Fig. 3: Melt fraction modeling based on two-phase differential effective medium theory49.

Vp = 6.4 km/s, Vs = 3.5 km/s and density = 2.97 g/cm3 for solid basalt, and Vp = 2.35 km/s, Vs = 0 km/s and density = 2.7 g/cm3 for basaltic melt5. Black dashed line denotes spherical inclusions (aspect ratio of 1), and red, blue and green dashed lines are for vertically aligned elliptical melt inclusions with aspect ratios of 0.5, 0.1, and 0.02, respectively. Purple, orange, and gray shaded regions indicate the melt extent for the upper main magma reservoir (MMR), lower MMR, and feeding conduit.