Whakaari/White Island: Update #20

Published: Wed Jan 22 2020 12:00 PM

Whakaari/White Island remains in an elevated state of unrest. Lava is now visible in the vents created by the eruption. Further explosive eruptions are very unlikely on any given day in the next four weeks. The Volcanic Alert Level remains at Level 2 and the Aviation Colour Code remains Yellow.

Visual observations last week and Monday (20th January) show lava has been extruded into the vents created by the December 9th eruption. In previous bulletins we proposed that magma was at a very shallow level beneath the floor of the crater, and we now have visual confirmation that this magma has risen to the surface. When magma reaches the surface, it is called lava.

Apart from minor ash emissions on December 23rd and 26th, no significantly sustained or strong eruptive activity has been observed since the December 9th eruption.

Airborne measurements of gas on Monday 20th show they are still at the high levels expected after an eruption, and the vent temperature remains very hot (> 400 C).

Considering these new observations, we have recalculated the expert judgement of eruption likelihood. It remains very unlikely (1% chance) that there will be another eruption in any 24-hour period during the next 4 weeks.

Although very unlikely, an explosive eruption from the active vent area remains possible and could occur with no precursory activity. This style of eruption could be driven by the collapse of unstable material behind the vents, or by a marked decrease in gas emissions allowing water from the reforming crater lake or geothermal system to enter the active hot gas vents.

Should any explosive activity produce an ash cloud, the likelihood of ash affecting the mainland remains low.

All our monitoring equipment on the island is operating and the camera feeds have been re-established on the GeoNet web pages.

Volcanic Alert Level remains at Level 2 Aviation Colour Code remains 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 the situation evolves.

Craig Miller, Duty Volcanologist

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