Rapid mass movements triggered by an atmospheric river in Disko Island, West Greenland

Mass movements can be triggered abruptly by precipitation and snowmelt and represent potential geohazards. In the polar regions, they are an important contributor to geomorphic change. This study examines a series of slushflows that occurred on Disko Island, Central West Greenland, in July 2023. These rapid mass movements are linked to an atmospheric river event that caused extreme precipitation, markedly increasing snowmelt and runoff. Pre- and post-event remote sensing imagery were used to map the affected areas, while environmental monitoring data and climate reanalysis products provided insights into the atmospheric river event. Almost 200 slushflows were mapped in Disko Island alone. During the 18-hour event, cumulative precipitation reached 115 mm, with more than 80 mm in several parts of the island, coinciding with the areas most affected by debris and snowpack mobilization. Increasing air moisture transport caused by atmospheric rivers has already been recognized as a contributor to a warmer and wetter Arctic. This work shows how extreme rain-on-snow events can trigger rapid mass movements with strong potential impact on landscape and infrastructure, suggesting the need for increased monitoring in remote areas such as Greenland.