Born to Love Volcanoes

My favourite part of the rapture index is #36: Volcanoes. Freud thought that Yahweh started out as a tribal volcano god, so these majestic lava spewers might be a fitting index of Biblical prophecy after all. But, if people are going to use natural phenomena as a measure of how close we are to the apocalypse, why not choose butterflies or spawning salmon? Why stop at volcanoes?