Spatial and temporal patterns of fracture in confined landfast sea ice

Abstract. Fractures in sea ice form when internal ice stresses exceed ice strength. The locations of recurring fractures in landfast sea ice are well known to Arctic Indigenous communities, but recent observations suggest changes in their timing and frequency driven by changes in the Arctic climate. Fractures affect sea ice stability, travel safety, and ocean-atmosphere exchanges, so understanding why, when, and where they occur is increasingly important with climate change. To improve predictions of fracturing and support safe travel, we analyze fracture patterns in Admiralty Inlet, Nunavut, Canada, a semi-enclosed waterway. Using satellite imagery from 2018 to 2023 and guided by Inuit Knowledge of recurring fracture zones, we examine how geographic, atmospheric, and oceanographic factors shape fracture behaviour. This study provides the first assessment of fracturing in a semi-enclosed landfast ice environment in the Canadian Arctic Archipelago, extending previous work focused on open-coast environments. We find that seasonal changes in ice properties such as ice thickness, temperature, and porosity largely control fracture timing. Our results further indicate that episodic high-stress events such as wind storms are not primary drivers; instead, stable geographic features such as points of land concentrate stress and govern fracture locations. These findings highlight the need for in-situ measurements of ice strength, under-ice currents, and sea surface height, as well as higher temporal resolution fracture monitoring. By integrating remote sensing, environmental datasets, and Inuit knowledge, this work advances understanding of landfast ice stability and improves predictive capabilities relevant to both community travel safety and Arctic climate modelling.