News and activity reports about Ruapehu volcano:

Ruapehu volcano (North Island, New Zealand): Volcanic Alert Level raised to Level 2; crater lake heating to over 40°C

GeoNet reported that Crater Lake (Te Wai ā-moe) temperature has been rising and is now 43ºC. During a gas flight last week, the lake was observed to be a uniform grey colour which shows it is well-mixed. The gas output through the crater lake has also increased markedly in response to this heating cycle. The amounts of carbon dioxide (CO2) and sulphur gases (SO2 and H2S) in the plume are the largest measured in the past two decades. The continued flow of gases and hydrothermal fluids though the lake shows that the underlying vent area is open.
Volcanic tremor is being produced as short-lived pulses that coincide with increased gas passing through the crater lake and its plumbing system. Modelling of energy input into the lake has shown increase during the past month from around 200 MW to around 400 MW. Since 2007 Crater Lake temperature has exceeded 40 °C a number of times, without leading to an eruption.
The combination of the increased lake temperature, volcanic tremor and gas output leads to the Alert Level change. The Volcanic Alert Level raised to Level 2 and the Aviation Colour Code is changed to Yellow.
Source: GeoNet New Zealand volcano activity update 22 December 2020