Whakaari/White Island: Elevated volcanic unrest continues

Published: Thu Apr 16 2020 10:30 AM

Volcanic Alert BulletinWI – 2020/07
Thu Apr 16 2020 10:00 AM; Whakaari/White Island Volcano
Volcanic Alert Level remains at 2
Aviation Colour Code remains at Yellow

Whakaari/White Island remains in an elevated state of unrest. No significant changes in the amount of volcanic gas emitted or seismic activity were recorded in March-April. The Volcanic Alert Level remains at Level 2; Aviation Colour Code remains at Yellow.

During lockdown (COVID-19 Level 4), we have continued the monitoring of Whakaari/White Island with the instrumentation that automatically sends us data. These are primarily the seismic and SO2 gas sensors data, and images from our web cameras. Over the weekend there were public reports of heightened steam activity, but we can confirm there were no eruptions; just the nice weather allowed people to better see the volcanic gas plume. We have not conducted further aerial-based measurements and observations of the volcano in the past three weeks.

The remotely transmitted gas data from the sensors suggests no significant changes in SO2 output compared with what we saw in March. The volcano continues to emit SO2 gas, which is derived from magma (molten rock at shallow depth), and is one of our main indicators of volcanic unrest. Emission rates for other gases have not been measured over the past few weeks as we scaled down non-essential field visits during the COVID-19 lockdown. Seismic activity remains at lower levels and continues to fluctuate over periods of hours or days.

Although the web cameras are still partially covered by ash from the December eruption, and in need of a clean, the recent rain has helped. The layout of the active vent areas appears to be mostly unchanged since early March. We continue to see evidence of high temperatures at night, but no changes in the locations of these heat sources are apparent.

The active vent area remains a dynamic environment and an eruption could occur with little precursory activity. Plausible triggers for an eruption remain the collapse of unstable material around the vents, sudden release of gas from the magma, and the rapid ingress of water onto the shallow magma body.

Should any explosive activity produce an ash cloud, the likelihood of ash affecting the mainland remains very low. Under suitable weather conditions, the gas and steam plume may be noticed on the mainland as weak acid rain.

The Volcanic Alert Level remains at Level 2.

The Aviation Colour Code remains at Yellow.

Volcanic Alert Level 2 indicates moderate to heightened unrest with potential for eruption hazards, including unpredictable and life-threatening steam driven eruptions.

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. Further updates will be provided as needed.

Steven Sherburn

Duty Volcanologist

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