Tongariro Massif is a complex arrangement of cones - some
eroded by the ice age 6500 years ago, and some formed since. The
most recent vent of Tongariro is Mt. Ngauruhoe.
has been considerable activity from Tongariro in the last
2000 years, since 1855 there have been several eruptions from
the Upper Te Maari Crater and the Red Crater. There is a continuous
steam discharge from Ketetahi on the northern face of Tongariro.
Ketetahi releases about the same energy as the Wairakei Geothermal
Power Station in Taupo which supplies 3% of New Zealand's electricity.
are a dozen craters on Tongariro. The Northern Crater -
the biggest crater - is a kilometer across. Some of the explosion
pits on Tongariro have filled with water, giving a brightly
coloured contrast to the surrounding landscape. Activity from
Ketetahi and the Red Crater has been continuous since observation