The Auckland Volcanic Field is made up of over 50
separate volcanoes scattered across New Zealand’s largest city. It is an
area of about 360 km2
During the 250,000 years, Auckland’s volcanoes have
totally changed the landscape. Volcanoes in Auckland include small cones
less than 150 m in height and explosion craters.
The AVF is made up of around 53 hotspot
volcanoes of various sizes and ages.
Remember hotspot volcanoes are made up of
basaltic lava. They usually only usually erupt
once.
The type of volcanic activity in Auckland means
each eruption has occurred at a new location; these are coming from a
single active ‘hot spot’ of magma about 100 km below the city. Many of
the volcanoes today have been quarried or become public parks.
Auckland’s existing volcanoes are unlikely to
become active again, but the Auckland Volcanic Field itself is
young and still active. Any new explosions would occur from
entirely new vents
Rangitoto
The most recent eruption occurred around 600
years ago at Rangitoto
Of all Auckland’s eruptions, Rangitoto was
the only one witnessed by people.
The eruption would have been extremely
violent, as the lava came into contact with sea water.
Rangitoto alone produced a volume of lava
equal to that erupted by the rest of the volcanoes in the volcanic
field.
Auckland is vulnerable to ash fall
from other North Island volcanoes. As Auckland provides over 1/3 of the
nation’s gross domestic product, is a major transport and economic hub,
and is home to over 1.6 million people, a volcanic eruption would
place the nation’s economy and the city’s infrastructure and population
at risk.
DEVORA project (Determining Volcanic Risk in
Auckland) is working on a 7 year project around the risks of the
AVF