In New Zealand, we use a system of Volcanic Alert Levels to define the current status of each volcano. The alert levels range from 0 to 5. The alert levels are used to guide any appropriate response.


Brad Scott and Sally Potter explain New Zealand's Volcanic Alert Levels.

New Zealand Volcanic Alert System



Volcanic Activity

Most Likely Hazards



Major volcanic eruption

Eruption hazards on and beyond volcano*


Moderate volcanic eruption

Eruption hazards on and near volcano*


Minor volcanic eruption

Eruption hazards near vent*



Moderate to heightened volcanic unrest

Volcanic unrest hazards, potential for eruption hazards


Minor volcanic unrest

Volcanic unrest hazards



No volcanic unrest

Volcanic environment hazards

An eruption may occur at any level, and levels may not move in sequence as activity can change rapidly.

Eruption hazards depend on the volcano and eruption style, and may include explosions, ballistics (flying rocks), pyroclastic density currents (fast moving hot ash clouds), lava flows, lava domes, landslides, ash, volcanic gases, lightning, lahars (mudflows), tsunami, and/or earthquakes.

Volcanic unrest hazards occur on and near the volcano, and may include steam eruptions, volcanic gases, earthquakes, landslides, uplift, subsidence, changes to hot springs, and/or lahars (mudflows).

Volcanic environment hazards may include hydrothermal activity, earthquakes, landslides, volcanic gases, and/or lahars (mudflows).

*Ash, lava flow, and lahar (mudflow) hazards may impact areas distant from the volcano.

This system applies to all of New Zealand's volcanoes. The Volcanic Alert Level is set by GNS Science, based on the level of volcanic activity. For more information, see for alert levels and current volcanic activity, for volcanic hazards, and for what to do before, during and after volcanic activity. Version 3.0, 2014.

  File Modified
PDF File VAL_system-v3.0_purple.pdf The New Zealand Volcanic Alert System (official graphic, suitable for printing). May 19, 2014 by Kevin Fenaughty

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