Glacier recession reduced for 2006-07
Thanksgiving weekend was a wet and blustery blow for our 33 rd annual survey of Wedgemount Glacier, but it was a special occasion nonetheless.
The founder of the project, William A. Tupper, passed away in 2005. His son Robbie, BCLS engineering surveyor, motored from his home and office at Vernon to officially take over the leadership of the annual survey. With him came an arsenal of new monitoring methodologies.
Coming along as well was one of Robbie Tupper’s school day chums, David Lyon, whose father had also been instrumental in helping out with the annual survey in the 1970s and 1980s.
Saturday was a cool day obscured by several layers of clouds as we trudged on 20-30 cm of new snow up to the cabin overlooking the lake. The weather was not at all promising on arrival; we hurried to the snout of the glacier, assisted by another lone voyager who, with his snowshoes, broke trail to the east end of the lake. Two hundred metres beyond shore edge lies the snout of the glacier covered in new snow. In 1991 the glacier edge had stood at shore edge.
Arriving at the toe of the glacier, one shoveled off the snow to find its exact edge while others uncovered the nearby baseline markers established in 2006, from which the offset to 2007 was tape-measured to a lowly 2.5 metres of recession, the lowest value of recession registered since 1998-99 when it was only 1.6 metres. Jubilation reigned; from (–)15.6 metres recession in 2004-05, to (–)11.1 for 2005-06, and now only (–)2.5 metres for this past year it was what we were hoping to find.
Yes, the slow melt season of this year may have played a role in the reduced recession, but it is the arrival of a “kinematic wave” from the record snowfall of 1998-99, racing from the upper glacier to the snout, but by now transformed to dense firn and ice, which generated an extraordinary advance of glacier over the winter and following months. The marker placed at the toe of the glacier in 2006 was gone (overridden or shoved aside). That is, over the winter and spring the glacier had advanced downslope of the 2006 position and over this past summer had retreated to just upslope of the previous position. Is this the end of the arrival of the “wave”, or will it continue for another year and provide a season ending advance in 2008? The only measured previous advance was in 1980-81, although the El Niño year of 1983-84 served up a “standstill”.
After a horrendous overnight windstorm, followed by a very wet and turbulent Sunday, the crew leaned into the wind and rain to visit William Tupper’s key survey station above the cabin. After setting a permanent bronze B.C. Legal Survey monument, labelled “W.A.T. – 6” and now registered with the provincial government, son Robbie scattered his father’s ashes around the base of the adjacent survey cabin, built by William over 30 years ago. Soon after, a very sloppy and wet descent to the new park trailhead concluded the mission.
Earlier in September the Overlord Glacier Survey was carried out in fine weather. Upon arrival on the crest of the moraine overlooking the glacier’s bi-lobed snout, seven goats were seen frolicking in the adjacent mud and dust baths. They scurried up glacier upon recognizing my presence.
The survey in 2006 measured 11.2 metres of recession on the left hand lobe and 18.2 metres on the then almost non-existent right hand lobe, or an average 14.7 metres of recession, down slightly from the average of 16.65 metres for 2003-04 and for 2004-05. A surprise was in store: the right hand lobe was again fully developed, showing only 5.0 metres of additional recession. The left hand lobe also had a reduced recession, 9.8 metres, and the two averaged together is (–)7.4 metres, or roughly half the loss of the previous year. So, the resurging right hand lobe suggests that the 1998-99 extraordinary snow year is now on its way as a wave to the snout of the glacier, but again this past year’s heavy snowfall and cool summer likely had a hand in slowing the recession as well.
Climate cooling (?) or is climate warming being over-printed by other natural variations in oceanic climate? It’s premature to draw conclusions but the cool oceanic currents of La Nada are on its way for this winter. The end is not so near for “our” glaciers Mr. Gore!
Written by: Karl Ricker