Wednesday, December 4, 2013

Alpine Lakes Glaciers: Daniels, Foss, Ice Worm, Lynch and Hinman

First a note on the glacier posts. I am going through an exercise to be better familiar with what is going on with Washington State's glaciers. A bit over due as during a couple of my different former geologic eras I spent a lot of time tromping on glaciers. I was after bedrock exposures and my awareness of glacial history at the time was very minimal. I did have a sense of glacial retreat and suspected that a couple of my geologic interpretations were greatly enhanced by bedrock exposures due to glacial retreat.

Four of the Washington State glaciers in the Glacier Mass Balance Bulletin (GMBB) are located in the Alpine Lakes area along the high divide between King County and Kittitas County north of Snoqualmie Pass (Map Here).

Daniels, Foss, Ice Worm and Lynch are included in the GMBB.
Labels on image are from the North Cascades Glacier Climate Project.kmz
The project is a run by Mauri Pelto at Nichols College 

The GMBB has a plot of the mass balance of these 4 glaciers along with the columbia glacier at monte cristo peak and the South Cascade Glacier.

They all have lost mass since measurements began with occasional brief pauses in loss.

Pelto has brief summaries of the Daniels, Foss, Ice Worm and Lynch as well as the nearby Hinman on kzm files associated with Google Earth. They are a few years old so do not included the latest data. The GMBB indicates that each of these glaciers lost mass in 2010 but each gained mass in 2011.

Lifting directly from the kmz files off the Google Earth image:

Daniels Glacier

Daniels Glacier on the northeast side of Mount Daniels retreated only 20 m from 1950-1979. From 1979-1992 the glacier retreated another 25 m. From 1990 (right) to 2005 (left) the glacier has retreated 441 m. The upper section of the glacier has thinned and new rock areas are showing through. The long lower margin of the glacier extending to the right has melted out in 2005. The glacier is losing area rapidly and is honeycombed with subglacial caves with thin ice above, ready for more rapid retreat of this type 2 glacier.

Foss Glacier
Foss Glacier located on the northeast side of Mount Hinman, retreated 86 m from 1950-1979, 112 m from 1979-1997 and -290 m from 1997-2005. The glacier has lost half of its area since 1992. The red line shows the 1985 glacier margin on this 2005 image. Foss is a Type 3 glacier and is rapidly disappearing and with present climate will not endure.


Ice Worm Glacier
The Ice Worm Glacier has lost 40% of its area since 1984. The glacier is retreating from the top as much as the bottom. In the last four years it has lost its entire snowpack. The glacier has thinned by 15 m, which given a starting thickness of 30-40 m is nearly half of its volume gone in twenty years. The glacier is also noted and named for its extraordinary population of Ice Worms.

Lynch Glacier

Lynch Glacier on the north side of Mount Daniels retreated 390 m from 1950-1979, (1978 bottom image) almost all of it occurring in a rapid breakup of the glacier in Pea Soup Lake. From 1979-2005 the glacier has retreated 123 m from the lake shore (top image). More importantly in 2005 the west (right) glacier section, became separated from the main section by a bedrock ridge. Indicating the thinning of the glacier, this is a Type 2 glacier, and it appears only the very upper right section can survive current climate.

Hinman Glacier
In 1958 Hinman Glacier on Mount Hinman was the largest glacier between Mount Rainier and Glacier Peak, with an area of 1.3km2. By 1994, the glacier had separated into three masses with a total area of 0.2km2, and these showed no evidence of movements and will quickly disappear.


1 comment:

Adil Toorawa said...

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