White Island is experiencing moderate volcanic unrest and the Volcanic Alert Level has been raised to Level 2.
GeoNet's heightened monitoring as part of the response to recent earthquake swarms has shown an increase in sulphur dioxide gas flux to historically high levels.
A gas flight today detected 1886 tons/day of sulphur dioxide, nearly three times the previous values measured in May 2019. This is the highest value recorded since 2013 and the 2nd highest since regular measurements began in 2003.
Further gas measurements will be undertaken as soon as conditions allow, GeoNet Duty Volcanologist Agnes Mazot said.
Nearby earthquake swarms are continuing although at lower levels than previously reported.
It is still unclear of the relationship of the earthquake swarms to the high sulphur dioxide observed today, Mazot said.
The change in gas flux represents a significant change in GeoNet's background monitoring parameters at Whakaari and is consistent with moderate or heightened volcanic unrest.