February 4, 2013

Lower Curtis Glacier Annual Survey 1984-2012

Posted by Mauri Pelto

The Lower Curtis Glacier is an avalanche fed cirque glacier on Mount Shuksan in the North Cascades of Washington. It is a south facing and low elevation glacier for the range. This is an unusual combination that is supported by the heavy accumulation via avalanching from the upper slopes of Mount Shuksan. The glacier displays a magnificent set of annual layers in its terminus tongue. The terminus tongue is a spectacular wall of seracs that quickly rises 55 m above the bedrock. There are typically 50 layers visible indicating that this most of the ice in the glacier is 50 years of less in age. The glacier advanced from 1950-1985 and has retreated 155 meters from 1987-2009 in the glacier center and 135 meters on average across the front. A longitudinal profile up the middle of the glacier indicates that it thinned 30 meters from 1908-1984 and 15 m from 1984-2012. Because of its heavy accumulation via avalanching the glacier moves rapidly and is quite crevassed at the terminus. Each year we survey the terminus location, measure the mass balance and survey the glacier surface elevation on a cross profile. The video is from footage taken in 2011 and 2012. The annual terminus photographs are from near Lake Ann, the 2003-2012 sequence represents the digital camera era. This coming summer will be our 30 consecutive summer on the glacier and we will see if it is the seventh consecutive summer of wet weather when we are there. [youtube=http://www.youtube.com/watch?v=xqpFlE_0syU]