Signs of increased activity at White Island are not linked to the Cook Strait earthquakes, says GNS Science.

The organisation has raised the aviation code from green to yellow following a visit to the volcano yesterday afternoon.

Increased activity at White Island.

This means the volcano is experiencing signs of unrest above known background levels, says the organisations website.

Volcanologist Brad Scott says scientist visited the volcano following an increase in volcanic tremor levels on Thursday.

'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.”

He says the potential for larger, more explosive eruptions 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.”

Brad says 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.

Since then, Brad says very minor ash emissions have been interspersed throughout this eruption sequence as conditions within the craters have changed.
The Volcanic Alert Level ranges from zero to five and defines the current status at a volcano.

Level one indicates signs of volcanic unrest.
Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community.