FIELD INVESTIGATIONS OF PERMAFROST AND CLIMATIC CHANGE IN NORTHWEST NORTH AMERICA

摘要: Yukon Territory, adjacent portions of Northwest Territories, and Alaska contain a continental range permafrost conditions. The response to climatic change is recorded in the cryostratigraphy late Pleistocene Holocene sediments, with an early thaw unconformity being widespread prominent feature. More recently, temperature profiles from deep boreholes show inflection associated near-surface warming 2i 4iC since Little Ice Age. Simultaneously, southern limit has moved northwards. In order understand present climate:ground system, analytical solution been verified relate annual mean ground surface under equilibrium Ground temperatures have obtained air using n-factors. assumes that heat transfer active layer only by conduction. relations impact on changes snow cover soil moisture conditions may surpass effect per se. Observations sporadic zone indicate persistence despite recent warming. This due minimal residual peat landforms, latent ice-rich ground. further complicates interpretation climate change.