News and activity reports about Ruapehu volcano:
Ruapehu volcano (North Island, New Zealand) activity update
No unusual activity has been seen recently at Ruhapehu volcano. This is the latest update from GeoNet:
The Crater Lake was last hot in December 2011/January 2012 when temperatures rose to over 35 °C. Since then the lake has cooled, reaching about 16 °C in May and has fluctuated between 18 and 24 °C since then. When visited last week the temperature was 19.5 °C. The lake is a blue-green colour with weak convection near the centre.
Ruapehu volcano often has some form of seismic activity associated with it. For the last month weak volcanic tremor has been present on the records and more recently several small earthquakes have occurred under or near the volcano. The largest has been about magnitude 2.
Recently we have also completed a gas flight at Ruapehu. We can detect sulphur dioxide (SO2), carbon dioxide (CO2) and hydrogen sulphide (H2S). On 26 October the gas flux was: sulphur dioxide 63 tonnes per day and carbon dioxide flux 908 tonnes per day."
Links / Sources:
- Ruapehu Volcano update (GeoNet)
Sunday morning at 10:47 am local time, a section of Ruapehu volcano's crater walls collapsed under the pressure of the crater lake. The sudden draining of the lake caused a devastating lahar that travelled down from its altitude at 2500 m to sea level. Fortunately, the flash flood of mud drained through a river channel and no people were injured or killed. Authorities closed roads and the nation's main trunk rail track near the southern base of the mountain on New Zealand's North Island.
A similar event happened in 1953 killed when a lahar killed 151 people when it washed away a rail bridge, plunging a passenger train into the raging torrent of mud.