AT 2518 metres, Mount Taranaki is the imposing presence in its namesake province … yet it used to be significantly taller still.

What cut the conical mountain down to modern size was what is known as a volcanic debris avalanche, a truly cataclysmic event when it occurred.

At least 7.5 cubic kilometres – yes, kilometres – of debris crashed off Taranaki Maunga’s north-western slopes, covering up to 250 square kilometres of land with material up to 30 metres deep. All the way to the coastline.