Fig. 2
Distribution of fallout deposits resulting from the 8 October 2016 Mt Aso eruption within approximately 330 km (a) and 30 km from the vent (b). The accumulation per unit area (black characters, g/m2) and maximum observed grain size (white characters, mm) are indicated for each sampling site (black dots). The maximum grain size of the ash fallen at the MTY site is based on our measurements from Fig. 4l of Sugawara (2017). The interpreted isomass (red to pale green-shaded areas, g/m2) and maximum clast contours (white dashed lines, mm) were hand drawn to fit the observed data. The black dashed line in the top figure indicates the zero accumulation line of Fukuoka Regional VOWC (2016), which was used in the total grain-size calculation. Circles represent radii of 50, 100, 200, and 300 km from Nakadake crater. The black dashed line in b indicates the Aso caldera wall