Fig. 2: Erosion signals for non-glaciated and glaciated regions and the relative effect of human activities on erosion rates in Lake Bourget catchment.

Sediment yields (expressing erosion rates) for both the (a) non-glaciated (in orange) and (b) glaciated regions (in blue) of the Lake Bourget catchment, and (c) the effect factor of human activities on erosion in the non-glaciated region (blue to red shading), computed as a ratio between the measured erosion rate and the expected erosion rate in the absence of human impact (Supplementary Method 6; Supplementary Fig. 7). These two erosion signals were computed from the detrital silicate flux, the mixing model, the ɛNd data obtained on both the sedimentary sequence and the river sediments, and by calculating the areas of the glaciated and non-glaciated region in the catchment (Method). The error bars correspond to the standard deviation obtained using a Monte Carlo approach (Method). Colour shading of erosion signals in glaciated and non-glaciated regions highlights increases in intensity compared with early Holocene values. On panel (a), the erosion signal for the glaciated region has been normalised to the correlation period values to highlight periods where erosion rates are dissimilar between the two regions. On panel (c), the magnification scale represents the effect of human activities on erosion compared with the theoretical value calculated for erosion impacted solely by climatic fluctuations. Periods: Pre-anthropic (until 5250 yr BP), Neolithic (5250–4200 yr BP), Early Bronze-Age (4200–3600 yr BP), Mid to Late Bronze-Age (3600–2600 yr BP), Iron Age (2600–1980 yr BP), Roman Period (1980–1750 yr BP), Post (P) Roman Period (1750–1474 yr BP), Early (E) Middle Age (1474–950 yr BP), High (H) Middle Age (950–650 yr BP), Late (L) Middle Age (650–458 yr BP), Early (E) Modern (458–161 yr BP), Late (L) Modern (161–4 yr BP), Co: Contemporary (4 yr BP – present). Source data are provided as a Source Data file.