Mar 4 2006, 11:00 am - Ruapehu Volcano

Moderate volcanic tremor recommenced at Ruapehu on 23 February and has slowly increased in intensity, stepping up in level on 1 March (see plot below). Volcanic tremor is not unusual at Ruapehu, but little has been recorded in the last few years. This current episode is the strongest since November 2004.

The Crater Lake temperatures typically range 15 to 40° C. From August to November 2005 they were high, before falling to 24° C in January 2006. Since then the lake temperature has risen again to around 30° C, but has fallen slightly in the last few days (see plot below). When the Crater Lake was visited on 1 March the temperature was 28° C and there was no sign of the convection in the lake above the active vents.

Ruapehu Crater Lake has sometime warmed following periods of volcanic tremor, and this may follow the present period of activity. Cycles of heating and cooling are common at Ruapehu, occurring every 9 - 12 months and lasting 3 - 4 months. As the lake warms, steam plumes may be observed under favourable weather conditions above the volcano.

As there is no change in activity the Alert Level for Ruapehu remains at Alert Level 1.

Plot of volcanic tremor levels as recorded at Dome Shelter (Ruapehu).

Ruapehu Crater Lake temperatures.