September 5, 2013

Vowell Glacier Rapid Retreat, Bugaboos British Columbia

Posted by Mauri Pelto

Vowell Glacier is the largest glacier of the Bugaboo’s or maybe was. The glacier drains to the north into Vowell Creek has retreated quite rapidly from 1998 to 2013 creating a new lake and then retreating from that lake. Here we use a sequence of Landsat and Google Earth images to identify the changes from 1998 to 2013. In 1998 Landsat imagery shows the glacier to be 5.5 km long ending at 2060 m with no sign of a lake, this is also the size of the glacier in the BC 20,000 scale topographic map. vowell glacier overview
Vowell Glacier Google earth image from 2005 Pink line map-1998 terminus, green line 2005 terminus, yellow line 2012 terminus.
bugaboo map
Topographic map of Vowell Glacier

vowell glacier 1998 ls
Landsat image from 1998

The pink arrow in each image indicates the 1998 terminus and the yellow arrow the 2013 terminus. By 2005 Google earth imagery indicates a 800 m retreat from the map position and the formation of a proglacial lake with numerous icebergs and residual glacier pieces. The lower 500 m of the glacier is stagnant, uncrevassed and thin at this point. By 2012 Google Earth imagery indicates the glacier has retreated from the lake and is now 1500 m from the mapped position. The 2013 Landsat indicates a terminus retreat in 15 years of 1550 m. vowell glacier map overlay
Mapped extent of glacier overlain in Google Earth

vowell glacier 2005
2005 extent in Google Earth image

vowell map overlay
2012 extent in Google Earth image

vowell glacier terminus 2005
Close up of terminus in 2005

A wonderful image from Canadian Mountain Holidays Heli Ski Guide Lyle Grisedale shows the glacier in 2013. The yellow arrows indicate the current terminus, the burgundy arrows lateral moraines, red arrows glacier peices in the lake and the magenta arrow a detached portion of ice cored moraine.The glacier is flowing with some vigor through the icefall that extends from 2400 m to 2200 m. The lower 400 m of the glacier still appears stagnant and poised for retreat. Worse is the fact that the August 22nd image from 2013, with a month of melting to go, shows the snowline at 2600 m. The snowline will likely rise 200 m by the end of summer leaving only 25% of the glacier snowcovered. A glacier such as the Vowell would need about 60% snowcover to have an equilibrium mass balance for the year. This glacier is retreating more rapidly than the more famously named adjacent Bugaboo Glacier. CMH Bugaboos: Aug 25, 2013