A recent monitoring flight observed evidence of “intermittent explosive activity” on the crater floor at Whakaari/White Island as the volcano continues to emit gas and steam plumes, volcanologists say.
A Volcanic Alert Level 2 remained in place, indicating moderate to heightened volcanic unrest, and the Aviation Colour Code remained at Orange.
GNS Science duty volcanologist Brad Scott said webcams had recorded steam and gas plumes with a “minor but variable” presence of volcanic ash.
Recent gas and observation flights confirmed what had been seen from the coast, Scott said, with a flight on Friday recording a slight enlargement of the active vent area.
“We also observed impact craters, suggesting that some occasional, more explosive activity has recently occurred, ejecting ballistic blocks up to about 600m from the active vent, on the crater floor.”
Temperature measurements of the active vent also increased, rising from 220C in January to 360C on March 22.
Sulphur dioxide emissions continue to be detected by satellite, and Scott said during northerly wind conditions the minor ash load in the steam and gas plume may be noticed by residents on the coast as sulphur odours.
“Steam, gas, and volcanic ash emissions remain variable as they have been for the past few months.”
The lack of consistent, usable real-time monitoring data means volcanic activity could escalate with little to no warning, he added.
“Further sudden, more explosive events could therefore affect the crater floor area and immediate vicinity of the island.”
