Eruption of Mount Kantmai

Geological / environmental event

A long-dormant volcano chain to the west of the Aquimore Empire erupts at the same time as multiple earthquakes hit the area.

In the Month of Light, Mount Kantmai erupts at the same time as the Continent and surrounding areas are hit by multiple earthquakes. The ash from the resulting eruptions blankets the entire world and blocks out the sky, sending the world into an early winter.
As the ash begins to disperse over the next month, the Brosha Islands and Estrea are hit by tidal waves. Alpta is hit by storms of black ash-filled hail. Despite a third of Eilt Un being submerged in rising tides, the people escape relatively unharmed due to their almost exclusively living on boats.
Widespread panic across the Continent ensues, with an increased spike in Qhil worship, as hundreds beg the ocean for forgiveness of unknown transgressions.