Tremor levels at White Island have declined since an eruption on Friday but the risk of further eruption remains.

GNS Science said 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.

Volcanologist Gill Jolly said Friday's 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.


There has been a range of eruptive activity at the island over the past 15 months, with more frequent events in the last couple of weeks.

Dr Jolly said eruptive activity can be expected with no prior warning.

The larger eruptions can eject mud and rocks and may impact the crater floor area where visitors to the island are located.

Measurements of sulphur dioxide gas emissions from the last week showed an increase in gas levels towards the end of the week and was one of the highest values measured by GNS since June last year.