Active vents on Whakaari/White Island are continuing to throw up moderate steam and gas plumes, along with 'rare periods of ash emission”, but the Volcanic Alert Level for the island remains at Level 2.

GNS Science says a recent observation flight confirmed the active vents were continuing to emit steam and gas plumes, and periods of ash emission were also seen during clear weather over the past two weeks.

On October 19, GNS Science volcanologists observed a gas and steam plume coming from several sources behind the crater lake during a routine observation flight.

The temperature of the plume was measured at 145C, down slightly from 165C on October 5, and a gas observation flight on October 7 measured a low discharge rate of sulphur dioxide.

GNS Science duty volcanologist Craig Miller says minor, passive ash emissions were still occurring intermittently from an active vent and have been observed occasionally in satellite imagery.

'Deposits from minor ash emissions are confined to the inner crater walls. Our North Rim web camera remains obscured by a thin ash coating,” he says.

'As the weather allows, we have increased the frequency of our gas and observation flights to the island until we can service our on-island equipment and power supplies.

'We still have intermittent access to webcam images from the island, providing some level of visual monitoring between our flights.”

Miller says the Volcanic Alert Level reflects the current level of volcanic unrest or activity and is not a forecast of future activity.

While Volcanic Alert Level 2 is mostly associated with volcanic unrest hazards (including discharge of steam and hot volcanic gases, earthquakes, landslides, and hydrothermal activity), potential for eruption hazards also exists and eruptions can still occur with little or no warning.

- Matthew Martin/Stuff.