Ngauruhoe (7,500 ft) has an almost perfect cone rising 3,000 ft above the southern slopes of Tongariro. In the recent past it has been the most continuously active of New Zealand volcanoes. Eruptions from this mountain were regarded by the Maori as a sign of war. Except on the east, young lava flows have reached its base on all sides and these have a loose, rugged, clinkery surface. Since 1839 considerable changes have occurred within the crater. The more notable eruptions were in 1841 with ash eruption which truncated the top, in 1855 when the west side of crater wall collapsed, in 1859 when the east wall of crater collapsed, in 1870 with ash eruption and lava flow, in 1949 with ash eruption and lava flow, and in 1954–55 again with ash eruption and lava flow.
The mountain was first climbed by J. C. Bidwill in March 1839, the ascent being from the north-west. He reported that “The crater was the most terrific abyss I ever looked into or imagined … it was not possible to see above 10 yards into it from the quantity of steam which it was continually discharging”.
Ngauruhoe, together with the other peaks of Tongariro National Park, was regarded as highly tapu by the Maori.
The name Ngauruhoe – the peak of Uruhoe –commemorates the slave whom Ngatoroirangi, archpriest of Arawa canoe, sacrificed in order to add mana to his plea for fire to be sent from Hawaiki. When this arrived, Uruhoe's body was flung into the crater that bears his name.
by Thomas Ludovic Grant-Taylor, M.SC., New Zealand Geological Survey, Lower Hutt.