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Entrevue à Radio-Canada

Pascale était en entrevue à Radio-Canada le 22 octobre 2018 pour parler de sa recherche sur le pergélisol avec Caroline Borduas et Isabelle Fleury.

Pascale avec Caroline Borduas au studio de radio-Canada à Sudbury

Voici les liens vers l’entrevue (en deux temps) partie 1 et partie 2.   Bonne écoute!

 

Field work in the Blackstone Uplands, Yukon

Fieldwork in the Blackstone Uplands (August 2nd to 22nd, 2018) was uneventful this year, although the weather was rather cold and rainy. Below are some photos of Maude (who joined the trip to lend a hand), Pascale, and baby-Florent in the field.

 

Pascale visiting the basin of a drained seasonal pond

Maude setting up temperature sensors in a thermokarst initiation feature

Pascale and Florent downloading data loggers

Pascale presented at the 2018 Yellowknife Geoscience Forum

 

Pascale (and baby Florent!) participated in the 2018 Yellowknife Geoscience Forum, which had a very good turn out of permafrost scientists!

Pascale presented a poster with some data and thought son the Evolution of incipient lowland thermokarst features in the Blackstone River valley, Yukon (abstract on p. 108 of the Forum’s book of abstracts).

 

 

 

 

Pascale also presented a brief overview of the thermal monitoring and geomorphological mapping work carried by Maare Packalen, Jim McLaughlin, and Zlatka Pironkova in Ontario Far North. See Permafrost monitoring in the Hudson Bay Lowlands: preliminary results from the Ontario Far North in the Forum’s book of abstracts, p. 60.

 

 

The stirring committee of the new Canadian Permafrost Association used the opportunity to have a fruitful meeting in person. The new association should be up and running this summer! Kumari Karunaratne and Toni Lewkowicz gave a presentation to update the community and gather input regarding the mission statement, logo, etc. See The formation of a Canadian permafrost association in the abstract book of the Forum, p. 44.

Permafrost degradation occurs beneath shallower water than expected in northern Yukon

Methane escapes from a hole drilled through lake bottom sediment  (photo credit: Z. Braul)

A paper published by Roy-Leveillee and Burn (2017)  in the Journal of Geophysical Research- Earth Surface  reports observations of permafrost degradation and talik development beneath water depths less than 15% of the maximum ice thickness in lakes of Old Crow Flats, northern Yukon.  This is surprising as,  in the near-shore zones of thermokarst lakes, it is generally assumed that permafrost is sustained where water depth is less than 60% of the local maximum ice thickness.

 

 

 

Jet-drilling to delineate the talik permafrost boundary  (Photo credit: P. Roy-Léveillée)

The paper investigates controls on permafrost degradation and reveals that sub-lake permafrost is sensitive to on-ice snow distribution where the water column freezes through. It shows the importance of the thermal offset where conditions are marginal for talik initiation and highlights the role of interannual variability for prompt talik initiation near receding shores.

These findings improve understanding of permafrost degradation beneath shallow water, a topic of  particular concern in the context of climatic warming as methane release from thaw lakes is concentrated near receding lake margins and is most active at the thaw front beneath the lake bottom.