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Adam and Pascale present at EUCOP 2018 in Chamonix

EUCOP 2018 took place in beautiful Chamonix, and was a success with more than 400 conference attendees from 29 different countries. (During the conference, these attendees consumed 2000 pastries per day, 60 L of red wine, 30 L or white wine, and 2000 beers. Can you tell we were in France?)

Pascale gave the opening talk for the thermokarst lake session on Thursday the 28th. She presented a discussion of the influence of vegetation structure on the geomorphic evolution of thermokarst lakes in the forest tundra transition.

Adam presents to a full room a EUCOP, it was difficult to get a photo!

Adam attended the PYRN (Permafrost Young Researchers Network) workshops along with approximately 170 young researchers from June 22nd to 24th. He presented his undergraduate thesis research on greenhouse gas production production potential from degrading palsa fields of the Hudson Bay Lowlands  in the session on permafrost peatlands, on Tuesday the 26th. The room was overflowing, with people sitting on the floor and filling the hallway in front of the door.

Adam wins a Weston WCS-Canada fellowship in northern conservation

Sam Hunter and Adam Kirkwood extract a permafrost cores from a palsa in Polar Bear Park

Sam Hunter and Adam Kirkwood extract a permafrost cores from a palsa in Polar Bear Park, Ontario.

Adam Kirkwood won a Weston Wildlife Conservation Society-Canada Fellowship for his M.Sc. project on The significance and vulnerability of carbon and mercury stores frozen in palsa mires of the Ontario Far North. He will be working on cores extracted from intact, partially degraded, and degraded palsas extending along a latitudinal gradient between Peawanuck and Attawapiskat. Adam will 1) characterize the microbial community in the cores with eDNA (targeting methanogens, SRB and Hg methylation genes with sequencing and qPCR); 2) incubate the samples to assess greenhouse gas production potential; and 3) analyzed them for total mercury and methyl mercury content.

This project is a collaboration with researchers from the Ontario Ministry of Natural Resources and Forestry, who have equipped the palsa gradient with climate stations, permafrost monitoring stations, and flux towers, and with the BIOTRON Institute for Experimental Climate Change Research at Western University, and the Vale Living with Lakes Center at Laurentian University.

Field work on a palsa

Adam Kirkwood, Mark Crofts, and Benoit Hamel take field notes and package a permafrost core before leaving a site.

Adam’s project directly addresses concerns and priorities identified by the Muskegowuk Council, which has given its support to the project, and we look forward to sharing information with Muskegowuk communities. A poster in Cree and English (Greenhouse gas emissions from thawing permafrost in Polar Bear Provincial Park – ᑲᑎᑭᑌᐠ ᐱᑐᐡ ᑲᑎᑭᐠ ᐁ ᐃᔑ ᑭᔑᑲᐠ) with information on some aspects of this project was presented earlier this year at the Muskegowuk Climate Summit.

Emma presented her work on beaded streams at the CAG annual meeting at York U

On June 1st, 2017, Emma Ciric presented her research on beaded streams at the Canadian Association of Geographer Annual Meeting at York University. Her poster was very well done, particularly for a first poster (!), and can be viewed here. Emma has now graduated from Laurentian University and went on to pursue a MSc in Coastal and Marine Science at the University of Algarve, in Portugal.

Permafrost teaching lab: Doug’s scale model of oriented lakes

Douglas Massel is an undergraduate student from the LU Outdoor Adventure Leadership (ADVL) Program. Potentially interested in pursuing a career as a field technician for research expeditions in remote areas, Doug added a minor in Geography to his ADVL degree, and focused on physical geography courses. In the permafrost class this year, Doug is writing his term paper on the orientation of thermokarst lakes. He added a scale model experiment to his paper, to examine the hypothesis that sediment texture affects the direction of lake elongation in relation to dominant winds, as proposed in Roy-Leveillee and Burn, 2015. Doug has been busy in the lab blowing wind over trays of wet sand and silt with puddles in them to look at circulation and lake expansion patterns.

Doug’s scale model: wind is blowing (upper left), sediment is moving (bottom left), Doug is watching his lake expand.

 

In summer 2017 Doug will be working as a field assistant in the Canadian NW Arctic with Chris Burn from the Carleton Permafrost Group. Best of luck Doug, and send some photos!

 

 

 

New conceptual model for the genesis of drained thermokarst lake basin topography

 

6basins_100dpi

Examples of drained thermokarst lake basins with wet, depressed margins and drier ground near the basin centre (all pictures from Google earth): a) Fish Creek Area, Alaska; b) Tuktoyaktuk Peninsula, Northwest Territories; c) N Seward Peninsula, Alaska; d) Dewey Soper Bird Sanctuary, Baffin Island, Nunavut; e) Ayon Island, Chukotka, Siberia; f) Penzhina River area, Kamchatka Krai. Figure 2.6 from Roy-Leveillee, P. (2014) Permafrost and thermokarst lake dynamics in the Old Crow Flats, northern Yukon, Canada. Ph.D. Thesis, Carleton University: Ottawa, Canada.

A paper published by Roy-Leveillee and Burn (2016)  in Earth Surface Processes and Landforms  presents a new geomorphological model for the drained basin of thermokarst lakes in tundra areas.

Drained lake basins are widespread in Arctic lowlands affected by thermokarst and, in tundra areas, the topography of these basins typically constitutes a wet, depressed margin surrounding a slightly elevated, better drained centre. This low grade geomorphological feature is widespread in Arctic lowlands (see satellite images to the right), yet the genesis of this topography is poorly understood.

Based on conditions observed in Old Crow Flats, this new model suggests that patterns of sediment deposition along the lake bottom during lake expansion is what causes the raised centre and depressed margins revealed once permafrost is re-established in the drained basin floor (see diagram below).

This new model differs from that presented by Jorgenson and Shur based on observations of conditions in drained basins of the Alaska Coastal Plain. Their model relied on the poor frost-heave potential of gravelly sand which may accumulate near shore and the influence of shallow littoral terraces on permafrost configuration beneath lakes. This model raises the problem of equifinality, as similar topography develops in areas such as Old Crow Flats, where  lakes lack littoral shelves and develop in fine-grained glaciolacustrine silts (no sand or gravel).

This new conceptual model relies on a mechanism that is applicable in any location where lake shore bank erosion leads to the redistribution of sediment by wave action along the lake bottom. Differences in ground ice content may accentuate the elevation differences between basins and margins in some areas, as reported from the Beaufort Coastal Plain, but it did not in Old Crow Flats.

 

Ch6Fig15_model

Conceptual model of sedimentation patterns during thermokarst lake expansion (left) and resulting topography after lake drainage and permafrost aggradation (right). Sediment deposits that are in permafrost are marked with a light grey pattern. From Roy-Leveillee and Burn 2016, Fig 15.