Assessment of permafrost subsidence hazards in Arctic settlements using InSAR methods

Abstract

Rapid warming in the Arctic region intensified permafrost degradation, increasing the exposure of communities and infrastructure to permafrost-thaw related hazards. Detecting and monitoring subsidence is essential to support risk mitigation and adaptation planning. In this study, Persistent Scatterer (PS) and Distributed Scatterer (DS), Interferometric Synthetic Aperture Radar (InSAR) techniques were applied to assess vertical ground displacement across seven Arctic permafrost settlements representing diverse environmental and land-use settings. Inter-annual displacements and time series from 2016 to 2024 were analysed and validated against in-situ measurements and observations. This study provides a multi-site inter-comparison of PS-InSAR and DS-InSAR performance across several settlements not previously investigated using InSAR. Results show spatially heterogeneous subsidence patterns, with infrastructure areas in ice-rich tundra environments significantly more affected than those in high-Arctic settlements, with highest rates of 62 mm yr (Formula presented.) measured for buildings in Bovanenkovo. The comparative analysis indicates consistency in displacement trends (55–67% agreement), but also identifies method-dependent biases. Spatial filtering likely explains negative proportional biases but can improve the estimation displacement magnitude relative to PS-InSAR. Constant offsets are attributed to reference location discrepancy. Both methods underestimate long-term displacement relative to validation data; however, PS-InSAR shows higher accuracy and allows to measure abrupt subsidence relevant to infrastructure stability. Both methods agree well with in-situ observations of infrastructure damage, confirming their potential for risk assessment. In addition, this study shows new evidence of PS-InSAR application beyond infrastructure for lowland permafrost landforms monitoring. These results highlight the complementarity of the two techniques for interpreting subsidence hazard. The resulting displacement maps and time series provide useful information to support Arctic communities in hazard assessment, spatial planning, and adaptation strategies.