What is a Volcanic Alert Level?

Published: Thu Sep 12 2019 3:00 PM

GeoNet keeps a close eye on all active volcanoes in New Zealand (and the Kermadecs). To help us do this we have the New Zealand Volcanic Alert Level System, which defines the current level of activity at each volcano.

The alert levels range from 0 to 5, where level 0 is no volcanic unrest and Level 5 is a Major Volcanic Eruption in progress. We use the NZ Volcanic Alert Level System to communicate with responding agencies, industries, media and the public about the status of the volcanoes.

Do you live near a volcano? To find out what to do before, during and after a volcanic eruption, visit Get Ready.

New Zealand Volcanic Alert Level System

New Zealand Volcanic Alert Level System

What do the various levels mean?

Levels 1 and 2 relate to volcanic unrest (the volcano is up to something that may lead to an eruption), while levels 3, 4 and 5 relate to eruptions actually happening (the exciting stuff).

Level 0 (Zero): No volcanic unrest

Level 1: We can measure signs of unrest, such as gas, earthquakes or temperature changes

Level 2: We are measuring significant changes and there is an increased eruption potential

Level 3: A small eruption is occurring, with impacts near the vent area

Level 4: A moderate eruption is in progress, with impact beyond the vent and near the volcano

Level 5: A major volcanic eruption is in progress with impact well beyond the volcano

Our volcanoes can erupt at any level, and levels may not move in sequence as activity can change rapidly.

Check out this great video showing our volcanoes at each of the alert levels:

The NZ Volcanic Alert Level system applies to all of New Zealand's active volcanoes and is set by our volcano monitoring team. Data from the GeoNet monitoring networks is used to inform the alert level decisions. Volcanoes are complex, with interactions always ongoing between the magma, gas and fluids of the geothermal systems. These interactions can produce changes that we can measure on the volcanoes e.g. volcanic earthquakes, temperature, gas and water chemistry changes. You can read more on how we monitor our volcanoes here.

How do I get this information?

You can see the current status of our volcanoes on our website. When a Volcanic Alert Level is changed we put information out in a Volcanic Alert Bulletin (VAB) this is added to our website and sent out to the GeoNet App, Facebook and Twitter accounts. If you are interested, you can read more about the volcanic alert levels and there is lots of information on volcanoes in New Zealand.

Do you have an eruption plan? Visit Get Ready.

Attributable to: Brad Scott – Volcano Information Specialist, GNS Science