Gas and steam flux data from the September 5th flight indicates some of the highest recorded sulfur dioxide (SO2) emissions in the past 20 years.
However, data from the 11th shows a decrease, aligning with other observations of the plume. Despite these fluctuations, the overall gas output from the volcano remains above normal levels.
Recent observations from yesterday’s flight reveal that the vent area has slightly expanded, with emissions now showing greater variability. On Wednesday the 11th, GeoNet camera images captured a taller and darker plume, indicating a significant increase in ash emissions.
This morning, however, the images show much less ash present. The plumes have been rising several hundred metres above the volcano, carried tens of kilometres downwind by local winds. At times, the plume reached up to a kilometre above the island, but ash fallout has been limited to within 1–3 km of the island, and the risk of ash reaching the mainland remains very low.
With clear views, GeoNet cameras at Whakatāne and Te Kaha have showed a continuous volcanic plume and using satellite imagery, NZ MetService have tracked the plume for tens to over 100 kilometres downwind of the volcano. Under some conditions the plume has passed over the land.
The GeoNet continue: „Our observations and data indicate small changes in the eruptive activity have occurred over the last 7-10 days. Strong emission of volcanic gases with small amounts of ash continues and is variable through time. The vent area changed shape sometime be-tween the 5th and 11th of this month. Our observations and the high emissions of hot gas, indicate magma (molten rock) remains likely to be close to the surface and releasing its gases with some minor amount of volcanic ash. Although the vent area has changed slightly and the amount of gas and ash varies through time, the ongoing eruption broadly appears to be of small size and quite steady. The size of the ash grains sampled on September 5th and 11th flights was measured at between 0.005 mm and 0.05 mm (5 to 50 thousandths of a millimetre) in size.“
The alert level for the volcano remains at Level 3.
Source: Geonet New Zealand volcano activity update 12 September 2024