New Zealand Local Weather Forum
General Category => General Discussion => Topic started by: JennyLeez on August 20, 2013, 05:08:04 PM
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A small eruption occurred at White Island at 10:23 on Tuesday 20 August 2013 (NZ local time) and continued for about 10 minutes. The eruption column was visible from the Bay of Plenty coast with a plume rising to about 4 km above sea level before slowly dispersing.
The activity at White Island has now returned to that before this morning's eruption.
The eruption originated in the active crater area that has been experiencing very small mud eruptions in recent weeks. The eruption threw mud and rocks a short distance from the source, and produced large volumes of white steam. Weather radar observations show that a small proportion of volcanic ash was carried with the steam.
White Island has been experiencing low level activity since August 2012 so an eruption like that this morning was not completely unexpected. Volcanologists observed a short period of strong volcanic tremor yesterday morning, but is is not clear if this was related to this morning's eruption.
The hazards posed by an eruption like that this morning are restricted to anyone on White Island or possibly anchored nearby in a boat. Anyone living in the Bay of Plenty is not at risk.
Duty Volcanologist Nico Fournier said “It is too soon for any kind of prediction of activity in the next few days. Given the low level of activity over the last year we are watching carefully and would not be surprised if there were further eruptions in the next few days”.
http://www.geonet.org.nz/volcano/info/whiteisland (http://www.geonet.org.nz/volcano/info/whiteisland)
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Update:
Following the lower level of activity at White Island since yesterday’s eruption, GNS Science has lowered the Volcanic Alert Level to 1 and the Aviation Colour Code to Yellow.
The level of volcanic activity at White Island has decreased substantially since yesterday’s eruption. Steam and gas continue to be emitted from the active crater, in a similar fashion to that prior to the eruption. The GeoNet monitoring network continues to record seismic activity, as expected from a volcano that has been experiencing unrest for over a year.
GNS volcanologist Agnes Mazot said: “We are planning to fly around the White island and take airborne measurements of the amount of gas being emitted from the volcano. The weather is not cooperating at the moment and will are aiming at a flight possibly on Friday”.
Although the activity at White Island is currently at a low level, eruptions similar to those experienced over the past year are possible with no prior warning. These include mud geysering, more energetic eruptions similar to yesterday’s event, or ash from the active vents. Such eruptions can eject mud and rocks and may impact the crater floor area where visitors to the island may be.
There is presently no clear indication that yesterday’s eruption is leading to a large eruption, but eruptions similar to those in the last year cannot be excluded over the days or weeks to come.