Whakaari/White Island: Ash emissions reduced, night glow continues

Published: Mon Sep 6 2021 3:55 PM

Volcanic Alert BulletinWI - 2021/11
Mon Sep 6 2021 3:15 PM; Whakaari/White Island Volcano
Volcanic Alert Level remains at 2
Aviation Colour Code remains at Yellow

While intermittent ash emissions have reduced since last week, the volcano remains in a moderate to heightened state of unrest. The Volcanic Alert Level remains at Level 2.

Some sustained ash emissions were observed on Thursday and Friday last week but have now decreased. While the ash was carried downwind towards the coast, no ash falls were observed on the mainland.

Persistent night glow continues to be observed on our night vision cameras, indicating high-temperature gas emissions. The volcano is emitting a lot of hot gas and steam and coupled with weather conditions, this has caused plumes to form above the island. These have been well observed from the coast.

Satellite based ground deformation measurements continue to show a broad region of subsidence around the active vents. This may be attributed to the release of pressurised gas at depth which has fed the recently observed plumes. It is likely that weak wall fragments fall into the gas stream through the active vents, leading to the reported ash emissions. We have recorded several volcanic earthquakes, but other seismic activity has been minor.

The current level of activity is consistent with moderate to heightened levels of unrest. As such the Volcanic Alert Level remains at 2 and the Aviation Colour Code remains at Yellow.

Equipment that provides real-time monitoring on the island is currently degraded and we are continuing to work on restoration options.

The Volcanic Alert Level reflects the current level of volcanic unrest or activity and is not a forecast of future activity. While Volcanic Alert Level 2 is mostly associated with volcanic unrest hazards (including discharge of steam and hot volcanic gases, earthquakes, landslides, and hydrothermal activity), potential for eruption hazards also exists and eruptions can still occur with little or no warning.

Further information about the volcanic alert levels and what they mean can be found here.

GNS Science and the National Geohazards Monitoring Centre continue to monitor Whakaari/White Island for further changes in unrest.

Yannik Behr

Duty Volcanologist

Media Contact: 021 574541 or media@gns.cri.nz