Whakaari/White Island eruption: Update #13

Published: Tue Dec 17 2019 11:45 AM

Volcanic Alert BulletinWI – 2019/25
Tue Dec 17 2019 11:45 AM; Whakaari/White Island Volcano
Volcanic Alert Level remains at 2
Aviation Colour Code remains at Orange

The volcanic tremor at Whakaari/White Island continues at a low level. No eruptions have occurred since Monday 9 December and further eruptions are unlikely in the next 24 hours. The Volcanic Alert Level remains at Level 2.

An eruption occurred at Whakaari/White Island at 2:11pm on Monday 9 December, with a devastating impact. Our thoughts remain with all those affected.

Since the eruption on Monday, December 9th, there has been no further significant eruptive activity and the level of volcanic tremor remains low.

The expert judgement made this morning calculated the likelihood of another eruption within the next 24 hours at 25 – 40%. This means another eruption is unlikely over the next 24 hours. Following this confirmed likelihood, the distances for GNS Science staff access zones have remained the same. This will be reviewed tomorrow.

From aerial observations on Saturday and Sunday (14 and 15 December) at least three open vents are seen within a 100-metre square area. One is pulsing transparent high temperature gas, which indicates magma is located not far below the surface. This open hot vent is responsible for the glow still being seen in night time camera images. There are also extensive steam and gas emissions from other active vents in the main vent area.

An explosive eruption from the main vent area can still 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 allowing groundwater to enter the vent.

Sudden steam/gas eruptions from other active vents are also possible.

As the wind remains northerly today, a sulphur-like gas smell might be noticed in the Ōpōtiki to Whakatāne area, as occurred on many occasions during the 1976 to 2000 eruptive period. People may feel this gas as a slight irritant on skin or eyes.

Should any explosive activity produce an ash cloud there is an extremely low likelihood of ash affecting the mainland in the next 24 hours. This ash would be a nuisance only, unless someone has a respiratory disorder. Check with your GP if you are concerned.

Some monitoring equipment remains partially buried under ash, but rain washing has cleared some off and helped improve solar power charging. We still receive data from the remaining equipment, which allows us to continue monitoring the volcano. Both seismic stations on the island are fully operational and are providing us with round the clock data.

We will continue to provide 24-hour estimates of eruption likelihood to support operations.

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.

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

More information will be made available within the next 24 hours, or sooner if required.

Michael Rosenberg, Duty Volcanologist

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