Volcanic activity monitored at White Island
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