Volcanic Alert Level

In New Zealand, Volcano Alert Bulletins (VABs) are the official source of warnings and alerts including current Volcanic Alert Level (VAL),^[1] intended to inform stakeholder agencies, authorities, and the public about emergencies so they can take action.

The Ministry of Civil Defence & Emergency Management, through The National Emergency Management Agency is responsible for providing such alerts to warn about natural hazards.^[2] A Scientific Alert Level is applied to the Volcano Status based on Indicative Phenomena. GNS Science operates the national geological hazards monitoring network (GeoNet).^[3]

Levels

The Volcanic Alert Level system has six levels ranging from 5 (major volcanic eruption) to 0 (no volcanic activity):^[4]

Volcanic Alert Level	Volcanic Activity	Most likely hazards	Example
5	Major volcanic eruption	Eruption hazards on and beyond volcano	–
4	Moderate volcanic eruption	Eruption hazards on and near volcano	2019 Whakaari / White Island eruption
3	Minor volcanic eruption	Eruption hazards near vent	–
2	Moderate to heightened volcanic unrest	Volcanic unrest hazards, potential for eruption hazards	Whakaari / White Island in 2019 before eruption[5][6]
1	Minor volcanic unrest	Volcanic unrest hazards	–
0	No volcanic unrest	Volcanic environment hazards	–

Elsewhere

To help prevent harm when living or working on or near a volcano, countries have adopted classifications to describe the various levels and stages of volcanic activity, the two main volcano warning systems being colour codes and/or numeric alert levels. ^[7]

• United States Alert System
• Indonesia Alert System ^[8]
• Russia
• Alaska Alert System
• Vanuatu Volcanic Alert Level
• Colombia Alert System ^[7]

The three common popular classifications of volcanoes can be subjective, and some volcanoes thought to have been extinct have erupted again.