Science Alert Bulletin RUA-2007/03 - Ruapehu Volcano

Published: Wed Sep 26 2007 3:30 PM

Volcanic Alert BulletinRUA-2007/03
Ruapehu Volcano
Volcanic Alert Level remains at 2

26 September 2007, 3:30 pm - Eruption from Ruapehu: Science Alert Level remains at Level 2

An eruption of Ruapehu occurred at about 8:20 pm last night. Small lahars were produced into the top of the Whakapapa skifield and down the Whangaehu valley. Activity lasted about 10 minutes and, since this time, only a low level of seismic activity has been measured at GeoNet sensors on the mountain.

Observations from an early morning flight today showed that the summit area is covered by ashfall and mud, with most of this being directed to the north, reaching to about 2km from the Crater Lake. The summit area was also peppered by craters caused by large blocks (over 1m across) ejected from the bottom of the lake. The lake is now below overflow (about 2 - 3 metres).

Our current understanding of the activity is that this is most likely an isolated “blue sky” eruption similar to events in 1969, 1975, 1988 and 2006. However, there is still a possibility that there may be further eruptions over the next few days and weeks.

GNS scientists will continue to monitor the activity closely over the forthcoming days, and keep the public advised of any further developments.

Gill Jolly
Volcanology Section Manager