Eruptive Activity at White Island

[tgsnoopy]

And the grumblings are back again. Where will they lead?

[David]

And the grumblings are back again. Where will they lead?

I think the tremor dropping is related the hydrothermal system drying out. Although I don't know why it drops then suddenly comes back strong.

I've given up guessing

[Razor]

Yes its a pretty volatile situation it would seem. Definitely some ash eruptions on Saturday, whats next who really knows.

[tgsnoopy]

Current drum image

Just adding it for reference as it's on the previous page, not this. Saves members going to see what's happening. Looked pretty boring today whilst I was down Whakatane way and was looking.

Saved version for future reference:

wiz-seismic-drum.JPG

[Razor]

The RSAM chart is hitting really high levels this evening, could be something brewing alright. New alert out from Geonet too, they say the most active in many years

[David]

The RSAM chart is hitting really high levels this evening, could be something brewing alright. New alert out from Geonet too, they say the most active in many years

And just like that... it looks like the tremor has dropped to almost nothing again!

[jamie]

Has it just stopped recording? The reason I ask is because the RSAM is still showing a strong tremor.

[Razor]

Yes looks to me like its got a 'fault'? Back now still showing strong tremor

[jamie]

seems as though it has run out of puff...... for now.

[tgsnoopy]

GNS seems to think it's settled back down again too...

4 March 2013, 4:00pm - Update; Volcanic Alert lowered to Level 1, Aviation Colour Code changed to Yellow.

Ash emission at White Island has ceased for the moment and the Volcano Alert Level is reduced to 1 with the Aviation Colour Code changing to Yellow.

Observations in the last week have shown that a small ash cone has been built in the “hot lake” crater, which is the current focus of activity. The ash cone is surrounded by a small moat of water.

It is likely that in the short term, activity will alternate between dry and wet eruptions. When drier conditions prevail, like last week, some volcanic ash may be produced. If there is an increase in water near the vent then phreatic (steam-driven) eruptions may occur. The crater containing the lava dome remains unchanged.

Seismic tremor levels are currently low, which is thought to partly reflect the lack of water involvement in the current activity. A gas flight on 26 February measured around 600 tonnes per day of SO2 (sulphur dioxide), and 1,950 tonnes per day of CO2 (carbon dioxide), similar to other measurements made since the start of 2013.

White Island remains in a heightened state of unrest and the long term outcome of the unrest remains unclear. It could lead to explosive eruptions and larger ash emissions, like in August 2012, or decline to background activity. In the short term it is expected that activity will be variable, largely reflecting the influence of water on the style of activity.

Background

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. Minor ash emissions have been interspersed throughout this eruption sequence as conditions within the craters have changed.

The Volcanic Alert Level ranges from 0 to 5 and defines the current status at a volcano. Level 1 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.

Craig Miller
Duty Volcanologist

[Razor]

Hmmm I'm not sure Craig is saying it has settled down, rather that it is somewhat undecided

[tgsnoopy]

Yes, for the moment.

I watch the webcams & seismograph with interest to see what will be it's next move.

[tgsnoopy]

And the tremor is picking back up again.

[tgsnoopy]

It didn't last long now did it. Oh well, might try to remember to take a camera with me down Opotiki way tomorrow, just in case.

[jamie]

Throw a bit of moisture into the crater and she goes bazurk! Has really ramped up quickly since yesterday afternoon.

[Razor]

Far out check out the volcanic earthquakes - over 30 of them in the last half hour. Something happening all right

[jamie]

i bet it eases off once it dries back out.

[tgsnoopy]

Current drum image

Got rather active overnight!

Saved Image:

wiz-seismic-drum.GIF

[Razor]

Yep fair fizzing under there somewhere today

[jamie]

still no word from geonet

[Razor]

I think there may just have been an eruption....and the tremor ceased just after

[tgsnoopy]

Darn, why couldn't that have happened during the day whilst I was down there. I started at Omaramutu, went down to Omaio, back to Omaramutu then back down to Torere.

[bmo]

Looks like it might have had a little burp

[David]

Hmmm, I'm not convinced it erupted based on the webcam shots... looks like steam/gas plume to me.

[jamie]

Hmmm, I'm not convinced it erupted based on the webcam shots... looks like steam/gas plume to me.

I strongly disagree with you David... check out the crater web cam. its filthy! I wasnt too sure myself last night but looking this morning im a yes.