Rhyolitic lava domes were extruded some years or decades later, forming the Horomatangi Reefs and Waitahanui Bank.

[7] The main extremely fast moving pyroclastic flow travelled at close to the speed of sound and devastated the surrounding area, climbing more than 1,500 m (4,900 ft) to overtop the nearby Kaimanawa Ranges and Mount Tongariro, and covering the land within 80 km (50 mi) with ignimbrite.

[6] The eruption column penetrated the stratosphere as revealed by deposits in ice core samples in Greenland and Antarctica.

[6] There were massive changes in the landscape for 40 km (25 mi) around with all life sterilised and prior landforms evened out, with beyond the ignimbrite sheet likely forest fires and ash associated die back especially to the west.

[6] In 1937 it was recognised that the deposit from the Hatepe eruption had been so hot to burn the forest at a 160 km (99 mi) distance from Lake Taupō, but this was not understood as being due to a pyroclastic flow until 1956.

The previous outlet was blocked, raising the lake 35 meters (115 feet) above its present level until it broke out after about 20 years in a huge flood.

[18] However, rhyolitic shards derived from the Taupo eruption have been identified in the Roosevelt Island ice core and are independently dated to 230 CE ± 19, thus refuting propositions of a potential age bias.