An apocalypse is a “very serious event resulting in great destruction and change” (according to the Cambridge Dictionary)
https://dictionary.cambridge.org/dictionary/english/apocalypse
A super volcano event possibly resulted in a human population decline of up to 90%, although a group of African early-modern humans nearly 9000kms away managed to thrive in this period, putting the whole thesis into contention.
https://www.gizmodo.com.au/2018/03/these-early-humans-prospered-during-what-should-have-been-a-devastating-volcanic-winter/
According to Yuval Harari in his book Homo Sapiens, there were six species of humans 100,000 years ago.
An article by Luke Kemp on the BBC demonstrated a complication of factors contributed to the death of ancient civilisations, including climate change and socio-economic inequity. Kemp defined collapse as a “rapid and enduring loss of population, identity and socio-economic complexity,” although a few of the civilisations in his study recovered and/or transformed.
http://www.bbc.com/future/story/20190218-are-we-on-the-road-to-civilisation-collapse
Commentaries on the war in Gaul byJulius Caesar, quoted in A History of Rome by Cary and Scullard (The Macmillan Press Ltd, 3rd Edition 1975), page 262.
Pompeii research: https://news.nationalgeographic.com/news/2010/11/101102/pompeii-mount-vesuvius-science-died-instantly-heat-bodies/
Written, edited and produced by Mark Webster, original music by kraM Left, plus self-generated & Logic Pro 12 foley, Aotearoa New Zealand 2026