An afterclap is a sudden unexpected event or repercussion, or something which occurs after an event is supposed to have ended.
Matthew's sudden disappearance was caused by an unknown event or circumstance that affected him.
sudden and unexpected or brief to the point of rudeness or steep; precipitous
catastrophe
I think it's extinction. ------------------------------- More specifically an "extinction event".
catastrophe =katastrofeMeaning an event causing great and sudden suffering.
Sudden impact.
an ice age
Some event that is usually sudden and unexpected that requires immediate action to rectify.
an event causing great and often sudden damage or suffering; a disaster
Pre- means before. Ictus means a sudden event such as a stroke, seizure, collapse, or faint So, Pre-Ictus is the period before such an event.
A catastrophic event is basically the same as a sudden natural disaster - flood, earthquake, tsunami, etc. especially if there is a considerable loss of life, and damage to property.