Tuesday, December 3, 2013

Columbia Glacier, Monte Cristo Peak, North Cascades

The Columbia Glacier on Monte Cristo Peak (Location HERE) is listed in the Glacier Mass Balance Bulletin and includes some recent data. The data indicates that the glacier lost some mass in 2010 but gained mass in 2011. Overall the glacier has lost mass since measurements began in the late 1980s and the terminus retreated 15 meters from 1950 to 1979 and then 94 meters between 1979 and 2005. There is further information on the Columbia Glacier via http://www.nichols.edu/departments/glacier/columbiacirque.htm

As noted in the link the above the Columbia Glacier has some noteworthy features that can be further illustrated by looking at a topography map of the glacier and vicinity.

The Columbia Glacier is a low elevation glacier; the uppermost part of the glacier is at 5,600 feet. Further note that it faces south - the opposite one would expect for a large glacier. And further note that the cirque north of the ridge only has a small glacier even though it is facing north and presumably would be in a cooler location.

Why a large relatively low (compared to most other North Cascade glaciers) elevation glacier at this spot and not north of the ridge? As the post link above notes the Columbia Glacier's area of snow accumulation is enhanced due to avalanches of snow coming off of the high steep ridges above the glacier to the west, south and east. The smallish glacier to the north does not have that same snow gathering enhancement.

The presence of this large glacier is also aided by the western location of Monte Cristo Peak. Although just a bit over 7,000 feet, the western location enhances orthographic lift and associated heavier precipitation. And more wet weather systems approach from the southwest. Thus the combination of avalanches and orientation may overcome the more warm aspect of this glacier. One other bit of enhanced precipitation is the extension of the Puget Sound convergence zone often extends into this area of the Cascades.   

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