Thanks so much for this explanation! And the links you provided have more information than last I looked into it. (Though I don’t have access to the paper after leaving academia, I can probably get it.)

I have a couple stories about the 1937 eruption and they have oral history of older eruptions as well. It’s really interesting to me to understand more of the science behind the volcanos. Cheers!

After your explanation, I’m curious about what might be going on when two nearby volcanoes erupt at the same time. For example, I do fieldwork near Rabaul, Papua New Guinea. Though it’s before my time, I believe the eruption of Tavurvur (which destroyed much of Rabaul at the time) in 1994 (the exact date might be off) also had another eruption of a possibility new volcano nearby (my offhand guess is ~50-100km away).

I know that Tavurvur and the newer volcano are both on the rim of a much, much older caldera, which now makes up Ataliklikun Bay. So I’m wondering then, is it likely that they have the same magma chamber and the release at Tavurvur wasn’t enough to hold the pressure, and a new opening was needed?

To be honest, I may have some small details a bit off about this event. I’m a linguist not a geologist or volcanologist. This is all from what I remember reading and talking to people about. I had always assumed they had the same magma chamber, but I actually know nothing about how it works, and your comment had me wondering. FWIW, Tavurvur (and not the other volcano) has been active on and off again for quite awhile now (though it’s been about 10 years since I was last there, and I’m unsure of the current situation).

TIA