Geospatial analysis of permafrost thaw-induced slope processes and their hazard potential across the Arctic

Abstract

In recent decades, the Arctic has warmed at a rate that significantly exceeds the global mean, a phenomenon commonly referred to as Arctic amplification. Studies consistently show that Arctic temperatures are increasing at a rate roughly two to four times the global average, highlighting the exceptional sensitivity of northern environments to ongoing climatic change. Permafrost thaw is increasingly destabilizing high-latitude and high- altitude landscapes, giving rise to a range of slope failures with growing implications for ecosystems, infrastructure, and human activity. This dissertation examines thaw-driven mass-wasting processes across multiple spatial scales, focusing on retrogressive thaw slumps (RTSs) and active-layer detachment failures (ALDs) as dominant expressions of permafrost degradation under a warming climate. Integrating circumpolar susceptibility modeling, regional comparative analysis, applied infrastructure exposure assessment, and a tourism focused case study, the thesis develops a multiscale framework for understanding where thaw-related slope instability is likely to occur, how controlling factors vary among permafrost landscapes, and why these processes matter for society.

At the circumpolar scale, statistical susceptibility modeling identifies consistent hemispheric patterns in RTS occurrence associated with climatic conditions and terrain settings commonly linked to ice-rich permafrost. Comparative regional analyses demonstrate that RTSs occupy distinct environmental envelopes throughout cold regions, highlighting pronounced environmental heterogeneity between regions. Regional-scale modeling of ALDs across Alaska and northwestern Canada reveals strong associations with slope morphology, cold-climate conditions, and fine-grained soils and shows extensive overlap between susceptible terrain and critical infrastructure networks. A local-scale synthesis in Yukon protected areas further illustrates that thaw-driven geomorphic hazards intersect with tourism, heritage, and governance, extending permafrost risk beyond infrastructure and settlements to transient human presence.

Collectively, the results show that thaw-related slope failures are governed by consistent classes of environmental controls, such as climate and topography, whose expression and consequences are fundamentally scale-dependent. By linking physical susceptibility with environmental heterogeneity and patterns of human use, this dissertation advances an integrated perspective on permafrost thaw as a coupled socioenvironmental phenomenon. The findings provide a scientific basis for anticipated impacts of accelerating permafrost degradation and support the development of multiscale adaptation strategies in rapidly changing cryospheric environments.