Jun 8 2000, 4:00 pm - White Island Volcano

Staff from the Institute of Geological & Nuclear Sciences (GNS) visited White Island today to assess the volcano status and do routine seismograph maintenance. The level of activity was similar to that reported over the last two months. Minor eruptive activity continues from MH vent. The Alert Level remains at 2. The hazard posed by the current eruptive activity continues.

On Thursday June 8, MH vent was producing a weak gas and ash plume. The plume was rising to 2500 – 3000 feet (800 - 1000 m) before being blown to the north-northwest. The plume was visible 20 - 30 kilometres from the island as a lightly coloured haze.

The level of seismic activity at White Island has declined almost to background levels. Seismicity started to increase about April 5, reached a peak about May 12, and has been declining since then. Although seismicity is now close to background levels, the nature and intensity of the eruptive activity has not changed significantly, confirming earlier assessments that there is no direct relationship between the intensity of the eruptive activity observed at MH vent and the level of seismic activity.

White Island has now been at Alert Level 2 for almost 50 days. Although the intensity has varied slightly with time, ash emission has occurred almost continuously during this period. Fresh ash now covers the island at a thickness ranging from several millimetres to several centimetres. The style of eruptive activity has not changed during this time. The height of the ash and steam plume has varied with eruption intensity and wind strength, but 2500 – 3000 feet (800 - 1000 m) has been typical.

The current activity is not an immediate hazard to visitors to White Island. However, past activity indicates that significantly larger eruptions, some ejecting large rocks over the island, could occur with little or no warning. Such larger eruptions would pose a significant hazard to anyone on the island at the time. Caution should be exercised when visiting the island.

GNS volcanologists will continue to closely monitor activity at White Island and further updates will be issued as necessary.

The continued minor eruptive activity confirms that the Alert Level remains at 2.

Steven Sherburn
Duty Volcanologist