GNS reports that 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 23ºC.
The Aviation Colour Code is also changed, going from Yellow to Green.
A gas flight was completed yesterday and recorded the gas output at levels typical of background for Mt Ruapehu. The level of volcanic tremor which has been elevated to moderate levels has declined and shows now similar levels to what it was in the second
half of 2015. The lake temperature measured by the outlet data logger is now 23 ºC.
After reaching a high of 46 ºC on May 11 the lake started to cool to the current value of 23 ºC. Data available at present indicates the period of elevated volcanic unrest at Mt Ruapehu is over.
The volcanic alert level for Mt Ruapehu is now lowered Volcanic Alert Level 1 (minor volcanic unrest). The Aviation Colour Code is also changed from Yellow to Green.
GNS Science volcanologists continue to closely monitor Ruapehu through the GeoNet project.