On the east margin of the Juneau Icefield is a small, compared to other glaciers, 7 km long unnamed valley glacier, here identified as West Hoboe Glacier. Here we use Landsat imagery to identify changes from 1984 to 2013. This glacier is just east of the retreating Hoboe Glacier and Llewellyn Glacier. The glacier flows from 2000 m down to 1250 m and drains into Atlin Lake at the headwaters of the Yukon River. In 2014 the Juneau Icefield research Program is planning to complete field measurements on this glacier for the first time.
Google Earth Image
West Hoboe Glacier is in background of image from the Toby Dittrich led expedition to Mount Service in 2013.
In 1984 West Hoboe Glacier ended at the red arrow below a small cirque glacier south of the glacier. In each image the arrow and letters are in the same location, the pink arrow indicates the 2013 terminus position. Point A indicates a small ice filled basin connected to the West Hoboe Glacier in 1984. The green arrow indicates the junction of the two main arms of the glacier, which has a width of 1100 m. Point B and C are bedrock outcrops in the upper portion of the glacier. By 1993 the glacier has retreated a short distance from the 1984 terminus position, red arrow. By 2004 the glacier has continued to retreat from the 1984 position, red arrow, the tributary glacier junction, green arrow, has been reduced to 900 m. At Point A there is no longer ice in the basin. At Point B the bedrock outcrop exposure has expanded. Both indicate glacier thinning. In 2004 and 2009 snowcover is limited on the glacier. In 2013 a pair of Landsat images, August 1, 2013 and September 2, 2013 indicate that the glacier has retreated 850 m from 1984-2013, now ending at the base of a narrow landslide prone gully. The connection at the green arrow is 800 m, a 300 m reduction in width since 1984. The thinning of the glacier has led to bedrock expansion at Point B and C, this is a 12% reduction in total length. At Point A the separation between the basin and the glacier indicates both marginal retreat and thinning of the glacier. Notice that 70% of the glacier in early September has lost its snowcover. The thinning even at the top of this glacier indicates it will not survive current climate.
1984 Landsat image
1993 Landsat image
2004 Landsat image
2009 Landsat image
8-1-2013 Landsat image