After reporting that lake heating had stopped, GNS has issued another bulletin warning that the temperature continues to rise. Ruapehu’s Crater Lake is now at 44 °C. This is the hottest reading since the new lake formed back in the year 2000.
This increased temperature is evident with Mirova’s middle infrared radiation monitoring which has recorded a number of hot spots over the past few days. While the thermal anomaly is low (up to 2MW), readings of this nature are uncommon at Ruapehu.
In addition to the temperature warnings, vigorous steaming of the lake surface and upwelling-bubbles were observed from a scenic tourist flight. This is typical behavior when the lake is upwards of 40 °C+.
While seismic activity at Mt Ruapehu is common, the swarm of volcanic earthquakes recorded on May 3 have stopped. Such earthquakes are normally caused by magma and volcanic gases or fluids (hydrothermal) moving, causing rocks to bend at break.