Volcanic unrest continues at White Island. Following the moderate eruption that occurred on the evening of Friday 11 October the tremor level has declined, although the potential for further eruptions with little or no warning remains. The Aviation Colour Code has been lowered from Orange to Yellow but the Volcanic Alert Level remains at 2.
Volcanic tremor levels gradually decreased after the eruption on Friday and are now at levels equivalent to the middle of last week. Measurements of sulphur dioxide gas emissions from the last week show an increase in gas levels towards the end of the week with a maximum of over 1,000 tonnes/day of sulphur dioxide measured on 11 October. This is one of the highest values that we have measured since June last year.
Video compilation from the web camera on the Crater Floor shows the activity on Friday evening with a rapidly expanding ash cloud moving towards the camera. The video clip can be seen at: http://youtu.be/7YuOFddVGwc. Note times in video clips are in UTC (Co-ordinated Universal Time, 13 hours behind local time).
The accompanying photos from the crater rim camera show the effects of the eruption with one image from the day before the eruption and one image from the morning afterwards. Note how the dark grey mud coats the crater floor and crater walls. The eruption was larger than previous events over the last year, in terms of the area impacted by mud, and would have been life threatening if there had been people on the island.
A range of eruptive activity has occurred over the last 15 months, with more frequent events in the last couple of weeks. Eruptive activity can be expected with no prior warning. The larger eruptions can eject mud and rocks and may impact the crater floor area to which visitors have access.
GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project, and will provide more information as it becomes available.
Contact: Brad Scott