NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, active layer, permafrost, soil, permafrost degradation, ground ice, hydrological processes, erosion

Objective(s): In permafrost terrain, an ice-rich zone is frequently found just below the base of the active layer (Mackay, 1972; Burn, 1988). The ice-rich zone is significant because it is widespread in permafrost areas and may act as a significant hydrological reservoir (Hughes, 1974). It is close to the base of the active layer, therefore human disturbance or climate warming which may lead to thawing could result in local subsidence and terrain instability. The proposed research will investigate the physical and chemical characteristics of the near-surface ice-rich zone in sediments of the Mackenzie Delta area. The goals of the research are to investigate the relationship between ice-rich permafrost and forest structure. While the tilting of trees in forests underlain by permafrost is of ecological interest, determination of the processes that caused the trees to lean is of practical utility. Near-surface ground ice is of geotechnical significance because disturbances leading to its thawing can result in surface subsistence and terrain instability. Identification of potentially sensitive terrain in Mackenzie Delta is currently required to plan the development and manage the impacts of renewed hydrocarbon exploration and future gas production in the region. Data collection in 2002, in the Inuvik area will include determining the ice content of near-surface permafrost and evaluating the tilt characteristics of overlying trees to verify this relation.