Arctic is warming two to four times faster than any other place on the planet. It can significantly affect permafrost, which is crucial to the region’s ground stability. This study focuses on a river and lake-rich area located near Ikaluktutiak (Cambridge Bay, Nunavut). Although little is known of permafrost conditions, local observations indicate that episodes of abrupt and localized permafrost degradation have increased in the past decades. Therefore, it represents a key site for studying and monitoring the effects of permafrost thaw on local aquatic ecosystems and northern communities. This project aims to detect past and recent indicators of degrading permafrost and assess its impacts on aquatic ecosystems through remote sensing, geomorphology, and limnology. More specifically, this project will focus on assessing the hydrological stability of lakes, analyzing variations in lake surfaces over time, and mapping the geomorphological origins and hydrological connectivity of these lakes. The stable isotope composition of different water sources, including active-layer groundwater and ground-ice was analysed to assess their contributions to sampled lakes and ponds. Our preliminary results revealed diverse lake morphologies, ranging from shallow, flat lakes to deeper lakes with variable bathymetric topography. Permafrost cores (1.5 m) indicate high ground ice content with low amounts of organic matter. Turbidity measurements in a tributary of Kitigaq River, where subsistence fishing occurs, indicate above-normal turbidity values after the degradation of ice-rich permafrost. These findings highlight the importance of monitoring permafrost degradation in this understudied area since it has implications for both ecosystem health and local community.
Author: Loek Pascaud