GeoNet reported results from an 18 November overflight of Whakaari/White Island, noting a decrease in gas emissions and the lake level.
Gas measurements showed that sulfur dioxide emissions had decreased from 681 tons per day recorded on 2 November to 484 tons per day.
Additionally, both carbon dioxide and hydrogen sulfide decreased from 2712 to 1416 tons per day and from 38 to 19 tons per day, respectively.
The gas data suggested that molten material at depth continued to degas.
Temperatures in the main vent area were 243-264 degrees Celsius, similar to the range (202-264 degrees Celsius) measured both in September and earlier in November.
Very minor ash emissions were visible and deposits only extended around the active vents.
A new vent was observed, located S of the main vent and near the base of the 2019 landslide area.
Deposits around the new vent suggested that it formed by an energetic, steam-driven ejection of mud.
The Volcanic Alert Level remained at 2 and the Aviation Color Code remained at Yellow.