Published: Fri Dec 22 2017 4:00 PM
As 2017 comes to an end, the GeoNet's volcano monitoring team recently made a series of visits to White Island, this being the last detailed assessment of New Zealand's most active volcano before the summer break.
Changes in volcanic activity occur at different timescales. For rapidly changing dataset, GeoNet relies mostly on remote instrumentation and our 24/7 operation duty team. Some changes however, occur more slowly and can be monitored by making field visits to the volcano. Some of the monitoring techniques we use at White Island only record long-term, gradual changes. We make those measurements when we visit the volcano, typically four times a year. These slowly changing data include ground uplift and subsidence, the chemistry of fumaroles and hot springs, the status of the Crater Lake (when present), the gas leaking through the soils, and the magnetic intensity of the rocks beneath the volcano.
Other monitoring techniques, earthquake activity, the rate of volcanic gases coming from the volcano, and some kinds of ground deformation, can show very rapid changes, so we have to measure these more frequently, or even remotely and automatically.
Our visits to White Island over the last 10 days showed that, while visitors to the volcano can see fumaroles up to 149 degree C, a small pool on the crater floor and hear gas roaring from the active vents, the volcano remains relatively quiet and overall at a low level of unrest (Alert Level 1).
The duty volcanologists will continue to monitor the volcano for possible renewed activity over the Xmas-New Year break. The Volcanic Alert Level remains at Level 1.