27 Aug 2015

Volcanic Hazard at Mt Taranaki

From Our Changing World, 9:20 pm on 27 August 2015
Mt Taranaki is one of New Zealand's most distinctive volcanoes.

Mt Taranaki is one of New Zealand's most distinctive volcanoes. Photo: Andy Reisinger

Mt Taranaki, the second-highest mountain in the North Island, has a  classic cone shape, which indicates that it is an active volcano. Detailed studies by scientists at Massey University have worked out the history of Mt Taranaki's volcanic eruptions over the last 130,000 years. The team found that while eruptions have not occurred at regular intervals, on average there has been a moderate-sized eruption every 340 years, with numerous small ones.

Rafael Torres-Orozco at his study site.

Rafael Torres-Orozco at his study site. Photo: RNZ / Ruth Beran

Mt Taranaki last erupted around 1854, at the culmination of several eruptions in the preceding few hundred years. The western side of the Taranaki region is a volcanic landscape, constructed from the products of eruptions. On three occasions, twice within a very short period of geological time, former cones have collapsed to the north-east, south-east and the west. In each instance extremely large volumes of material flowed more than 40 kilometres across the landscape, reaching the present Taranaki coastline. They have created the distinctive mounds or hummocks on the lowlands surrounding the volcano.

Geologists think of Mt Taranaki as a "slumbering" volcano - active, in a state of quiescence, but certainly not extinct.

Any future eruptions could bring ground-hugging lava flows and landslides or more volatile explosions of ash and pumice. To find out more, Ruth Beran meets Massey University PhD student Rafael Torres-Orozco at his study site below the Curtis Ridge to talk about Mt Taranaki’s volcanic history, its potential for future eruptions and the damage that it could cause.