The pulse of a glacier
At the fastest glacier of Kalaallit Nunaat (Greenland), Sermeq Kujalleq, high-rate field observations revealed that the sudden drainage of surface lakes generated a subglacial flood and a speedup pulse that travelled 16 km down the glacier in just 4 hours. Upon arrival at the terminus, it triggered a long calving event, providing the first evidence for a link between lake drainage and calving activity. Understanding the rapid and far-reaching impacts of meltwater on glacier dynamics is crucial in the context of accelerating Arctic warming.
Literature
Wehrlé, A., Lüthi, M.P., Kneib-Walter, A., Nap, A., Rousseau, H., Jouvet, G., Walter, F.Velocity and calving response of a major Greenland ice stream to a lake drainage event. Nat. Geosci. 19, 84–89 (2026). https://doi.org/10.1038/s41561-025-01858-2
Image: Adrien Wehrlé