Fig. 5From: Estimating the ashfall volume for a small eruption using ellipse-approximated isopach analysis: how many seeking points are required to determine a suitable axis?Probability density function of the EAI volume with 1–4 seeking points. a Result of the one-point seeking cases. b Result of the two-point seeking cases. c Results of the three-point seeking cases. d Results of the four-point seeking cases. The table at the bottom denotes the EAI analysis results with different point-seeking numbers for the small eruption of Shinmoedake volcano on June 27, 2018Back to article page