Minor activity re-established at White Island volcano, New Zealand

GNS Science volcanologist Brad Scott reported today that minor activity has become re-established over the last 24 hours. The Volcano Alert Level remains at Level 1 and Aviation Color Code has been raised to Yellow.

Following an increase in volcanic tremor levels overnight and images of activity on the volcano cameras, a response visit was made this afternoon. Scott reported they saw two styles of activity in the active vent. Audible jets of gas were being shot through the small lake and broader expanding ‘bubbles’ of dark lake sediments and debris were being ejected 20-30 m vertically. The activity is very similar to earlier this year.

The potential for larger, more explosive eruptions that might impact on visitors to the island is always present. Any larger eruptions may occur with no warning to any visitors to the island.

The ultimate outcome of the current activity at White Island remains unclear and GNS Science continues to closely monitor White Island through the GeoNet project. There is no reason to believe this change is related to the Cook Strait earthquakes.

Unrest at White Island began in July 2012, leading to explosive eruptions and ash emissions in August. A small lava extrusion occurred in November, followed by phreatic, steam driven activity in December which continued through January and February 2013. Very minor ash emissions have been interspersed throughout this eruption sequence as conditions within the craters have changed.

On July 11, 2013 GNS reported that small tremor bursts are occurring like clockwork, approximately every 70 seconds, creating a unique pattern on our earthquake drum, with hundreds of these small bursts recorded every day.

• White Island drums and webcams are here.

White Island, showing the white clouds of highly acidic gases. Image courtesy of GNS Science – GeoNet

• Aviation Color Codes are based on four colours and are intended for quick reference only in the international civil aviation community. 
• The Volcanic Alert Level ranges from 0 to 5 and defines the current status at a volcano. Level 1 indicates signs of volcanic unrest.

Source and featured image: GeoNet