January 31, 2015

Southwest Brazeau Icefield Retreat, Alberta

Posted by Mauri Pelto

The Brazeau Icefield straddles high peaks southeast of Jasper, Alberta.  The northern outlet glaciers drain into Maligne Lake and the southern outlet glaciers drain in to Brazeau Lake and the Brazeau River.  The Brazeau River flows into Brazeau Reservoir a 355 MW hydropower facility, before joining the Saskatchewan River. An inventory of glaciers in the Canadian Rockies indicate area loss of 15% from 1985 to 2005 (Bolch et al, 2010).  The more famous Columbia Icefield to the west has lost 23 % of its area from 1919-2009 with ice loss at a minimum during the 1970’s (Tennant and Menounos, 2013). Here we examine an unnamed outlet glacier at the southwest corner of the Brazeau Icefield from 1995 to 2014 using Landsat imagery.

brazeau Icefield map

In 1995 the glacier terminated at the red arrow and was 1900 m long, orange dots mark the upper boundary.  The glacier had limited retained snowpack in 1995.  The poor clarity is do to forest fire smoke in the region.  In 1998 the proglacial lake where the glacier terminates is much clearer, snowpack is again limited, but more extensive than in 1995.  In 2002 retreat is evident as the lake is expanding as the glacier retreats.  The glacier still ends in the lake and still has limited snowcover.  In 2013 the glacier has retreated completely from the lake and snowcover is again limited.  The lack of snowcover is persistent in the satellite images which are typically not from the end of the melt season, hence even more snowcover will be lost.  Lack of a significant persistent snowcover area indicates a glacier that will not survive (Pelto, 2010). In 2014 the area experienced considerable forest fires, which leads to poor image clarity.  The glacier terminus is now significantly separated from the lake and terminates at the yellow arrow.  The distance from the yellow to the red arrow represents a 350-400 m retreat in 20 years.  The glacier has lost 20% of its length in this period.  This retreat is similar to that of Fraser Glacier and more significant given the small size of the glacier than for Saskcatchewan Glacier

brazeau icefield 1995

1995 Landsat image

brazeau icefield 1998

1998 Landsat image

brazeau sw 2002

2002 Landsat image

braeau sw 2013

2013 Landsat image

brazeau sw 2014

2014 Landsat image