The increase in sulphur dioxide emissions from Whakaari/White Island has continued, says GNS duty volcanologist Paul Jarvis.

An update on the minor eruptive activity was released by the agency this morning. The Volcanic Alert Level remains at Level 3, and the Aviation Colour Code remains at Orange.

“An observation flight on Wednesday 21 Aug 2024 and ongoing satellite imagery confirms that minor eruptive activity Whakaari/White Island continues from the new vent that became active in early August,” says Paul.

Paul says satellite data further suggests that SO2 levels remain high.

“The amount of volcanic ash in the plume has not changed much over the last week. There remains a very low likelihood of ash falling on the ground on the mainland.”

Paul says the observation flight confirmed activity was confined to just one active vent on the island “The vent was emitting a plume of fine volcanic ash that rose to about 600-900 m before being dispersed downwind. Ashfall was restricted to within 1 km of the island.”

He says thermal infrared imagery captured during the flight showed a vent temperature of about 590 degrees Celsius.

“In addition to our observation flight, our webcams at Whakatāne and Te Kaha have observed that the plume can reach an altitude of about 2 km under calm conditions,” says Paul.

“NZ MetService are also able to use satellite imagery to track the volcanic ash plume for tens of kilometres downwind of the volcano when skies are clear.

“Satellite data obtained on 21 and 22 August confirm that the increase in SO2 emissions from Whakaari that we previously reported has continued.”

Ash cloud from Whakaari/White Island on Wednesday 21 August 21. Photo: B. Scott.

Paul says a further satellite-based monitoring technique which can detect deformation of the ground surface shows no major changes in the active vent area.

“Our observations and data confirm there has been little change in the eruptive activity over the last seven to 10 days. Small amounts of volcanic ash continue to be emitted into the plume and SO2 emissions remain elevated.”

Paul says although looking spectacular, the ongoing eruption is small and the concentration of volcanic ash in the plume is very low and sometimes difficult to detect.

“Overall, the activity is consistent with magma (molten rock) being close to the surface and driving the activity.

“As wind directions change, the plume may at times be blown towards the Bay of Plenty coast and pass overhead as happened on Thursday and Friday last week [August 22 and 23 August].

“However, at the current level of ash emission, there is a very low likelihood of some of that ash falling to the ground (ashfall). The level of volcanic activity would have to escalate significantly for this likelihood to increase.”

GNS Science’s Volcano Monitoring Group and National Geohazards Monitoring Centre will continue to closely monitor volcanic activity at Whakaari with remote cameras, satellite imagery, and regular monitoring flights.

“We will provide updates when information becomes available,” says Paul

Further information about the Volcanic Alert Levels and what they mean can be found here.

For information about the impacts of the steam and gas plume or volcanic ash should it reach the coast, follow the advice from:

• Bay of Plenty Emergency Management
• NEMA: What to do during volcanic activity
• Toi Te Ora Public Health: Volcanic Activity