Whakaari/White Island eruption: Update #17

Published: Mon Dec 23 2019 1:50 PM

Volcanic Alert BulletinWI – 2019/29
Mon Dec 23 2019 1:10 PM; Whakaari/White Island Volcano
Volcanic Alert Level remains at 2
Aviation Colour Code remains at Orange

Very hot gas and steam continue to be discharged from active vents at the back of the crater basin. Volcanic tremor and other seismic activity continue at a low level. Further eruptions are very unlikely in the next two weeks. The Volcanic Alert Level remains at Level 2.

Since the eruption on Monday December 9th, no further eruptive activity has occurred. The level of volcanic tremor and other seismic activity remains low, but strong flows of steam and gases continue from the new vent area.

The expert judgement made this morning calculated the likelihood of another eruption occurring between now and midday Monday January 6th. This judgement translates to another eruption being very unlikely (2 - 10%) within any 24-hour period through to midday Monday January 6th. Consequently, the distances for GNS Science staff access zones have been reduced, but remain too large for GNS Science staff to access the island. The expert judgement will be reviewed again on Monday January 6th, or sooner if the level of activity changes.

An explosive eruption from the hot gas vent area remains possible and could occur with no precursory activity, especially if there is a collapse of unstable material around one of the vents, or if the gas emission decreases markedly, allowing water to enter the hot gas vent. Sudden steam/gas eruptions from other active vents are also possible.

Should any explosive activity produce an ash cloud there remains a low likelihood of ash affecting the mainland in the next week.

All our monitoring equipment on the island is operating, except for the camera at the old factory site.

The Volcanic Alert Level remains at Level 2.

The Aviation Colour Code remains at Orange.

Volcanic Alert Level 2 indicates moderate to heightened unrest with potential for eruption hazards.

The Volcanic Alert Level reflects the current level of volcanic activity and is not a forecast of future activity.

GNS Science and our National Geohazards Monitoring Centre continue to closely monitor Whakaari/White Island for further signs of activity. We are providing updates on the volcanic activity and estimates of eruption likelihood as required to support operations.

Enquiries related to the emergency response should be directed to National Emergency Management Agency (NEMA).

More information will be made available on Monday January 6th, or sooner if required.

Steve Sherburn

Duty Volcanologist

Media Contact: 021 574 541 or media@gns.cri.nz