Glacier des Bossons, a glaciated landscape
The Glacier des Bossons or Bossons Glacier is located in the Chamonix valley in southeastern
France. The approximately 7.5 kilometre long glacier has a surface area of nearly 10 square
kilometres and is fed from the snows of Mont Blanc, the highest peak (4,807m) in the Alps. The
Glacier des Bossons has the greatest altitudinal range of all glaciers in the Alps. In 1900, the snout
of the glacier was in the Chamonix valley at 1,050m altitude; by 1980, the terminus was at an
altitude of approximately 1,200m and in 2008, was just below 1,400 metres. It is one of the few
glaciers in the world, which extend below the tree line.
Study the photograph of the Bossons Glacier below.
© r-z (Reza) 2010
http://www.flickr.com/photos/r-z/4871776972/
1. Draw an annotated sketch of the photograph. Use the following labels to annotate your
sketch:
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




glacier
snow field
pyramidal peak
arête
corrie (cirque or cwm)
exposed rock
wooded slopes
2. List the weathering processes which are occurring in the area shown in the photograph of
the Bossons Glacier.
3. What erosion processes are occurring today in Alpine areas similar to that shown in the
photograph?
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Glacier des Bossons, a glaciated landscape
4. Use the diagram below to explain the formation of a corrie.
http://en.wikipedia.org/wiki/File:Glacial_Tarn_Formation_EN.svg
© DooFi 2008
5. Explain how arêtes are formed.
6. Explain how the formation of pyramidal peaks is related to that of corrie development and
arêtes.
7. Explain why some corries contain tarns (lakes) while others do not. Illustrate your answer
with an annotated diagram.
8. As the Bossons Glacier retreats, bare rock is exposed. Explain the concept of vegetation
succession on this lithosere.
The snout of the
Bossons Glacier
© Richard Allaway
2012
http://www.flickr.c
om/photos/geogra
phyalltheway_pho
tos/7287832226/
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Glacier des Bossons, a glaciated landscape
Teaching notes
This activity can be used for work on weathering and erosion processes in a glaciated landscape.
The resource checks both understanding and application.
The activity is suitable as either a class activity individually or in small groups or as a homework
task. It could also be used as an assessment exercise.
Students could be encouraged to be aware of the value of, and the need for:



examination of photos as a source of information
field sketches
detailed annotation
It may be necessary to give some guidance on field sketch drawing. The Royal Geographical
Society provides guidelines at
http://www.rgs.org/OurWork/Schools/Fieldwork+and+local+learning/Fieldwork+techniques/Sketc
hing+and+photography.htm
Some suggested answers
Q1
A larger copy of the photograph is available in the accompanying PowerPoint. This
could be used to sketch an outline of the main features on an IWB.
Q2
Student should include reference to the following processes of weathering: freezethaw weathering, However, the photograph also shows a vegetated valley, Other
weathering processes will be active there.
Q3
This activity build on the answer to the previous question. Students need to
demonstrate that they are not only aware of freeze-thaw weathering and glacial erosion
but also addition to contemporary weathering and erosion e.g. fluvial erosion in the melt
water stream. The BBC GCSE Geography Bitesize pages at
http://www.bbc.co.uk/schools/gcsebitesize/geography/glacial_landscapes/glaciation_rev1.sht
ml also provides an overview of both weathering and erosion in a glacial landscape.
Q4-7 See http://www.youtube.com/watch?v=EF4AHb4Lt_A and/or
http://en.wikipedia.org/wiki/Ar%C3%AAte and/or
http://onlinegeography.wikispaces.com/Glacial+Landforms
Q8
This activity could be used to assess understanding of post-glacial landscapes.
The webpage http://en.wikipedia.org/wiki/Lithosere gives a clear definition of lithosere.
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Glacier des Bossons, a glaciated landscape
Additional background information on the Bossons Glacier
The Bossons Glacier in Chamonix, France, has now retreated 1,200m from its maximum extent
observed in the early 20th century. The rate of retreat is not constant; between 1980 and 1995,
the Bossons Glacier retreated 519 meters. The French website, http://www.glaciersclimat.fr/Bossons/Glacier_des_Bossons.html has a series of images comparing ‘then and now’ for
the Bossons glacier and other pages on the site cover seven other glaciers in the Mt Blanc area.
The website http://www.victorianweb.org/painting/ruskin/wc/23.html shows the Bossons glacier in
the circa 1849 painting, ‘The Glacier des Bossons, Chamouni’, by the artist John Ruskin (1819-1900).
The snout of the glacier in the mid nineteenth century was then at the level of the Chamonix
valley.
A 2012 article in the journal, ‘Climatic Change’
http://www.geo.uzh.ch/~snus/publications/nussbaumer_zumbuehl_2012.pdf provides a detailed
reconstruction of the length changes for Bossons Glacier from 1580 using more than 250
drawings, paintings, prints, photographs, maps in addition to contemporary written accounts.
The one and half-minute YouTube video at http://www.youtube.com/watch?v=DgfegU0A_l8
shows the collapse of an area of the snout of the Glacier des Bossons in July 2011.
The Bossons Glacier, viewed across the Chamonix valley
© 2009 Guillaume Baviere
http://www.flickr.com/photos/84554176@N00/3987413225
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