Fig. 3: Statistics about rockfall distribution in space and time.

Statistics highlight the spatial distribution of rockfalls and its implications. More rockfalls occur in highland terranes and the majority of rockfalls occur in Imbrian terranes, while Nectarian (N) and even pre-Nectarian sites (pre-N) feature a substantial number of recent rockfalls (~25%). Owing to inaccuracies in the underlying geologic map, the number of rockfalls in ancient terranes is potentially reduced in favor of the Copernican and Eratosthenian bins (see Supplementary Fig. 5). The normalization of the CNN-derived rockfall counts over area in the regions provides a first-order estimate (power law fit, black dashed line) of the advective erosion rate of the lunar topography and its evolution over time (Eq. (1) in the “Methods” section). Geologic lunar timescale based on refs. ^56,57.