Greenland’s Cracks That Stay Put: What Crevasses Reveal About Meltwater and Ice Flow

Takeaway: In Pâkitsoq, Greenland, the cracks mostly stayed put for ten years, but their changing size may shift where summer meltwater reaches the ice sheet’s hidden floor.Greenland’s ice sheet is not just melting at the edges; every summer, water also runs across its surface, finds openings, and may plunge toward the bed far below. That hidden plumbing matters because water at the base can change how fast ice slides toward the ocean. In this episode, we visit Pâkitsoq in central-western Greenland, where researchers used satellite radar and a new deep-learning tool called MimiNet to map crevasse fields year by year from 2015 to 2024. The surprising result: many crevasse fields stayed in the same places for a decade, while their total area grew and shrank from year to year with no clear long-term trend. We talk through what radar “sees,” why crevasses are different from moulins, how AI can help map ice-sheet hazards, and what the uncertainty means for understanding future sea-level rise.Citation: Khan N, Poinar K, Briner J, Nowicki S, Mejia JZ, Avellaneda A and Verné M (2026) Steady crevasse locations in Pâkitsoq, Greenland, over one decade: Results from MimiNet, a new deep-learning model for crevasse detection. Journal of Glaciology 72, e69, 1–19. https://doi.org/10.1017/jog.2026.10185Disclosure: This Waterlines episode package is written for production using AI-generated voices.