Fig. 3
From: Open source data mining infrastructure for exploring and analysing OpenStreetMap
World map depicting changes in the OSM database. Every change of nodes in the data is depicted as a disk, and the number of changes at that particular point in place and time is encoded by the size of the disk. Changeset data Ⓒ OpenStreetMap contributors (cf. www.openstreetmap.org/copyright). a 2018-04-02, 6:00 a.m. (UTC) b 2018-04-02, 10:45 a.m. (UTC)