Fig. 4

a ALOS-2 image of central to eastern part of Nishinoshima (11:18 JST on 6 December 2019). b Simulation results with assumed effusion rate of 0.47 × 106 m3 day−1 (equivalent to lava-effusion rate at Nishinoshima on 6 December 2019 minus portion consumed by pyroclastic cone building). c Simulation results with assumed effusion rate of 0.20 × 106 m3 day−1 (corresponding to average value for 2013–2015 Nishinoshima activity)