produces a satisfying revelation.