Something massive and disastrous happens! Catastrophe can be anything from a massive meteor coming down and obliterating a city to a devastating plague or a flood of hungry ghosts. However, no matter what form it takes, its impact is massive.
Mechanically, Catastrophe can affect the same area as other abilities such as shape land when affecting objects on the map, these changes can mimic multiple other abilities at the same time (such as shaping the land, corrupting it and shaping the climate around it as a single action). In addition, it may be used for other effects such as the destruction of advancements, the death of avatars and the collapse of societies. The possibilities are nigh limitless, so feel free to come up with anything you like. However, the game moderator has the right to veto the action if it is deemed too disruptive to the rest of the game.