White Island unrest continues

Activity from White Island in 2013. Scientists are noticing continued activity there at the moment. PHOTO/FILE

Routine monitoring of White Island indicates minor volcanic unrest continues.

Over the last couple of weeks GNS scientists have observed a fall of 2m in the water level of the crater lake. However they have not noted any changes in other monitored parameters like the amount of volcanic gas being emitted, fumarole temperatures and the presence of volcanic tremor or earthquakes.

During a visit last week by GNS volcanologist Brad Scott he was able to confirm the lake level had dropped 2m in the last 2 weeks. The lake was now about the same level as it was in 2014. The drop in water level of the crater lake has revealed several islands or crater outlines and the lake temperature has increased 2C, from 56C to 58C, since February.

There had been a small decrease in the temperature of the hottest fumarole (169C to 161C) since February. The SO2 gas output has ranged between 90 and 480 tonnes per day (1.0 to 5.5 kg per second) of gas during the last 5 weeks. These are typical values for White Island.

The level of volcanic tremor continues to vary, but remains below those observed in 2012 when unrest was stronger and small eruptions occurred.

The Volcanic Alert Level remains at level 1 (minor volcanic unrest). The changes being seen were consistent with minor volcanic unrest. Typical volcanic unrest hazards like hot ground and gas remain. A range of activity can occur under these conditions with little or no useful warning.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.