A minor eruption at Whakaari/White Island is continuing as volcanologists report the total gas output from the volcano “remains higher than normal”.
The alert level at the volcano was raised to three early last month as it continues to go through an extended active period. GNS Science issued a new update on the eruption this afternoon.
Although a visible plume sometimes reached a kilometre above Whakaari, the ash from it has been falling only within 1-3km of the island.
The “likelihood of ash fallout on the mainland remains very low”, GNS Science said, and the volcanic alert level remains at level three (minor eruption), while the aviation colour code remains at orange.
GNS Science said overall gas output from the volcano “remains higher than normal”.
According to the agency, gas flux data from a September 5 flight point to some of the “highest measured sulphur dioxide emissions in the last 20 years”. Data from yesterday then showed a decrease which is “consistent with other observations of the plume.”
Nearby flights were disrupted by the minor eruption last month.
Duty volcanologist Michael Rosenberg said yesterday’s flight showed the “vent area has enlarged slightly and the emissions are now more variable”.
“GeoNet camera images showed a higher and darker plume, suggesting that the amount of volcanic ash had increased substantially, while this morning the images indicate a lot less ash is present,” he said in an update.
“The plumes have been rising to a few hundred metres above the volcano before being dispersed tens of kilometres downwind by local winds.”
MetService has tracked the plume for tens to over 100km downwind of the volcano.
“Our observations and data indicate small changes in the eruptive activity have occurred over the last 7-10 days,” Rosenberg said.
“Our observations and the high emissions of hot gas, indicate magma remains likely to be close to the surface and releasing its gases with some minor amount of volcanic ash.”
The volcanologist said the level of activity at Whakaari would have to “escalate significantly” for the likelihood of ash falling to the ground in coastal areas.
“People living in the coastal regions might notice a slight sulphur smell from the volcano plume when winds blow the plume inland,” he said.
“Currently, the small amount of ash carried in the plume and its very fine grain size, means there is a very low likelihood of ash falling to the ground in coastal areas of the North Island.”
