Continued heat flow and changes in gas composition indicate increased unrest at Whakaari/White Island. Volcanic Alert Level raised to Level 2.

Published: Mon Jul 26 2021 2:30 PM

Volcanic Alert BulletinWI – 2021/07
Mon Jul 26 2021 1:30 PM; Whakaari/White Island Volcano
Volcanic Alert Level is raised to 2
Aviation Colour Code is raised to Yellow

Persistent observations of night glow on the web cameras indicate continued emission of high-temperature gases. Continued decline of the carbon dioxide to sulphur dioxide ratio points to ongoing degassing of fresh magma. The Volcanic Alert Level has been raised to 2 and the Aviation Colour Code to Yellow. This also acknowledges the uncertainty about what is driving current activity at the volcano.

Elevated levels of gas emissions continue but the ratio of carbon dioxide to sulphur dioxide has decreased. A more detailed evaluation of this observation supports the presence of magma at shallow depth.

Last week’s observation and thermal infrared (IR) measurement flight reported very hot gas (498 to 654°C) being emitted from some of the vents on the 2019 lava extrusion.

The observation of night glow on our web cameras has continued since June 30 and is ongoing.

Tremor and volcano-seismicity has remained low and ground deformation shows an overall pattern of subsidence, with some variability.

There is still large uncertainty about the mechanisms driving the current activity. Most scenarios are consistent with a slightly increased level of unrest at Whakaari/White Island and we have therefore raised the Volcanic Alert Level to 2 (moderate to heightened unrest) and the Aviation Colour Code to Yellow. There are no obvious signs of eruptive activity.

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 at https://www.geonet.org.nz/about/volcano/val

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

Our monitoring equipment has degraded to the point we can no longer provide real-time monitoring of Whakaari/White Island.

We are relying on satellite data, inconsistent GPS data, regular gas and observation flights (weather permitting) and two webcams, one of which is significantly degraded.

We are continuing to work on options to restore our monitoring ability.

Yannik Behr

Duty Volcanologist

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