For all things relating to tectonic plate collisions. Earthquakes, volcanic eruptions and tsunamis... the Pacific ring of fire and world-wide. Please create new threads for stronger earthquakes when they happen above magnitude 5.0.
I thought it is worth while giving White Isaland a topic of its own so we are not hijaking the Tongariro topic.
Geonet
Aug 2 2012, 3:00 pm - White Island Volcano
Crater Lake at White Island has recently started to re-fill and gases are now vigorously streaming through it. Airborne gas measurements made yesterday show that the discharge of some sulphur gases has increased. During the past few weeks there has also been some minor volcanic tremor.
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.
The increased activity at White Island has no connection with the recent earthquakes and changes in gas flux at Tongariro volcano.
Volcanic Alert Level remains at Level 1
Aviation Colour Code has changed from green to yellow
Geonet
Aug 5 2012 - White Island update
With the weather clearing up the steam plume has been clearly visible today.
After the rapid rise in White Island's crater lake, a pulse of volcanic tremor and slightly higher gas levels in the plume, there have been few obvious changes. During the week the activity has been greater than it has been during the last couple of years, but seems to have been relatively stable. Although the volcanic tremor increased substantially during Saturday it has returned to levels similar to those during the early part of last week.
The white steam plume visible on GeoNet's White Island web cameras can sometimes also be seen from areas of the Bay of Plenty coast.
GNS volcanologists plan to visit White Island early next week to collect water and gas samples and make a ground level survey of the crater floor. These measurements will help understand what changes are taking place beneath the volcano and whether these might lead to increased surface activity.
Yes, Geonet have raised the volcanic alert level to level 2 but are having some communication issues and trouble updating the website according to them on twitter and facebook.
Rosenberg said scientists believed there was something changing in the magma underneath the volcano.
"It's either that a pulse of gas is being released from that magma and that's providing a bit of extra pressure to push everything else towards the surface, or possibly it's a small amount of magma pushing closer to the surface. We are unsure at this stage."
I see the Geonet has also changed the aviation colour code to Orange too, meaning:
Geonet wrote:Volcano is exhibiting heightened unrest with increased likelihood of eruption. Or: Volcanic eruption is underway with no or minor ash emission
going by the ammount of material on the crater rim carmera today compared to yesterday im thinking there was more eruptive activity over night or this morning. the ongoing tremmor looks to have eased back today.
Yews Geonet confirm they suspect a another burp at White Island overnight, pcorrelating with seismicity at the time
Would be fair to change this to eruptive ativity at White Island in line the the Tongariro thread!
yea im also finding depending on what way you get to info about the two volcanoes at the moment depends on what alert levels they read. You can get alert 1 and yellow by getting to both white island and tongariro through a series of links. By going through another series of links you get them both on level 2 and orange. Not very informative with conflicting warnings on the same site.
Yes it probably is worth having the thread title changed.
Around 11:30 pm on August 7 volcanic tremor at White Island sharply decreased to levels seen prior to the current episode of unrest in late July. A few hours after this drop in tremor, the colour of the plume changed from white to light brown, indicating more ash is now in the plume. Visual observations in recent days show that a small cone is being built in the lake, around the main area of degassing.
This is the first time ash has been produced from White Island since 2000 and may represent the start of a new phase of activity at White Island.
Visitors to White Island are now at the highest level of risk since the end of the 2000 eruptions. Additional hazards to visitors to the island now include the health effects of ash and acid gas exposure, including respiratory issues, skin and eye sensitivity to acid gases. These hazards increase significantly towards the Crater Lake rim. Eruptions can occur at any time with little or no warning. We advise a high level of caution should be taken, if visiting the island.
The ashfall prediction plot for 6:00 pm today indicates where volcanic ash may be deposited if ash continues to be produced from the volcano.
GNS volcanologists plan to visit the island this week to assess the situation and undertake further sampling and measurements.
Volcanic Alert Level remains at 2
Aviation Colour Code remains at Orange
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Daniel Phillips on Facebook posted an album of new White Island photos when he flew around the island on Tuesday. Some photos show a new cone forming in the middle of the lake.
kiwisk8er wrote:Daniel Phillips on Facebook posted an album of new White Island photos when he flew around the island on Tuesday. Some photos show a new cone forming in the middle of the lake.
Campbell Live had a good story on White Island on. They catched a flight with GNS, the volcano had some ash eruption but mostly steam. Will post the link when the video is up.
Some reckon on radio live its causing lightning,others say its moving sugesting the lightning is weather related but in a SW flow there be no lightning?
