A history of water and ice: a field guide to permafrost and environmental change in the Yellowknife area, Northwest Territories

Abstract

Permafrost is a fundamental component of northern landscapes and is inextricably linked to climate. The changing state of permafrost due to global warming has heightened its environmental and societal relevance. Permafrost refers to soils and rock that remains below 0°C, or commonly considered mp;lt;"frozenmp;gt;", year-over-year, and it affects most of the terrain in the northern half of Canada. For thousands of years, permafrost has affected the landscape around Yellowknife. The occurrence and characteristics of permafrost in this region intimately relate to the history of glacial ice sheets and glacial lakes, which have had a dominant influence on the evolution of this landscape. Knowledge of the connections between permafrost conditions, climate, and geological history highlights why northern landscapes are now amongst the most dynamic on earth. The purpose of this guidebook is to describe the influence of permafrost on landscape of the Yellowknife region, and to illustrate how our geological legacy has shaped the land that we live on today. It is increasingly evident that permafrost, which provides a foundation for northern ecosystems and communities, is not permanent. In many areas, permafrost is thawing in response to natural environmental disturbances, due to human activity through the development of infrastructure, and by climate warming. Understanding how these changes impact the environment and infrastructure are critical to the resilience of northern society. This guidebook provides an overview of the environmental and permafrost conditions in the Yellowknife area. Part I describes the characteristics of permafrost and its influence on the environment and on northerners. Part II describes the landscape around Yellowknife, highlighting the legacy of Glacial Lake McConnell and its imprint on the present day geography and permafrost conditions of the Great Slave Lowland region. Part III presents a tour of Yellowknife and the surrounding region, describing field stops that illustrate landscape history, local permafrost conditions, and the consequences of permafrost thaw.