Glaciers around the world have shaped landscapes by carving deep valleys, depositing fertile soils, and continuously reshaping the Earth’s surface. But how quickly do glaciers erode the land beneath them?

A new study published in Nature Geoscience offers the most comprehensive global assessment yet of glacier erosion rates and their impact on landscapes. Led by University of Victoria geographer Sophie Norris and an international team, the research estimates future erosion rates for more than 180,000 glaciers worldwide.

Using a machine learning approach, the team analyzed data covering approximately 85 percent of modern glaciers. Their model predicts that 99 percent of glaciers erode at rates between 0.02 and 2.68 millimeters per year—about the thickness of a credit card.

“Our analysis shows that the factors influencing erosion beneath glaciers are more complex than previously understood,” says Norris. “Variables such as temperature, the amount of water at the glacier base, the types of surrounding rock, and geothermal heat all strongly affect erosion rates.”

Measuring erosion beneath active glaciers is extremely challenging, especially in remote regions. John Gosse of Dalhousie University notes that this study provides valuable estimates for locations around the globe where direct measurements are nearly impossible.

Understanding the factors driving glacial erosion is important for managing landscapes, planning long-term nuclear waste storage, and tracking the movement of sediment and nutrients across ecosystems worldwide.

Norris began this research during a postdoctoral fellowship at Dalhousie University and completed it at the University of Victoria. The international collaboration included researchers from the University of Grenoble Alpes in France, Dartmouth College, Pennsylvania State University, and the University of California Irvine in the United States. The study was conducted in partnership with and supported by the Canadian Nuclear Waste Management Organization.