Oruanui eruption
26000 BCE.
Shown on the map at -38.800°, 175.900°.
The Oruanui eruption (also known as the Kawakawa eruption or Kawakawa/Oruanui event) of Taupō Volcano in New Zealand around 25,700 years before present was the world's most recent supereruption, and its largest phreatomagmatic eruption characterised to date.
Text from the Wikipedia article Oruanui eruption, licensed CC BY-SA 4.0.