Posts Tagged british columbia glacier melt

Nass Peak Glacier Retreat, Coast Mountains, British Columbia

“Nass Peak” Glacier is a 5 km long unnamed valley glacier that feeds Coast Mountain Creek and then Nass River. The closest community is Kitsault, BC on the north side of the small icefield from which the glacier originates. Nass peak map Here we examine changes in the is glacier in Landsat imagery from 1986 to 2013. In 1986 the glacier terminated at the red arrow, this is also approximately the mapped terminus position. The terminus is near the nose of a long ridge at 650 m in 1986. By 1997 the glacier had retreated 800 m to a location adjacent to the southern outlet stream from another glacier in a side valley. By 2010 the glacier has retreated behond the northern outlet stream of the side glacier, pink arrow and almost too the yellow arrow. In 2013 the glacier has retreated just beyond the yellow arrow a distance of 2000 meters since 1986 and is at an elevation of 850 m. For a glacier that was 7.5 km long and is now 5.5 km long that is a 27% loss of length in 27 years. The green arrow point to the separation between a side glacier and the Nass Peak Glacier, this expanded 250 m both from retreat of the side glacier and the lateral thinning at this elevation of Nass Peak Glacier. The last image is a 2009 Google Earth Image indicating the mapped terminus outline to the 2009 terminus.

The Nass Peak Glacier retreat is larger as a percentage of the glacier, but similar in distance than the nearby Porcupine Glacier, BC, Bromley Glacier, BC, Jacobsen Glacier, BC, Chickamin Glacier, AK and Patterson Glacier, AK. Nass Peak Glacier also has lacked a proglacial lake which typically enhances retreat via calving, making the retreat quite significant in terms of surface mass balance loss.
nass peak 1986
1986 Landsat Image

nass peak 1997
1997 Landsat Image

nass peak 2010
2010 Landsat Image

nass peak 2013
2013 Landsat Image

nass peak ge
2009 Google Earth Image

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Snowcap Creek Glacier Retreat, British Columbia

Snowcap Creek Glacier is one valley north of Stave Glacier in the Garibaldi Provincial Park Region of British Columbia. The retreat of glaciers in this region has been well documented by Koch et al (2009). The response varies from a glacier like the Helm Glacier which is melting away to the Snowcap Creek Glacier which is has been rapidly retreating but has remained vigorous.
snowcap creek 2006 ge
Landsat images and Google Earth images are used to document the development of a lake at the terminus of the glacier. In 1992 there is no lake at the main terminus, red arrow or subsidiary terminus at the yellow arrow. There is also a connection between the terminus and the glacier to the north at the magenta arrow. By 2009 there is a new lake at the main terminus that is 700 meters across the glacier reaches the western shore of this lake. A smaller lake has formed at subsidiary terminus, yellow arrow. The terminus is no longer connected to the glacier to the north at the magenta arrow. By 2012 the glacier has retreated 800 meters from 1992 and no longer reaches the western margin of the new unnamed lake, red arrow. The subsidiary terminus lake has expanded but is still less than 100 meters across.

snowcap creek glacier 1992
snowcap glacier 2009
snowcap creek glacier 2012

In each image the snowline is noted by a yellow-orange arrow, the glacier continues to have a persistent accumulation, which indicates it can survive current climate. A closer examination of the terminus in 2006 from Google Earth indicates the two new lakes, the detached ice remnant and active crevassing of the glacier surface close to the terminus. In 2006 the glacier terminus still reaches the newly formed lake. The active crevassing begins within 300 meters of the current terminus. The ice tongue reaching down to the lake has already retreated from it and this narrow tongue will be lost soon.
snowcap creek glacier terminus

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Spectacular Retreat of Melbern Glacier, British Columbia

The combined Melbern and Grand Pacific Glacier with a length of 55 km and width of 2-5 km, is a large valley glacier draining from the Saint Elias Mountains near the British Columbia-Alaska boundary. The glacier separates into two distinct glacier termini at Grand Pacific Pass. One of the tongues, Melbern Glacier, flows 20 km northwest ending in . Grand Pacific Glacier flows southeast to Tarr Inlet of Glacier Bay, just across the Alaska boundary. The Melbern Glacier turns north and ends in Lake Melbern. Lake Melbern began to form around 1979 as noted by Clague and Evans (1994). By 1986 the lake had expanded greatly as the former tributary to Melbern Glacier, Konamoxt Glacier had separated, and a 7km retreat of Melbern Glacier from the Konamoxt Glacier had ensued, first image from their paper. Clague and Evansin the second image further note that the ice dam of the Konamoxt Glacier that blocks Melbern Lake had broken by 1991 and the lake level had dropped. The retreat has continued unabated up through 2009. Here we use a series of Landsat images and one Google Earth Image to illustrate the retreat up to 2013. The first is a 1986 Landsat Image, K=Konamoxt and M=Melbern. In this image Konamoxt still blocks Melbern Lake and Melbern Glacier terminates adjacent to another tributary from the south, orange marks the 1986 terminus of both glaciers. The second image is a false color Landsat image from 2001. Konamoxt Glacier extends partly across the lake but not completely. The lake to the northwest of Konamoxt is filled with icebergs. Melbern Glacier has retreated 3 km since 1986. The third image is the Google Earth image also from 2001 showing the 1986 margin as well, in orange and the 2007 terminus in purple. The fourth image is from 2007, indicating a 1.5 km retreat of Melbern Glacier in the last six years. By 2013 the retreat is 2.25 km since 2001 and 5.25 km since 1986. Konamoxt Glacier no longer reaches Lake Melbern proper and is beginning a retreat up its own valley. The lake itself has changed color and lost its fleet of icebergs. The last image is from July 2013 and Lake Melbern is now 20 km long and still expanding. melbern glacier 2013
Melbern Glacier is following the same pattern as nearby Yakutat Glacier and Grand Plateau Glacier. The lower 3 km of the glacier appears stagnant. However, there is a moraine band 10m km above the terminus that has shifted down glacier 1000-1500 meters from 2001 to 2007 as seen in images from those dates below. The green line indicates the moraine position in 2007. This indicates significant flow at this point. Thus, it is evident that retreat will continue on Melbern Glacier, but should slow as either the lake basin is left behind, or the moraine band is approached

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