March 29, 2012
Petain Glacier Retreat, Alberta
Posted by Mauri Pelto
Petain Glacier’s meltwater feeds Petain Creek and then Upper Elk Lake in . The glacier like the vast majority in Alberta has been losing area and volume during its retreat.
Bolch et al (2010) noted that the glaciers in western Canada had on average lost 11% of their area from 1985 to 2005, 16% on the east slope of the continental divide in the Rocky Mountains of Alberta. As the glaciers retreat their meltwater that is primarily yielded in late summer when other sources are at a minimum is declining. It is anticipated that during this century glacier contributions to streamflow in Alberta will decline from 1.1 km3 a−1 in the early 2000s to 0.1 km3 a−1 by the end of this century Marshall et al (2011). Petain Glacier has a well defined moraine established during the Little Ice Age, green line. Retreat is examined by comparison of Google earth Imagery in 2005 and 2010 and Landsat imagery from 1994 and 2009. By 1994 the glacier had retreated 850 meters from the Little Ice Age moraine, and 900 meters by 2005 (orange line) and 930 meters by 2009. .
The retreat rate has been 4 meters/year recently. The retreat will continue as the blue arrows indicate locations where the glacier is thinning and exposing new areas of rock upglacier of the terminus. The red arrows indicate small lakes beyond the glacier terminus. The 2005 and 2010 images from Google Earth are tilted and indicate a 30 m retreat in the 5 years. In the image of the terminus below the blue arrow indicates the terminus the yellow arrows collapse features near the terminus indicating stagnation, the light green arrow indicates the thin debris covered area with surface stream channels again indicating stagnant conditions and retreat that will continue.