Correction to: Scientific Reports https://doi.org/10.1038/s41598-017-10220-5, published online 29 August 2017

In Figure 2c, the columns for CR3 and CR4 have been obscured. The correct Figure 2 appears below as Figure 1.

Figure 1
figure 1

Average data about natural radioactivity (panel a), elemental composition (panel b) and carbonaceous content (panel c). In the first two panels average results about cryoconite and moraine sediments are presented (dark and light colors respectively). Not all nuclide labels are reported for U and Th chains, see Fig. 3 for the complete list. In panel c data related to single sample are shown, lines refer to average and standard deviation values. Asterisks highlight to values below detection limit.