The Bay of Plenty region contains one of New Zealand's most
important areas of potential volcanic activity, the Okataina
Volcanic Centre. Immediately southwest of the region lies the Taupo
Volcanic Centre, which links with the volcanic cones of Ruapehu and
The complete volcanic zone running from Mt Ruapehu to White
Island, 50 kilometres off the region's coastline, is called the
Taupo Volcanic Zone (TVZ). The TVZ runs straight through the centre
of the Bay of Plenty region, taking in the major urban areas of
Rotorua and Kawerau, and fringing Whakatane township.
Volcanic eruptions from within or outside the region, and
earthquakes mainly from within the Bay of Plenty region, are likely
to affect the population within any one person's lifetime.
A major historic eruption from the Okataina Volcanic Centre was
Mt Tarawera, 1886, killing over 150 of the residents of that time.
The ashfall from that eruption can still be found in the regional
soil profiles today. Soil profiles also show that much larger
eruptions have happened many times over the last 20 000
Previous eruptions are known to have been much greater in both
volume and duration. The eruption preceding the 1886 eruption,
about 1305 AD, lasted for at least four years and was approximately
four times as large. On average, major eruptions from the Okataina
Volcanic Centre occur about every 2000 years.