Latest news & updates from White Island
Unrest at White Island volcano (New Zealand) - increasing gas emissions and small tremor
Friday Aug 03, 2012 10:05 AM | DOOR: T
Aerial view of the re-filling Crater Lake at White Island (GeoNet)
Crater Lake on March 6 2012 (GNS Science)
White Island volcano has been showing increased activity recently:
Crater Lake on July 28 2012 (Photo courtesy Volcanic Air Safaris)
The Crater Lake at the volcano started to re-fill and is showing vigorous degassing. Recent measurements confirmed that an increase in sulphur gas emissions and the presence of minor volcanic tremor.
The latest report from GeoNet on 2 Aug writes:
"During 2011 and early 2012 White Island Crater Lake slowly evaporated to expose steam vents and form two large muddy pools. However, sometime between Friday July 27 and Saturday July 28, the lake level rose quickly by about 3 m to 5 m. Vigorous flow of gas and steam through the new lake can be seen from the air. Two photos at the end of this bulletin, taken from a similar position, clearly show the change in water level.
The lake has been inaccessible for many months and we have not been able to measure changes in its temperature or chemistry. Sulphur gases measured yesterday in the steam and gas plume have increased during the last three months but CO2 gas output remains at about the same level.
Since early July there have been intermittent periods of volcanic tremor, including several hours early on Saturday July 28 and during Monday and Tuesday this week. Tremor is not uncommon at White Island but earlier this year it had been at very low levels.
A recent ground survey showed that the main crater floor is no longer subsiding and now may be slowly rising. These phenomena are typical for White Island’s activity, but are the first substantial changes to occur in the last few years.
White Island is an active volcano and there is always risk when visiting the island. Eruptions can occur at any time with little or no warning. The recent changes in activity suggest that the hydrothermal system has become unstable, and as a result the risk has increased. We advise extra caution should be taken, especially if approaching the Crater Lake and other active thermal features.
GNS Science volcanologists are monitoring the activity and further information will be released as soon as it is available.
Volcanic Alert Level remains at Level 1.
Aviation Colour Code has changed from green to yellow.
Note: The increased activity at White Island has no connection with the recent earthquakes and changes in gas flux at Tongariro volcano."
Koppelingen / Bronnen:
Koppelingen / Bronnen:
- Volcanic Alert Bulletin WI-2012/01 - Crater Lake begins to re-fill; volcanic gases and tremor increase; Alert Level remains at 1; Aviation Colour Code changed to Yellow (GeoNet)