Clear and cold conditions have contributed to impressive plumes from Whakaari/White Island recently despite no clear eruptive activity, GNS Science says.
In a statement today, the research institute said it had observed a more vigorous steam and gas plume rising from volcanic island since July 3.
The volcanic alert level remains at level 2 and the aviation colour code remains yellow.
Social media has been flooded with people posting photos of the plumes taken from the coast.
Duty volcanologist Michael Rosenberg said calm and cool weather conditions offshore from Bay of Plenty recently had allowed for very clear views of the activity for many from the coast.
“No clear eruptive activity has been observed at Whakaari/White Island since Saturday, May 25,” he said.
“When views are clear from our web camera in Whakatāne, we often observe low-level and weak steam and gas emissions from the island. These appear to have increased slightly since Wednesday last week and the plume appears hazier as the gas and vapour content increases.
“Cold air can help condense water vapour and make the plume look more obvious. Sunlight at different times of the day can also make the plume look different colours from white to grey to pale orange-brown,” Rosenberg said.
“Satellite sensors have not detected sulphur dioxide gas or volcanic ash, and we have not seen any volcanic ash emissions in web camera images.”
Rosenberg said changes in the plume had been seen many times in the past and represented normal processes in the volcano, like those happening since May, as the lake and main crater area slowly dried out.
GNS Science said that although the volcanic alert level remained at level 2, eruptions could occur with little or no warning.
Niwa Weather posted a satellite image showing a visible plume coming off Whakaari on social media last week.
The owners of Whakaari-White Island want to grant GNS access to the volcano and would do so immediately if legally able to, their lawyer says.
James Cairney, barrister for Whakaari-White Island owners Andrew, James and Peter Buttle, responded to statements from Whakatāne Mayor Dr Victor Luca that not allowing monitoring of the volcano is putting the public at risk.
Luca told Local Democracy Reporting last week the Buttle brothers’ Whakaari Management was the owner of “a potential time bomb” that would affect everybody if a major eruption occurred.
The brothers are shareholders in Whakaari Management, which is appealing a guilty verdict on health and safety offences for allowing people on the island.
This followed the December 2019 eruption that resulted in the deaths of 22 people.
Cairney said the mayors had not raised this concern with the Buttles but the family had had discussions with GNS to try and resolve the issue.
“[The Buttles] are not allowing anyone to access the island, due to the risks to people on the island.
“The family’s company [that granted access] was found guilty at trial for allowing access to the island. The matter is under appeal.
“Whereas the family think that GNS should be able to go to Whakaari and manage the risks to their staff themselves, following the court decision, the family are not sure they are allowed to let GNS do that.
“They consider that, until the legal matter is sorted, they must assume to have responsibility for the safety of people who they permit to go to the island, and thus cannot allow people to go to the island.
“The family would love to grant GNS access and would do so immediately if they were legally able to allow them to go.”
- Additional reporting from Diane McCarthy at Local Democracy Reporting
The couple spend five months a year in America running their business.