I'm really sorry. It was not much. On his Sunday show, I would guess 5 weeks ago. Someone, maybe Lucas, was on and he just said in an offhand way that Etna has always been showing activity but when it finally blows, the NM will be next. The way he said it made it sound like it had been something he and the guest already discussed. I spent a lot of time trying to find the original (or just a deeper) discussion of that. Particularly what he thought the mechanics were. Like if it was general or specific (i.e., when Etna goes big-time it will signify that the Earth is destabilizing enough to set off all kinds of major activity vs. a specific plate connection between these two distant regions). Unfortunately, I have never located the larger discussion.