The precise nature of the cataclysm is unknown, although its descriptions and effects resemble those of an earthquake or volcanic eruption of some kind.
The cataclysm buried most Elderling cities in the Rain Wilds and altered the course of the Rain Wild River. It also altered the coastline of the Cursed Shores. The frequent earthquakes that affect the Rain Wilds are thought to be a lingering effect of the cataclysm.
The cataclysm had a profound effect on the dragon species. Although many serpents survived the event, the changes to the coastline meant that many were unable to identify their migration path. Those who did find the Rain Wild River died while attempting to swim upstream, either due to the river's altered course or the destruction of former cocooning grounds. Because of this, the serpent population dwindled, and those who survived began to lose their ancestral memories.
When the cataclysm struck, several dragon cocoons were rescued and sheltered within the Crowned Rooster Chamber of Frengong. When discovered by the Rain Wild Traders of Trehaug centuries later, they were mistaken for logs of wood. Split open and made into planks, the cocoons were used to create sentient liveships; this resulted in the death of the dragon hatchling within the cocoon.
The only full-grown dragon known to have survived the cataclysm is Icefyre, who believed his species extinct after the event and flew to Aslevjal to die. The only cocooned dragon to have survived is Tintaglia, who hatched from her intact cocoon with the assistance of Malta Vestrit, Selden Vestrit, and Reyn Khuprus. A large number of serpents survived the cataclysm, but the only few to have eventually migrated successfully up the Rain Wild River were those who comprised Maulkin's Tangle.