Volcanoes in New Zealand

The New Zealand area is characterised by both a high density of active volcanoes and a high frequency of eruptions. Volcanic activity in New Zealand occurs in six areas (see figure below), five in the North Island and one offshore in the Kermadec Islands.Volcanoes in New Zealand are not randomly scattered, but are grouped into areas of more intensive and long-lived activity, whose position (and the composition of the lavas erupted) can be related to the large-scale movement of the tectonic plates in the New Zealand region. Most New Zealand volcanism in the last 1.6 million years has occurred in the Taupo Volcanic Zone (TVZ). The zone is an elongate area that extends from White Island to Ruapehu. The Taupo Volcanic Zone is extremely active on a world scale: it includes three frequently active cone volcanoes (Ruapehu, Tongariro/Ngauruhoe, White Island), and two of the most productive calderas in the world (Okataina and Taupo).Volcanic Fields

Volcanic fields such as Auckland and Northland, are where small eruptions occur over a wide geographic area, and are spaced over long periods of time (thousands of years). Each eruption builds a new single new volcano, which does not erupt again. Mount Eden and Rangitoto Island are examples in Auckland.

Cone Volcanoes

Cone volcanoes such as Ruapehu, Egmont and Ngauruhoe are characterised by a succession of small-moderate eruptions from one location. The products from the successive eruptions over thousands of years build the cones.

Caldera Volcanoes

Caldera volcanoes such as Taupo and Okataina (which includes Tarawera) have a history of infrequent but moderate-large eruptions. The caldera forming eruptions create super craters 10-25 km in diameter and deposit cubic kilometres of ash and pumice.