Auckland Volcanic Field

Extreme Earth Events - 12ESS

Finn LeSueur

2021

Ngā Whāinga Ako

  1. Identify the main volcanoes in the Auckland Volcanic Field
  2. Describe how each of these volcanoes form
  3. Identify the key features of each volcano type

Write the date and ngā whāinga ako in your book

Auckland Volcanic Field

Source
  • 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.
Source

Risks of the AVF

  • 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
1991 Pinatubo Eruption (Source)

Task/Ngohe

  1. Collect your workbook from the cupboard
  2. Find the section on Auckland
  3. Complete the reading and questions