Whakaari/White Island: What the fresh ash emissions tell us

Whakaari/White Island. Photo / File

Whakaari/White Island continues to emit ash but testing shows no new magma is present, GNS Science says.

Fresh observations yesterday showed volcanic gas levels had decreased and the Volcanic Alert Level for the island remained at level 2.

Last week ash and dark plumes could be seen coming from Whakaari for the first time this year. Ash deposits were observed on some of the island's cameras, and at times, a darker plume than usual was reported from the mainland.

GNS Science said gas-measuring and observation flights yesterday still reported
small amounts of ash in the plume but observations indicated a lower level of ash emission over the past few days.

Laboratory analyses showed the ash comprised hydrothermal minerals and old
volcanic material and that no new magma was present. The ash particles were material eroded from the 2019 vent area by the flow of steam and gas.

During fine weather, plumes of gas, steam, and possibly ash would be seen rising above the island and trailing off downwind. Should any explosive activity produce a significant ash cloud, the likelihood of ash affecting the mainland remained very low, GNS Science says.

There has been no reported impact beyond Whakaari/White Island from last week's ash emission, although in onshore winds the current plume may be noticed on the mainland as weak acid rain.

During the past week, a sequence of small earthquakes and a larger-than-normal
volcanic earthquake were located close to the volcano.

Low-level volcanic tremor continues. This varied seismic activity is not unusual for Whakaari/White Island.

The Volcanic Alert Level reflected the current level of volcanic unrest or activity and was not a forecast of future activity. Volcanic Alert Level 2 indicates the primary hazards are those expected during volcanic unrest; discharge of steam and volcanic gas, earthquakes, landslides and hydrothermal activity.

While Volcano Alert Level 2 is mostly associated with environmental hazards, eruptions can still occur with little or no warning.