Taupo Volcanic Zone - Extent and Geological Context

Extent and Geological Context

The Taupo Volcanic Zone is approximately 350 kilometres (217 mi) long by 50 kilometres (31 mi) wide. Mount Ruapehu marks its southwestern end, while the submarine Whakatane volcano (85 kilometres (53 mi) beyond White Island) is considered its northeastern limit.

It forms a southern portion of the active Lau-Havre-Taupo back-arc basin, which lies behind the Kermadec-Tonga subduction zone. Volcanic activity continues to the north-northeast, along the line of the Taupo Volcanic Zone, through several undersea volcanoes (known as Clark, Tangaroa, the Silents and the Rumbles), then shifts eastward to the parallel volcanic arc of the Kermadec Islands and Tonga. Although the back-arc basin continues to propagate to the southwest, with the South Wanganui Basin forming an initial back-arc basin, volcanic activity has not yet begun in this region. The Taupo Volcanic Zone can therefore be seen as the southwestern end of the Pacific Ring of Fire, which marks out the subduction zones around the Pacific Ocean.

South of Kaikoura the plate boundary changes to a transform boundary with oblique continental collision uplifting the Southern Alps in the South Island. A subduction zone reappears southwest of Fiordland, at the southwestern corner of the South Island, although here the subduction is in the opposite direction. Solander Island is an extinct volcano associated with this subduction zone, and the only one that protudes above the sea.