Auckland Volcano | John Seach


North Island, New Zealand

36.90 S, 174.87 E
summit elevation 260 m
volcanic field

Auckland Volcanic Field consists of 49 small basaltic volcanoes covering an area 360 sq km, covering the city of Auckland. The volcano has been active for 140,000 years, and has produced 7 cubic km of eruption products.

The Auckland volcanic field covers an elliptical area of diameters 29 km x 16.5 km. The volcano is located 400 km west of the tectonic plate boundary through New Zealand.

Rangitoto Island. Auckland's youngest volcano.

Mt Eden - crater close to Auckland CBD.

one tree hill
One Tree Hill, Auckland

Mt Mangere
Mt Mangere, Auckland

Mt Wellington
Mt Wellington, Auckland

Auckland is New Zealand's largest city. Future eruptions of the volcano may be dangerous to the population, and warning times may be limited because of the likely rapid rise of magma from mantle to surface. Magma may rise from storage to surface in less than 100 days.

Eruptions of Auckland volcano
Eruptions have ranged from phreatomagmatic (forming maars and tuff rings) to magmatic (producing lava flows and scoria cones). Some have vents have displayed more than one eruption style. Each eruption has lasted for no more than 10 years, but occasionally eruptions have lasted for 100 years.

The most recent eruption was Rangitoto, about 600 years ago. Rangitoto Island is part of the Hauraki Gulf Marine Park, 3 km offshore from Auckland. Eruptions from the island account for 59% of the eruption volume at Auckland.

Eruption frequency has been variable over the history of the volcano, but eruption magnitude has increased with time. The longest lava flow extends for 10 km and a maximum thickness of 60 m. Total surface area of lava flows is 75 sq km. Lava on Rangitoto Island covers 23 sq km.

Historically there has been a low level of seismicity at the volcano. It is anticipated that future eruptions at the volcano would be preceded by 14–90 days of seismic activity, based on experience with similar volcanoes elsewhere.

2013 Earthquakes
Two earthquakes (mag 3.9 and 3.1) hit 5 km east of Rangitoto Island on 17th March 2013.

Further reading
Linnell, T., Shane, P., Smith, I., Augustinus, P., Cronin, S., Lindsay, J. and Maas, R., 2016. Long-lived shield volcanism within a monogenetic basaltic field: the conundrum of Rangitoto volcano, New Zealand. Bulletin128(7-8), pp.1160-1172.

Rout, D.J., Cassidy, J., Locke, C.A. and Smith, I.E., 1993. Geophysical evidence for temporal and structural relationships within the monogenetic basalt volcanoes of the Auckland volcanic field, northern New Zealand. Journal of Volcanology and Geothermal Research57(1-2), pp.71-83.

Auckland Volcano Eruptions

600 years ago (Rangitoto Island).