The ice age began 2.6 Ma , at the start of the Pleistocene epoch , and is defined by the presence of ice sheets on Greenland and Antarctica . During the warmer periods sea level was higher than today leading to raised beaches around New Zealand . New Zealand 's flora is still recovering from the last glacial maximum . About 2 Ma , extension and subduction under the North Island formed the Taupo Volcanic Zone . Leading to the central North Island being covered in cobalt deficient soils which restrict forest development . One of the largest eruptions being the Lake Taupo eruption of 186 AD
Lake Taupo eruption
Hatepe eruption
Natural history of New Zealand