Volcanic activity monitored at White Island
26 January 2013 10am
Release No: 1
Scientists and Bay of Plenty Civil Defence staff are keeping a watch on White Island off the region’s coast this weekend
as seismic activity increases.
GNS scientists noticed that late this week the type of seismic activity at White Island had changed. While the level of
volcanic tremor began to decrease, ‘hybrid volcanic earthquakes’ had appeared. Hybrid earthquakes are typically
associated with movement of molten material (magma) within an active volcano.
GNS scientists took a gas flight over the volcano yesterday which showed a level of gas emitted was similar to last
month. Mud geysering is continuing in the crater lake and earthquake activity remains above background levels.
Civil Defence Emergency Management Group Controller Warwick Murray said the current episode of activity started in
August 2012 with explosions and ash emission, and in November a small lava dome appeared.
“Volcanic unrest has been increasing since about January 14. Increased hydrothermal activity in the ‘hot lake’ has been
described as some of the most vigorous seen for many years,” he said.
Mr Murray said future eruptions were possible with little or no warning, meaning an increased hazard to visitors to the
island.
“Hazards can include the health effects of volcanic gas exposure, respiratory issues, skin and eye sensitivity to acid
gases. Explosive eruptions can occur at any time with little or no warning. A high level of caution should be taken if
you are visiting White Island.”
“Scientists are not sure what could happen next. Magma could flow underground with no changes in surface activity, there
could be more dome building as in November or explosive eruptions and ash emissions, as in August last year,” he said.
“There is little risk to the mainland from this seismic activity, but we understand that people are concerned. Visitors
to White Island should ensure that they informed, and must exercise high level of caution. If you are boating near the
island throughout the long weekend, monitor marine channels for updates and exercise caution,” Mr Murray said.
Meanwhile, the Volcanic Alert Level for White Island remains at 1, indicating signs of volcanic unrest. The alert level
ranges from 0 to 5. Because of the change in activity and increased level of unrest, the Aviation Colour Code has been
lifted from yellow to orange. Aviation Colour Codes have four colours – green, yellow, orange, red as a quick reference
for planes flying in the area.
GNS Science will continue to closely monitor White Island.
ENDS