Volcano activity of August 5-6, 2012 - Mt. Tongariro (New Zealand) erupts for the first time since 1897!

This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Richard Wilson who specializes in Volcano seismicity and Armand Vervaeck. Please feel free to tell us about new or changed activity if we haven't written about it. -

August 5 and 6, 2012 volcano activity

New Etna volcano activity (21:07 UTC)
An increasing number of volcanic earthquakes has led to some new activity of (probably) the Nuovo Bocca crater. Check it out at this moment at both of the following webcams : Streaming Etna walk webcam (not very sensitive but with constant streaming), Lave time lapse webcam - 1 image every 2 minutes and at the INGV webcams).

Stromboli activity
What a wealth today as also Stromboli volcano shows stronger activity than during other periods.  Click here for the INGV webcam images

NEW ZEALAND VOLCANOES

Important : from now on additional news updates will be written in our special New Zealand volcanoes article. Click here to follow our reports

Update 22:09 UTC : Mount Tongariro is a popular hiking destination and searchers are checking huts this morning.
Volcanic ash is being reported as far as Napier (100km distance). Quantities of up to five cm are being reported in some places. Truck driver Brynn Rodda was driving near the mountain when it erupted and has told Radio New Zealand it was a spectacular sight. "I could see this big cloud, it looked like a fist basically, at an angle a across the sky, and at about the wrist section of the fist, there was a sudden, orange ball of flash," he said.
Incandescent material was seen by a number of people, but so far we have seen no pictures of the eruption. Some people who reported the action are talking about a "new" crater at the side of the volcano, which means that a new vent may have been opened.
The seismogram shows harmonic tremor during approx 12 minutes, which may have been the time the volcano spewed a lot of ash (see image below).

Update 21:02 UTC : As the activity at Mt Tongariro may continue for a while, we will start an in-depth article which will only carry information for the New Zealand volcanoes.

Update 20:55 UTC : Police were alerted to the eruption shortly before midnight by a member of the public who reported seeing "flame-like explosions" and a cloud of ash coming from "a new hole in the side of the mountain".
As the weather is still very bad, we have to rely on the seismographs to detect eventual new eruptions. Based on the seismogram we think the volcano is silent again with perhaps one smaller explosion 45 minutes ago.

Update : The volcano alert level has been increased to 2 and the Aviation Color code to Red.
The volcano can be seen in the webcam, however the current bad weather shows only raindrops and clouds

GNS Science and Geonet reported just a little while ago that :
An eruption occurred at Tongariro at approximately 11:50 pm (Monday, August 6). GNS Science volcanologists are monitoring the eruption and further information will be released as soon as it is available. (a lot of thanks to ER reader Kukido for informing us)
The eruption and the Harmonic Tremor can well be seen on the graph below. When you want to follow seismicity at Mt Tongariro on the live seismograph, click here

Mt Tongariro Ashfall after first eruption since 1897! - Image courtesy Geonet and GNS Science

Seismogram showing very clearly the eruption at Mt Tongariro


Small eruption at White Island Volcano

The White Island web camera has captured a small eruption on Sunday morning local time (August 5 04:55 am NZST or August 4 16:55 UTC) from the Crater Lake at White Island. During the past week there has been an increase in volcanic tremor and volcanic gas levels.
Overnight Friday July 27 to Saturday July 28 the lake level in the Crater Lake at White Island rose by about 3 m to 5 m. A volcanic earthquake was also recorded indicating an eruption may have occurred. A flow of gas and steam has been present through the lake and from vents near the lake since then. A gas flight on August 1 recorded increases of sulphur gases in the steam and volcanic gas plume.
Since early July there have been intermittent periods of volcanic tremor, becoming more continuous since July 28. A particularly stronger episode was recorded overnight August 4 - 5, and ended in a volcanic earthquake at 04:54 am NZST. Examination of the images from the Factory webcam between 04:54 am and 04:57 am on August 5 have revealed an eruption from the Crater Lake, nicely lit by the moon (see photo sequence below).
These phenomena are not unknown for White Island, but this is the first substantial confirmation that small scale eruptions are now occurring on the island and confirms the risk to visitors has increased.
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. We advise extra caution should be taken if visiting the island.
GNS Science volcanologists are monitoring the activity and further information will be released as soon as it is available.
The alert level of the volcano was raised from 1 to 2 (on a scale of 0 to 5).

Eruption at White Island on August 5 2012 - Image courtesy Geonet and GNS Science

 

White Island volcano New Zealand - RSAM and SSAM graph - image courtesy Geonet and GNS Science

Mount Tongariro volcano

The volcanic earthquakes continue beneath Mount Tongariro, but have declined in size and number. No other changes have been observed.
The sequence of volcanic earthquakes recorded at Mount Tongariro since July 13 has continued, but now there are fewer than 5 events each day and most are smaller than those in July (see graph below). Activity is currently at a lower level than in previous weeks, but may increase again at any time. The earthquake locations cluster in a zone beneath northern Tongariro (Emerald Lakes – Te Māri craters) at 2 km-7km depth.
No other changes have been observed. Initial analysis of the July gas samples confirmed that there had been a marked increase in the volcanic gas component of fumarole discharges at Tongariro. Full analysis of these samples continues.
We are planning field visits next week to retrieve data from the portable seismometers that were deployed across the mountain in late July. We also plan to repeat a survey of soil gas flux survey in the next few weeks. GNS Science volcanologists are monitoring the unrest and further information will be released as necessary.

Seismicity at Mt Tongariro - Image courtesy Geonet and GNS Science

Interesting articles
As a tourist in Iceland ? Enjoy the unique opportunity to visit a Magma Chamber
In a country that's not short of awesome, jaw-dropping sights, it's Iceland's newest tourist attraction that's grabbing the headlines this year - a trip 400 feet down inside the magma chamber of the dormant Thrihnukagigur volcano.
Astonishingly, it's not hard to experience this - the volcano is only 30kms outside Reykjavik so it's easily accessible, even to those on a mini-break or short stopover in Iceland.
However, you must tell your clients to hurry if they want to be among the 2000 or so people in the world to descend into the bowels of a once-active volcano as the company is only running tours until August 20 and there's no guarantee they will be available again next year.  Read more ...

Comments

  1. SEMEESE Roland says:

    Hello Armand,

    Zopas nieuwe uitbarsting van de Etna. Goed te zien op webcams

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