Glacier Monitoring 2003: Local recession less than expected
Annual surveys of the positions of the termini (snouts) of Overlord and Wedgemount Glaciers were carried out on Aug. 10 and Sept. 21 respectively, melting some surprises. The warm summer of 2003 has had a lot of recent press, with the usual pronouncements that accelerated global warming, brought on by a variety of natural and man-induced forces, were causing havoc with glaciers, especially in the European Alps. So what are the main antagonists, locally, other than a forest fire heated atmosphere?
According to the climatologists and oceanographers, the Pacific Ocean is not one of the causes. The El Nino cycle was finished; equatorial ocean temperatures were near normal, if not beginning to shift to below the long-term average to a La Nina. That is, it was a neutral year or a La Nada. So the elevated atmospheric temperatures were forced by some other climatic factor. How did the glaciers fare in the face of this summer’s heat wave?
The surveys were interesting not only in view of the unusual summer on the one hand, but also with the observations of remarkable wildlife situations while carrying out the measurements.
The Overlord Glacier survey netted an average 1.4 metre recession only. The two snouts on the above photograph were measured. The snout in the centre, above the arrow, had actually advanced slightly (0.4 metres) compared to last year; whereas the wider snout on the right side of the photo had recessed 3.2 metres – the two together thus averaging a (-) 1.4 metre retraction.
The lobe of the glacier on the left-hand side of the photograph, however, underwent significant change. A small lake at its terminus in past years had drained due to the loss of an ice block or seal on the glacier bed.
More surprising however was the presence of 12 mountain goats at the snout of the glacier, rolling in the dust bowls on the recently exposed ground moraine. There were two kids among them and nanny goats were kept busy butting away yearlings that wandered too close to them. Over the summer the goats had stamped out a trail up and over the steep, sharp crested moraine from where the photo was taken. The local goat population appears to be increasing but probably not yet back to the historical herd size of 30 to 40 animals counted around Russet Lake and Fissile Mountain in 1965.
At Wedgemount Glacier the recession for the year was 14.3 metres, significantly more than Overlord, but less than the 18.1 metres of last year’s survey. The glacier is now about 147-150 metres away from the edge of the lake and 30 metres above it.
In 1991, the snout of the glacier had just receded from an aquatic position to lakeshore edge; hence the average recession since then has been almost 12.5 metres per year.
While measurements were underway, nine Barrow’s Goldeneye Ducks landed on the lake and began diving for food in what was perceived to be the most sterile of conditions. The area was completely covered by glacier in the 1970’s! This is the first time in 30 years of surveys that we have ever seen any waterfowl on the lake. While packing up, three or four American Dippers began searching for food underwater on the short creek draining the glacier to the lake. Mind boggling! Could there be any aquatic life in that cold torrent?
What have the surveys told us about the influence of a warm summer and the longer trends? Recession was greater last year in the tail-end of an El Nino. So the influence of a La Nada, coupled with an unusually stormy spring, have outweighed the influence of a prolonged heat wave.
In the longer trend however, Wedgemount Glacier is at an advanced recessed position. In 1951 the ice extended over the east one-third of the entire lake basin, receding about 714 metres to its current position, at the average rate of 13.7 metres/year. So, this year’s recession of 14.3 metres fits the overall trend.
On Overlord Glacier it is a different picture because it oscillates from year to year and in larger cycles. The glacier has not yet receded back to its most withdrawn position of 1951. Another 61 metres of retreat are needed to reach that historical point. Overlord appears to respond quite nicely to oceanic induced climatic events, whereas Wedgemount is not catching those moist and cool air masses. Why, I don’t know.
Friday, Oct. 17, 7:30 p.m. (doors open at 7 p.m.). Millennium Place- Mushrooms: Mysterious, Magical and Marvelous! A presentation by Sharmin Gamiet. Sharmin is a Mycologist and Consultant in Mycology Resources, and an expert on the biodiversity of mushrooms in British Columbia. Sharmin has also created a Web site on B.C. mushrooms that can be checked out at http://bcmushrooms.forrex.org Be prepared for a fascinating journey into the world of fungi. Suggested donation: $9 for non-members, $5 for members.
Saturday, Oct. 18, 9 a.m.-noon.Mushroom Walk (Fungal Foray). Meet at Spruce Grove Field House. Local Todd Bush and Friday night speaker Sharmin Gamiet will lead a nature walk focusing on fungi right here in Whistler. They will be identifying local mushroom species, what’s edible, what’s poisonous, and other fascinating mushroom facts. Kids are free. $5 for members, $10 for non-members.
Saturday, Oct. 18, noon-1 p.m. Cooking with mushrooms demonstration from local chef and mushroom enthusiast Ofra Buckmen. You will be able to sample cuisine creations using wild mushrooms and get direction on how to create wonderful mushroom dishes. $5 per person entitles you to a taster of fungi fare (free if you came on the walk).
Written by: Karl Ricker