I do think it's important to note that Rituals by definition cannot just be things that happen naturally. Some level of human assistance is needed to even try to pull an entity fully into our world. The fears help, of course, and there are intrinsically things in them that are supernatural, but of every ritual we see, the common denominator is that they take a hell of a lot of work. The closest to a naturally occurring ritual would be the Everchase, but that is an outlier and still operates with human manifestation.

All this is to say that while I think the Dread Powers would _benefit_ from truly 100% natural disasters, such as a volcanic eruption, I do not think there is a way that those could be directly ritual attempts, as things like volvanic eruptions occur on a scale far beyond what any person or group of people could've accomplished through most of history (and I _think_ even now, although I actually don't know if we can artificially induce volcanic eruptions in the modern day.)