Fig. 8
Volatile content of melt inclusions and groundmasses: a H2O - versus CO2 contents, b S - versus CO2 contents, c H2O - versus S contents, and d Cl - versus S contents. Error bars indicate analytical errors for H2O and CO2 by SIMS and S and Cl by EPMA. The analytical errors in H2O by EPMA in c are ± 1 wt % (Saito et al. 2018). H2O and CO2 contents in melts (M1 and M2 magmas at pressure ranges of 50–500 MPa and F1, F2, A1, A2, B1, and B2 magmas at pressure ranges of 50–200 MPa) calculated using the MELTS program (Additional file 9) are also shown. Sold and broken curves in (a) indicate solubilities of the H2O-CO2 gas mixture in the 2011 mafic melt (Table 4) at 1030 ºC and the 2011 felsic melt (Table 4) at 870 ºC, respectively, calculated using the solubility model of Ghiorso and Gualda (2015). Gray lines with circles in c and d indicate mixing of mafic and felsic melts in the 2011 magma (Table 4). Red lines with circles in c and d indicate mixing of mafic and felsic melts in the 2018 magma (Table 4). Blue and red curves with arrows in a show expected compositional changes in the melts resulting from a decrease in the pressure of the 2011 mafic magma and 2018 magma, respectively. Yellow lines show CO2/H2O, CO2/S, S/H2O, and H2O/S ratios of the volcanic gases observed in 2011 (Shinohara 2013; Additional file 11). Green line in b shows CO2/S ratios of the volcanic gas observed in 2017 (GSJ/AIST 2017; Additional file 11). The same symbols are used as in Fig. 7