Volcano Alert Bulletins (VABs) are New Zealand's official source of volcano status information including the current Volcanic Alert Level (VAL).
They are issued on an as needed basis summarising the volcano status and recent events.
They can indicate if activity is increasing, decreasing, or in a steady state. They may contain forecasts, highlight developing, or expected problems.
If you’d like to be notified as soon as we issue a new bulletin, our social media channels and the GeoNet app will keep you up-to-date.
Te Wai ā-moe (Crater Lake) temperature at Mt Ruapehu is rising along with an increase in volcanic tremor. This is consistent with minor volcanic unrest behaviour. The Volcanic Alert Level remains at 1.
The episode of volcanic earthquakes beneath Mt Ruapehu has ended, and observations and models indicate the heating phase of the Crater Lake (Te Wai ā-moe) has likewise ended.
An episode of volcanic earthquakes is occurring beneath Mt Ruapehu since 15 March. This is a common observation during a heating phase of the crater lake (Te Wai ā-moe).
Carbon Dioxide (CO2) gas emission rates at Mt Ruapehu have returned to a more normal level. The period of slightly higher volcanic unrest appears to have ended. The Volcanic Alert Level remains at 1.
Measured changes in Crater Lake water and gas composition confirm the slightly elevated level of activity at Mt Ruapehu. The lake temperature (37ºC) and the level of seismic tremor remain unchanged. The Volcanic Alert Level remains at 1.
An increase in volcanic gas emissions and sustained high lake temperature suggest a slightly higher level of activity at Mt Ruapehu. The Volcanic Alert Level remains at 1.
Since early September, Mt Ruapehu’s Crater Lake had been heating at a rate of around 1°C per day, reaching a maximum of 40ºC on October 4. The lake temperature has cooled slightly since then and is now hovering around 37°C. After October 18, the level of volcanic tremor under Mt Ruapehu increased in strength. Volcanic tremor is always present at Mt Ruapehu, however the level can vary.
This morning, steam plumes have been visible above Mt Ruapehu’s Crater Lake. The lake temperature is now 37 ºC as part of a heating episode that began around 2-3 September 2016. No seismic or acoustic activity has been recorded this morning, indicating the steam plume was not generated by activity in the lake. The Volcanic Alert Level for Mt Ruapehu remains at Level 1 (minor volcanic unrest) and the Aviation Colour Code also remains unchanged at Green.
Last week a Crater Lake sampling and gas flight were completed by GeoNet staff at Mt Ruapehu. Observations and data from these activities confirm the Crater Lake is still cooling, but at a slower rate and there is volcanic gas passing through the lake.
The moderate to high level of volcanic unrest at Mt Ruapehu is no longer present and the Volcanic Alert Level is now lowered to Volcanic Alert Level 1 (minor volcanic unrest). The gas emissions decreased and the level of volcanic tremor has also declined. The temperature of the summit Crater Lake has declined from 46 ºC (11 May) and is now at 23 ºC. The Aviation Colour Code is also changed, going from Yellow to Green.