A surge of vigorous hydrothermal activity at White Island has
vulcanologists warning that even greater volcanic unrest
could be on its way.
GNS Science has stepped up monitoring of the Bay of Plenty
island after an increase in activity since late last year.
The island's volcanic alert remains at level one of five,
indicating signs of unrest, while its aviation colour code
remains at yellow, which means there are signs of elevated
GNS vulcanologist Brad Scott, who visited the island
yesterday, said the hydrothermal activity was "some of the
most vigorous I have seen at White Island for many years".
"This type of activity usually leads to stronger volcanic
activity and is a significant concern."
Future eruptions were possible with little or no warning.
Mr Scott's observations confirmed that hydrothermal activity
in the small "hot lake" had increased.
Steam and gas was "doming up" the surface of the lake,
bringing large amounts of sediment to the surface, often with
vivid white steam and gas flashing around the base.
Mr Scott said even stronger events happened every so often.
A lava dome that was first observed in late November had not
changed since it was last observed at the start of the year.
Activity at the island has been increasing since late 2012
and was now semi-continuous.
GNS Science said an eruption like one in August last year
could occur with little or no warning, despite the alert
level remaining at one.
The increased level of unrest did not mean there was a hazard
to visitors, but GNS said caution should be exercised when
visiting the island.