Portion of Greenland magnetism comes from extraterrestrial source

Part of the magnetic dust observed in Greenland ice cores may come from extraterrestrial sources, although most of the surface magnetism of ice also comes from iron-rich particles deposited by airborne dust. Lanci et al. used magnetic testing techniques on ice cores from central Greenland to trace the iron oxide content and total dust concentration in polar sources.

They suggest that measuring the magnetic strength of dust deposited on the icy surface can provide researchers an improved method to estimate the source of airborne aerosols and reconstruct ancient climate changes. Such magnetic testing methods had previously been applied to environmental analyses of windblown particles deposited on land but had never been used within ice.

The authors examined the faint magnetic signal from mineral particles trapped under layers of frozen sediment in Greenland and, although they cannot rule out alternative sources of iron dust contamination, found that the observed magnetization is closely correlated with the dust concentration in the ice.

Title: Magnetization of Greenland ice and its relationship with dust content