> ...the long-standing belief that active volcanoes have large magma bodies that are expelled during eruptions... I'm not a geologist, and my current "knowledg

> ...the long-standing belief that active volcanoes have large magma bodies that are expelled during eruptions... I'm not a geologist, and my current "knowledge" of volcanology is mostly from the GeologyHub YouTube channel - but that is completely contrary to my understanding. If a serious magma chamber is emptied during an eruption, then the volcano above it (and some of the surrounding area) will collapse into the empty chamber. Because there's no way in hell that an empty magma chamber could support the weight of its own roof. The vast majority of volcanic eruptions - even VEI 5 ones, like Mount St. Helens in 1980 - do not work like that. The magma chamber is still there, after. It's probably shrunk a bit - volcanologists measure ground-level uplift and subsidence in centimeters, to monitor that - and is a bit depleted of volatiles (volcanic gasses, which can act a bit like the fizz in a shaken bottle of soda). That's it.