article: Oct 7 2006 - Minor Eruption Now Confirmed

A visit to the summit crater lake of Ruapehu today has confirmed a small hydrothermal eruption has occurred. As suspected, the volcanic earthquake recorded on Wednesday night, which triggered the lahar warning system, did produce a small eruption. The effects of the eruption are minimal and confined to the lake basin.

Scientists from GNS Science and the Department of Conservation flew to the Crater Lake and confirmed the presence of wave action up to 4 to 5 metres above the lake surface; this was not high enough to flow over the tephra dam and form a lahar. GNS Science’s volcano surveillance coordinator Brad Scott said that, "Today’s visit has shown that the temperature of the crater lake has risen from 15 to 22.5°C. The lake water level has risen over 1 metre since the last measurement before the eruption. The temperature and water level change are as expected following this style of eruption."

Seismic activity at Ruapehu remains at typical background levels today. No further volcanic earthquakes or volcanic tremor have been recorded over the last 24 hours.

Careful monitoring of the volcano will continue.

The Alert Level remains at 1, signs of volcano unrest.