The Greenland ice sheet could serve as a significant source of the micronutrient iron to the North Atlantic Ocean, reports a study published online in Nature Geoscience this week. The magnitude of this source is likely to increase as the melting of the ice sheet escalates in a warming world.

Maya Bhatia and colleagues measured the concentration of iron in meltwater draining the western margin of the Greenland ice sheet. They report significant quantities of biologically available iron in the meltwaters. Scaling up their findings to the entire Greenland ice sheet, they suggest that it could deliver as much iron to the North Atlantic as atmospheric dust, previously thought to be the main source of iron to the region.

In an accompanying News and Views article, Rob Raiswell says they “show that meltwaters of the Greenland ice sheet pick up significant quantities of bioavailable iron beneath the ice en route to the ocean.”