Fig. 2
Relationships among non-dimensional parameters ε and θ and porosity (Φ) for n0= 0.04 and T = 1123 (K) on the basis of Eq. (10). (a) Results for P = 0.1 (MPa); (b) results for P = 10 (MPa). Possible ranges of ε and θ estimated from typical values of µ, k, rc, q and Φ for actual dome-forming eruptions (µ = 1011–1014 Pa s for (a) and 105–108 Pa s for (b), k = 10−14-10−12 m2, rc = 10–50 m, q = 0.1–10 kg m−2 s−1 and Φ = 0.1–0.8) are also shown (dashed squares). The range of µ for (a) is estimated from the viscosities of lava domes under dry conditions (Kozono and Koyaguchi, 2009b); the range of µ for (b) is estimated to cover both the viscosities at the magma chamber (Kozono and Koyaguchi, 2009b) and the viscosity at P = 10 (MPa) using Eq. (16). See Eqs. (11) and (12) for the definitions of ε and θ, respectively.