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TitleGround ice degradation and thermokarst terrain formation in Canada over the past 16 000 years
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorWolfe, S AORCID logo; O'Neill, H BORCID logo; Duchesne, CORCID logo; Froese, D; Young, J M; Kokelj, S V
SourceGeological Survey of Canada, Scientific Presentation 134, 2022, 1 sheet, Open Access logo Open Access
PublisherNatural Resources Canada
MeetingArctic Change 2021; December 2021
Mediadigital; on-line
RelatedThis publication is related to the following publications
File formatpdf
ProvinceCanada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long WENS-141.0000 -50.0000 90.0000 41.7500
Subjectssurficial geology/geomorphology; environmental geology; Nature and Environment; Science and Technology; permafrost; ground ice; periglacial features; thermokarst; ice wedges; models; landslides; slumps; subsidence; creep; hummocks; landforms; terrain types; Climate change; permafrost thaw; lithalsas; palsas; Databases; Phanerozoic; Cenozoic; Quaternary
Illustrationsgeoscientific sketch maps; tables; photographs; satellite images
ProgramGEM2: Geo-mapping for Energy and Minerals TransGEM
Released2022 03 15
Thermokarst results from thawing of excess ground ice in permafrost sediments. Thermokarst processes and landforms are controlled by ground ice type, amount and distribution, as well as the patterns of ground ice loss over time. Recent acceleration of varied thermokarst processes across diverse Canadian permafrost terrains make for a challenging task in predicting landscape-scale thaw trajectories. Using existing ground ice models, we examined the modelled amounts and spatial extent of ground ice loss relative to ground ice maxima in the last ca. 16 ka BP for relict, segregated and wedge ice. We relate observed thermokarst features to the nature of ground ice development and loss in different environments (cold continuous permafrost, discontinuous permafrost, and no current permafrost). In cold, continuous permafrost areas where ground ice loss has been limited over the last 16 ka BP, thermokarst processes include active layer detachments and slumps in segregated and relict ice, gullying and ponding in ice wedge troughs, and the cyclical development of shallow thermokarst ponds in segregated ice. With ground ice loss in discontinuous permafrost, thermokarst processes are wide-ranging. Slumps, subsidence, and collapse of lithalsas, palsas and peat plateaus occur from thawing of segregated ice, thermokarst ponds from melting wedge and segregated ice, and involuted terrain from melting and creep of relict or segregated ice. In former permafrost terrain, evidence of thermokarst includes former ice wedge polygons, collapsed lithalsas, and irregular hummocky terrain. The relations between modelled ground ice loss and observed thermokarst landscapes assist in understanding present-day processes and in predicting future thermokarst landform evolution with a changing climate.
Summary(Plain Language Summary, not published)
We examine the relationship between the modelled ground ice loss in permafrost terrain to thermokarst processes and landforms in Canada.

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