The Kermadec Islands are a subtropical island arc in the South Pacific Ocean 800–1,000 km northeast of New Zealand’s North Island, and a similar distance southwest of Tonga. The islands are part of New Zealand, 33 km2 in total area and nowadays uninhabited, except for the permanently manned Raoul Island Station, the northernmost outpost of New Zealand.
Beneath its waters is the longest under water volcanic arc on the planet – more than 50 submarine volcanoes extending along the 2,500km collision zone between the Pacific and Australian tectonic plates. This is a place where striking volcanic landforms and incredible displays of volcanism, submarine hydorthermal venting and geomorphc features are still being discovered.
To the east of the islands, the Kermadec Trench plunges more than 10 kilometres beneath the ocean’s surface – about five times deeper than the Grand Canyon. It is the deepest ocean trench in the southern hemisphere and the second deepest on the planet.
www.thekermadecs.org is a fantastic website about the area (I would say that – I designed the website!)
The Pew Environment Group is working toward turning the region into the largest marine sanctuary on the planet.