Abstract Melt inclusions readily rupture and form gas bubbles during explosive volcanic eruptions, but their role as a source remains enigmatic. Here, we examined pumice texture generated by the instantaneous bursting of melt 946 CE Plinian eruption at Baekdusan. The burst produced non-sheared, super-vesicular (>80 vol.% voids) bubble pockets, occupying volume fractions 6–24% within Millenni...