Greenland’s Hidden Water: How Snow Aquifers May Open New Drains Through Ice

Takeaway: On Helheim Glacier, hidden meltwater in the snow can turn small cracks into deep drains that let water reach the bed farther inland. Greenland’s ice sheet is not just melting at the edges. In some snowy high places, meltwater is stored inside the ice sheet like a buried, slushy reservoir—and where that hidden water finds cracks, it may change how glaciers move. This episode follows new work from Helheim Glacier in southeast Greenland, where researchers combine radar, satellite images, GPS stations, and fracture modeling to ask whether these underground firn aquifers can begin draining farther inland as the climate warms. We unpack what a firn aquifer is, why crevasses can become vertical pipes to the glacier bed, and why tiny changes in crack depth or water level may matter for ice flow, sea level, and the way scientists model Greenland’s future. The study is preliminary and careful: it identifies vulnerable places and early signs of change, not a finished forecast. Citation: Mejia JZ, Poinar K, Meyer CR, Sommers AN, Chu W (2025). Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland. Journal of Glaciology 71, e5, 1–11. https://doi.org/10.1017/jog.2024.78. This episode uses AI-generated voices.