January 8, 2011

White Glacier Retreat, Olympic Mts. Washington

Posted by Mauri Pelto

White Glacier descends the Northwest flank of Mount Olympus in Olympic National Park in Washington. The glacier had a very large retreat from its Little Ice age maximum to 1952 of 3200 meters (Heusser, 1957). At that time it was joined with its more famous neighbor Blue Glacier, which is also retreating today. From 1958-1980 the glacier advanced a small distance, the 1950 based map of the area shows the terminus location of the glacier at that point. The burnt orange line indicates the map terminus, the forest green line the 1990 terminus. The Blue Glacier advanced nearly 200 meters in this interval


USGS Topographic map

By 1990 the glacier had retreated 100 meters from its recent advance position. From 1990-2006 retreat accelerated averaging 12 meters per year, 315 meters total. By 2009 the glacier had retreated 420 m from the 1990 position and 520 meters from the map position. The Blue Glacier has retreated nearly the same distance, 300-325 meters since its maximum position in the 1980’s. In the image below from 2006 the retreat since 1990 is evident, what is also striking is the sections of the bedrock ridge between the two termini outlined that is emerging from the glacier, blue arrows. The White Glacier will become two distinct glaciers separated by this rock ridge as retreat continues. The retreat is ongoing as the lack of crevassing near the current terminus indicates. This is despite a fairly steep slope. The rock rib that is beginning to separate the White Glacier is also visible below. The terminus today is at 1400 m, the head of the glacier at 2000 m.

white glacier 1990
1990 Google Earth image
2006 Google Earth image
white glacier 2009
2009 Google Earth image

The high elevation of the upper glacier has allowed it to retain snowpack even in recent warm summers when other glaciers in the area, Anderson and Fairchild, lost all their snowcover. This will allow this glacier to endure current climate.

Heusser, C.J., 1957. Variations of Blue, Hoh and White Glaciers during recent centuries. Arctic, 10(3), 139-150.
Spicer, R.C., 1989. Recent variations of Blue Glacier, Olympic Mountains, Washington, USA. Arctic and Alpine Res., 21(1), 1-21.