Ruapehu volcano (New Zealand): crater lake temperature near peak of heating cycle
The crater lake temperature has been increasing since early December 2014, rising from 15 to over 40 deg C. This is not seen as a sign that an eruption is to be expected in the near futures and the alert level remains at level 1, meaning minor unrest only.
Thu, 5 Feb 2015, 20:0020:00 PM | BY: T
The volcano's lake undergoes frequent cycles of cooling and heating. It seems that the lake is now at the peak of the current cycle. Similar temperatures were recorded in March 2011 and April 2014, before the lake cooled again.
GeoNet wrote in a special bulletin on 30 Jan:
"There are several changes in the lake chemistry. In particular we see evidence for increased amounts of volcanic gas discharging through the lake. The increase in the lake temperature and gas discharge is probably indicative of renewed heating of the hydrothermal system under the lake. Observations from recent visits and pilot reports confirm some convection is present in the lake. The lake has changed from a blue/green colour to light grey as a consequence.
Mt Ruapehu is an active volcano with a well-established monitoring regime in place and documented historic eruption record. In the past changes like those we are observing now have had two typical outcomes:
- In most cases the lake temperature reaches a maximum (40-42 °C), which is sustained for a short time (days-weeks) and then the lake starts cooling with no eruptive activity. At present the lake appears to have stopped heating.
- More rarely the lake temperature continues to increase and minor steam eruptions may start in the Crater Lake. This is very similar to the climax of many heating episodes between 1985 and 1995. If the lake temperature continued to increase larger volcanic eruptions could occur."
Links / Sources:
Links / Sources:
- Volcanic Alert Bulletin: RUA 2015/01 (GeoNet)
Wed, 3 Dec 2014, 18:48
Recent measurements by NZ scientists indicate that the volcano's crater lake is currently in a cooling trend. At 15 deg C, it has the lowest temperature recorded since April 2010. ... Read all