Minor amounts of volcanic ash detected in Whakaari/White Island plume

Whakaari/White Island is currently "passively" emitting a "weak-to-moderate" steam and gas plume containing minor quantities of volcanic ash, volcanologists say.

GNS Science issued a volcanic alert bulletin on Monday which upgraded the aviation colour code to orange. The volcanic alert level remained at 2, indicating "moderate to heightened volcanic unrest".

The aviation colour code was last raised to orange on December 17 when larger steam and gas plumes were visible above the volcanic island located 48km offshore of Whakatāne, before returning to yellow just before Christmas.

The aviation colour codes are only intended for use by the civil aviation community.

Duty volcanologist Craig Miller said emissions from the volcano have primarily been "weak-to-moderate" steam and gas plume emissions over the last 2-3 weeks.

"We have frequently observed very minor volcanic ash associated with the plume, and this has created hazy conditions down wind of the island."

Satellite data detected small amounts of volcanic ash in the plume, which is being blown away from the mainland by the prevailing southerly wind, he said.

"When the weather allows, a larger plume can sometimes be seen from the Bay of Plenty coast above and downwind of the island. Similarly, activity can change at short notice and produce stronger steam and gas plumes which are seen from the coast. These plumes occasionally contain volcanic ash."

Miller said without sensors, remote cameras and satellite imagery remain the only way to monitor the island.

"These levels acknowledge the current level of activity but also reflect the degree of uncertainty about the level of unrest due to the current lack of consistent, usable real-time monitoring data. The level of volcanic activity could escalate back to levels seen in 2024 and the volcano can explosively erupt with little or no warning."