Thoughts on some Ellesemere Island Glaciers Geomorphology

November 6, 2014 in post by Fortier.D

Ellesmere Island, Nunavut. Several valley glaciers flowing into a former glacier valley, now filled with sea ice. Some of these glaciers form glacio-fluvial deltas. Note the decreasing altitude of delta sediments which is due to isostatic uplift. Exposed deltaic sediments are submitted to severe periglacial conditons and frost-cracking is common as evidenced by the presence of ice-wedge polygons (Photo D. Fortier © Geocryolab).

 

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Thermokarst landscape, Interior Alaska near Fairbanks.

November 4, 2014 in post by Fortier.D

Yedoma deposits (Late Pleistocene sedimentation and freezing in unglaciated areas) are extremely ice-rich. Over time thermokarst modifies the landscape to trigger the developments of various landforms, here along and in an alluvial plain with meandering river. In this picture, we can observe several thermokarst lakes, some of which were drained, thaw ponds, peatlands, peat edge along lake margins, and collapsed bogs (Photo D. Fortier © Geocryolab). Fluvial activity plays a role in the life-cycle of these aquatic thermokarst ecosystems, draining ponds and lakes as rivers meander. Thermokarst landscape can play an important role in the climate system by releasing carbon sequestrated in the permafrost back to the atmosphere via oxidation and microbial activity.

 

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by Kate G.

Frédéric Bouchard at “Les années lumière” (Radio-Canada)

November 3, 2014 in post by Kate G.

Frédéric Bouchard, post-doctoral fellow at the Geocryolab, talks about glaciations in a series of 3 audio clips on the show «Les années lumière» at Radio-Canada!

Next clip: Next Sunday between 12h10 – 14h

It is also possible to replay the clips by visiting Radio-Canada’s website:
http://ici.radio-canada.ca/emissions/les_annees_lumiere/2014-2015/