Oct 8 2002, 3:00 pm - Ruapehu Volcano

Since September 6 there have been five short-lived episodes of moderate-strong volcanic tremor at Ruapehu. This has been followed by generally higher than normal background levels since September 22. The duration of these episodes have ranged from 8 hours to more than 2 days (see plot below). Several volcanic tremor episodes have been recorded this year (see RUA-02/02), all having similar characteristics to the recent activity.

Ruapehu Crater Lake has been visited twice recently, both recording a lake temperature around 19°C. The lake temperature has been below 20°C since mid-June 2002. There have been no changes observed in the lake water chemistry or any reports of any changes at Crater Lake.

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

Peter McGinty
Duty Volcanologist

Plot of volcanic tremor amplitudes for 10 September to 8 October 2002.