Dispersal and grain size characteristics of the May 14, 2018 Shinmoedake eruption deposit, Kirishima Volcano, Japan, based on post-eruption field survey and meteorological datasets

Earth, Planets and Space

Table 1 Mass of tephra discharged and isomass area for each survey case for the May 14, 2018 eruption deposit analyzed in this study

Case	Case 1		Case 2
Used data	Distal (> 7 km) data		Proximal (3–4 km) and distal (> 7 km) data
Used data	Mass (g/m²)	Area (km²)	Mass (g/m²)	Area (km²)
Mass in vent area	592	0.0003	2683	0.0003
Drawn isomass and area			2000	1.0301
			1000	2.5383
	500	2.5288	500	4.7316
	400	5.2835	400	7.0755
	300	10.8938	300	12.3822
	200	19.5572	200	20.8152
	100	38.6822	100	39.4625
	50	72.7971	50	73.9510
	20	141.3119	20	143.1269
	0	296.4031	0	297.1475
Calculated mass (kg)		1.6 × 10⁷		2.1 × 10⁷

The mass in the source vent area was estimated by extrapolating the straight line that connects the maximum isomass with the second maximum isomass to the area of the source vent (approximately 20 m in diameter)