Bay of Plenty Times
  • Bay of Plenty Times home
  • Latest news
  • Business
  • Opinion
  • Lifestyle
  • Property
  • Sport
  • Video
  • Death notices
  • Classifieds

Subscriptions

  • Herald Premium
  • Viva Premium
  • The Listener
  • BusinessDesk

Sections

  • Latest news
  • On The Up
  • Business
  • Opinion
  • Lifestyle
  • Property
    • All Property
    • Residential property listings
  • Rural
    • All Rural
    • Dairy farming
    • Sheep & beef farming
    • Horticulture
    • Animal health
    • Rural business
    • Rural life
    • Rural technology
  • Sport

Locations

  • Coromandel & Hauraki
  • Katikati
  • Tauranga
  • Mount Maunganui
  • Pāpāmoa
  • Te Puke
  • Whakatāne
  • Rotorua

Media

  • Video
  • Photo galleries
  • Today's Paper - E-Editions
  • Photo sales
  • Classifieds

Weather

  • Thames
  • Tauranga
  • Whakatāne
  • Rotorua

NZME Network

  • Advertise with NZME
  • OneRoof
  • Driven Car Guide
  • BusinessDesk
  • Newstalk ZB
  • Sunlive
  • ZM
  • The Hits
  • Coast
  • Radio Hauraki
  • The Alternative Commentary Collective
  • Gold
  • Flava
  • iHeart Radio
  • Hokonui
  • Radio Wanaka
  • iHeartCountry New Zealand
  • Restaurant Hub
  • NZME Events

SubscribeSign In
Advertisement
Advertise with NZME.
Home / Bay of Plenty Times

Deep pool of magma caused Bay earthquakes

Sonya Bateson
By Sonya Bateson
Regional content leader, Bay of Plenty Times and Rotorua Daily Post·Bay of Plenty Times·
3 Jun, 2016 10:43 PM2 mins to read

Subscribe to listen

Access to Herald Premium articles require a Premium subscription. Subscribe now to listen.
Already a subscriber?  Sign in here

Listening to articles is free for open-access content—explore other articles or learn more about text-to-speech.
‌
Save

    Share this article

A swarm of earthquakes in Matata between 2004 and 2011 was caused by the growth of a magma chamber under the coast, GNS Science has revealed.

Scientists used a combination of satellite images, GPS data and conventional survey information dating back to the 1950s to uncover the reason for the swarm of several thousand small earthquakes over that period around the coastal Bay of Plenty town.

The three streams of data showed that an area of land around Matata - roughly 20km by 20km, about half of which is offshore - had been pushed up by about 40cm since 1950.

Until now the cause of the swarm was thought to be tectonic.

The new finding concluded the swarm was caused by the growth of a previously unrecognised magma chamber under the Bay of Plenty coast.

Advertisement
Advertise with NZME.
Advertisement
Advertise with NZME.

During this period, molten or semi-molten rock was being pushed up from below and caused land around Matata to uplift by about 1cm a year. As the magma moved in the sub-surface, it caused the surrounding rock to deform and break, resulting in small earthquakes.

Using modelling, scientists concluded a magma body lies about 9km below the surface. Since 1950, it has grown in volume by 0.2 cubic kilometres, or equivalent in size to about 80,000 Olympic swimming pools.

Scientists say the presence of a magma body does not mean an eruption might be imminent and it has not changed the volcanic hazard of the Bay of Plenty region.

Advertisement
Advertise with NZME.

The research has just been published in the science journal Science Advances.

Lead author Ian Hamling, a satellite image specialist at GNS Science, said the finding highlighted that accumulation of magma was not always where we might expect, based on the location of volcanoes at the surface.

"Our modelling points to the presence of a magma chamber in an area where there has been no active volcanism for about 400,000 years," Dr Hamling said.

He added that bodies of magma were reasonably common under large areas of the central North Island, and identifying another magma accumulation was not a huge surprise. "There is every possibility the magma body under the Bay of Plenty coast had been there for centuries, and possibly even longer."

Save

    Share this article

Latest from Bay of Plenty Times

live
Bay of Plenty Times

Fibre outage and evacuations top of South Island, Auck Harbour Bridge hit by high winds

02 Jul 08:39 PM
Bay of Plenty Times

'Scary stuff': Locals on crash corner fear it will take a death to get it fixed

02 Jul 06:06 PM
Bay of Plenty Times

Bike racks back for Rotorua buses, Tauranga's a month away

02 Jul 11:55 AM

There’s more to Hawai‘i than beaches and buffets – here’s how to see it differently

sponsored
Advertisement
Advertise with NZME.

Latest from Bay of Plenty Times

Fibre outage and evacuations top of South Island, Auck Harbour Bridge hit by high winds
live

Fibre outage and evacuations top of South Island, Auck Harbour Bridge hit by high winds

02 Jul 08:39 PM

Rain started falling at the top of the country before dawn.

'Scary stuff': Locals on crash corner fear it will take a death to get it fixed

'Scary stuff': Locals on crash corner fear it will take a death to get it fixed

02 Jul 06:06 PM
Bike racks back for Rotorua buses, Tauranga's a month away

Bike racks back for Rotorua buses, Tauranga's a month away

02 Jul 11:55 AM
NZ e-bike brand shines at Eurobike global showcase

NZ e-bike brand shines at Eurobike global showcase

02 Jul 03:13 AM
From early mornings to easy living
sponsored

From early mornings to easy living

NZ Herald
  • About NZ Herald
  • Meet the journalists
  • Newsletters
  • Classifieds
  • Help & support
  • Contact us
  • House rules
  • Privacy Policy
  • Terms of use
  • Competition terms & conditions
  • Our use of AI
Subscriber Services
  • Bay of Plenty Times e-edition
  • Manage your print subscription
  • Manage your digital subscription
  • Subscribe to Herald Premium
  • Subscribe to the Bay of Plenty Times
  • Gift a subscription
  • Subscriber FAQs
  • Subscription terms & conditions
  • Promotions and subscriber benefits
NZME Network
  • Bay of Plenty Times
  • The New Zealand Herald
  • The Northland Age
  • The Northern Advocate
  • Waikato Herald
  • Rotorua Daily Post
  • Hawke's Bay Today
  • Whanganui Chronicle
  • Viva
  • NZ Listener
  • Newstalk ZB
  • BusinessDesk
  • OneRoof
  • Driven Car Guide
  • iHeart Radio
  • Restaurant Hub
NZME
  • About NZME
  • NZME careers
  • Advertise with NZME
  • Digital self-service advertising
  • Book your classified ad
  • Photo sales
  • NZME Events
  • © Copyright 2025 NZME Publishing Limited
TOP