Tsunami monitoring and detection network

This page provides information about New Zealand’s tsunami monitoring and detection network.

Foreign Affairs Minister Winston Peters and Civil Defence Minister Peeni Henare have announced the deployment of a network of DART (Deep-ocean Assessment and Reporting of Tsunami) buoys. This is a significant boost to New Zealand’s end to end arrangements for monitoring, detecting and issuing warnings about tsunami.

New Zealand’s geographical and geological place in the Pacific, puts us at risk from many different tsunami sources, some may be generated and arrive at our nearest coasts in less than an hour.

The network includes a number of DART buoys, which can provide rapid confirmation if a tsunami has been generated, and will enable timelier, more accurate warnings of tsunami using public alerting systems like Emergency Mobile Alerts.

What is a DART buoy?

DART (Deep-ocean Assessment and Reporting of Tsunami) buoys are deep-ocean instruments that monitor changes in sea level. They are currently the only accurate way to rapidly confirm a tsunami has been generated before it reaches the coast.

This is about keeping people safe by giving advance notice that a tsunami is heading our way. This is particularly critical for unfelt earthquakes originating from the Kermadec trench. Early detection of a tsunami using DART buoys allows us to accurately provide early warnings using a range of communication channels including Emergency Mobile Alerts.

How do DART buoys work?

DART buoys detect tsunami threats by measuring associated changes in water pressure via sea floor sensors. They are capable of measuring sea-level changes of less than a millimetre in the deep ocean. Two-way communication between a DART buoy and a 24/7 monitoring centre allows rapid assessment and subsequent warning advice to be provided to the public.

End to end process from seafloor to tsunami warning

  1. Infographic showing Dart Buoy end to end processAn event that could trigger a tsunami such as a large undersea earthquake or undersea volcanic eruption occurs.
  2. If a tsunami is generated, there are rapid and unusual changes to the water pressure on the sea floor.
  3. The DART buoy’s sensor on the ocean floor measures water pressure.
  4. The measurements are sent by acoustic signal to a buoy on the surface.
  5. The buoy sends the signal to a satellite.
  6. The signal is sent to the 24/7 National Geohazards Monitoring Centre at GNS Science.
  7. GNS Science Geohazards Analysts analyse the data.
  8. If a tsunami has been detected the Geohazard Analyst will notify the National Emergency Management Agency, the official tsunami warning agency for New Zealand.
  9. The National Emergency Management Agency will issue a tsunami warning to CDEM Groups, emergency services, media and directly to the public via their website www.civildefence.govt.nz and Twitter @NZCivilDefence.
  10. If flooding of land areas is expected, the National Emergency Management Agency will also send an Emergency Mobile Alert to all capable mobile phones in the affected areas.

Download the How do DART buoys work infographic (.pdf 450kb)

Get tsunami ready: Know the natural warning signs and take action

For a local source tsunami, which could arrive in minutes, there won’t be time for an official warning. It is important to recognise the natural warning signs and act quickly.

If you are near a shore and experience any of the following, take action. Do not wait for official warnings.

  • Feel a strong earthquake that makes it hard to stand or a long earthquake that lasts more than a minute
  • See a sudden rise or fall in sea level
  • Hear loud or unusual noises from the sea

Drop, Cover and Hold during the shaking. Protect yourself from the earthquake first.

As soon as the shaking stops, move immediately to the nearest high ground, out of all tsunami evacuation zones, or as far inland as you can.

Remember: Long or Strong, Get Gone.

Get Ready: Find out more about tsunami

NZ DART Buoys - tsunami detection technology