Vikings Volcanic Activity Thread

[The PIT]

Indeed and whilst thats a good guide it isn't always the case. Volcanos can and do undergo subtle changes to their chemistry which can make them erupt differently from time to time. Kilaeua normally doesn't erupt explosively but it does from time to time. Likewise, Etna can erupt explosively from the summit crater but can also erupt effusively from flank rifts.

Etna is really interesting as it seems to be fed from two different sources. Indeed recent theories suggest two magma chambers one that's Hawaiian type and the other which would be more related to subduction explosive type of eruptions such as St Helens.

In recent eruptions two different types of Magma have been erupted from different zones on the Volcano. Scare stories that Etna is changing it's type of Eruptions have been played down but history past shows that it hasn't always been a nice gentle type of Volcano.

A very good source of info about Etna can be found here. http://boris.volcanoetna.com/ETNA_intro.html Sadly the Gentleman doesn't update so much these days which is sad as the information he gave was top grade.

[Guest Shetland Coastie]

REPLY FROM USGS RE YELLOWSTONE

Hi all, just heard back from a scientist at USGS re the spike in eartquake activity at Yellowstone the other day. Whilst they don't think its anything unusual it is something they are keeping an eye on. The whole caldera is undergoin inflation at the moment although it does rise and fall almost like someone breathing so it could be related to that.

[LadyPakal]

Hi Bob this Yellowstone activity thingy, I watched a docu/drama on it a year or so back. Is it/could it be the ultimate or is dramatisation.

The docu-drama was based on fact. Yellowstone is a huge volcano that has erupted previously - 6-700,000 years apart on average for the major eruptions (VEI7 & VEI8), altho' smaller ones have happened between those. The major eruptions were of different intensities but all pretty devastating. Much depends on how much magma is eruptable and we won't know that for certain until it starts erupting.

Here's a nice graphic on Wikipedia to explain the size of Yellowstone (it's last major eruption anyway) better than words can:

http://en.wikipedia.org/wiki/Image:VEIfigure_en.svg

[Guest Shetland Coastie]

The docu-drama was based on fact. Yellowstone is a huge volcano that has erupted previously - 6-700,000 years apart on average for the major eruptions (VEI7 & VEI8), altho' smaller ones have happened between those. The major eruptions were of different intensities but all pretty devastating. Much depends on how much magma is eruptable and we won't know that for certain until it starts erupting.

Here's a nice graphic on Wikipedia to explain the size of Yellowstone (it's last major eruption anyway) better than words can:

http://en.wikipedia.org/wiki/Image:VEIfigure_en.svg

Indeed LP. Yellowstone is just one of a number of large calderas dotted around the globe. They got named 'supervolcanos' because thats what the docu-drama called them, vulcanologists initially resisted using the phrase but are obviously having to because its how the wider public understand the phenomenon.

They include volcanos such as Taupo (New Zealand North Island), Toba and Tambora (Indonesia), Kiko, Aso & Asai (Japan), Long Valley(California) and Campi Flegrei (Naples - Italy).

Many of these are still active and the trouble is they only erupt infrequently, with perhaps tens or hundreds of thousands of years between eruptions but when they do, the eruptions can be colossal.

To give an example of the awesome power of such an eruption, the eruption of Toba, approximately 75,000 years ago, ejected some 2,800 cu km of material into the atmosphere and plunged the earth into a volcanic winter which eradicated 60% of the human population at the time. Like Yellowstone, Toba is still geologically active and, like Yellowstone is known as a 'resurgent caldera' i.e. its is undergoing uplift which inidcates that the magma chamber underneath is refilling. There have been large earthquakes in the vicinity of the caldera in recent times, including one epicentred at 11km below the southern shore of the lake which now fills the caldera in 1987.

Will such an event happen again? Yes very probably. In our lifetime? Considered unlikely at the moment.

Edited October 2, 2008 by Shetland Coastie

[LadyPakal]

If volcanoes are pimples on the face of the earth, I guess supervolcanoes (mega-eruptions or whatever name you prefer - personally I I like pretty nope - still swearinging scary-volcanoes) are the abcesses.

Despite the acting I did enjoy that docu-drama in a kind of depressing way (the behavour of those politicians/military in charge was all too realistic...). Usually when it is shown on the Sky HD channel (in HiDef it looks amazing BTW) the science behind Yellowstone documentary is shown afterwards - also worth a watch if anyone interested.

I find the docu-drama based on the Krakatoa eruption very good and worth a watch - it uses eye-witness documents to reconstruct the experiences of the main characters. This one: http://en.wikipedia.org/wiki/Krakatoa_-_The_Last_Days - 'Krakatoa - The Last Days'

Another good one is based on Pompeii & Vesuvius and (using some artistic license but also knowledge of who they actually were and information from an eyewitness, Pliny the Younger) reconstructs the final days of some of the people found as cavities in the ash, which they then used to made the plaster casts we see today. This one: http://en.wikipedia.org/wiki/Pompeii:_The_Last_Day - 'Pompeii: The Last Day'

Both of these pop up on Sky every so often.

Edited October 2, 2008 by LadyPakal

[Guest Shetland Coastie]

INCREASE IN ACTIVITY - REDOUBT - ALASKA

Another of Alaskas volcanos is showing possible signs of unrest. Redoubt is a large stratovolcano located 106m SW of Anchorage, on the west side of Cook Inlet.

On 16 Sept a pilot reported a strong smell of hydrogen sulfide. One week later the residents of a log cabin at Wadell Lake 15km NE of the volcano reported hearing loud noises from the volcano. In response AVO sent up an obersevation flight on 27 Sept which revealed cracks and holes in the summit glacier which had not been there before and strong fumarolic activity. As yet, there has been no significant increase in seismic activity but strong sulphur odours and increased fumarloic activity were precursors to the last eruption in 1989-90. The alert state remains at green for the time being but this could be one to watch.

[Guest Shetland Coastie]

ERUPTION! - SOPUTAN - INDONESIA

Mount Soputan on the island of Sulawesi has erupted producing a 1km high eruption plume. Currently the volcano is billowing ash and smoke and no lava flows have yet been observed. The closest villages are some 5 miles away and as yet no evacuations have been ordered.

Soputan is a relatively small stratovolcano which is also one of Indonsesias most active.

Edited October 6, 2008 by Shetland Coastie

[Guest Shetland Coastie]

UPDATE - INDONESIA - ANOTHER VOLCANO SET TO BLOW?

The eruption at Soputan has now been described as a fairly weak affair which generated a lot of smoke and ash but little else and villages in the area of the volcano have been largely unaffected. Authorities have, however, ordered the evacuation of approx 100,000 residents in the vicinity of Mount Kelud in eastern Java after warning that it could erupt at any time and placed the volcano on 'maximum alert'.

Edited October 7, 2008 by Shetland Coastie

[Guest Shetland Coastie]

UPDATE - NEVADO DEL HUILA - COLOMBIA

Nevado del Huila in Colombia continues to look as if it will burst into life at any time now. The latest report from INGEOMINAS states:

"During the past two days there has been an increase in seismic activity related to the movement of fluids to superficial levels [i.e. upper levels, near the surface] in Nevado del Huila volcano. In the last 48 hours a total of 550 events has been recorded, occurring in the form of swarms of an average four hours’ duration. From the above we have concluded that a magmatic body is being intruded into the superficial levels, causing continuous degassing with high discharges of sulphur dioxide. The foregoing is consistent with the mobile measurement carried out on 2 October, in which the flow was calculated at 10590 tonnes per day, the highest reading taken during the present year."

Watch this space for further developments.

[The PIT]

Don't know if anyone knows but do lower magnetic fields increase volcanic activity?

Are you referring to the declining strengh of the magnetic poles and the flip so north becomes south and vice versa????

[Guest Shetland Coastie]

Interesting article about the triple eruption in the Aleutians earlier this year of Okmok, Cleveland and Kasatochi.

Research carried out by Peter Cevelli of USGS is due to be published later this winter. What he seems to be suggesting is that this wasn't a coincidence and there may be some connecting factor. Be interesting to read the paper when it comes out.

Aleutians article

KASATOCHI - BEFORE & AFTER

A couple of pictures of the Kasatochi crater taken by Jeff Williams of the US Fish and Wildlife Service of the main crater at Kasatochi, before and after the eruption.

Edited October 13, 2008 by Shetland Coastie

[Crepuscular Ray]

KASATOCHI - BEFORE & AFTER

A couple of pictures of the Kasatochi crater taken by Jeff Williams of the US Fish and Wildlife Service of the main crater at Kasatochi, before and after the eruption.

Holy ****

[Guest Shetland Coastie]

UPDATE - KILAEUA - HAWAII

A wee while back we were discussing how volcanos tended to erupt in a particular manner, this being due to their chemical/gas/magma make up. I also pointed out, however, that whilst this is generally the case, volcanos can and do erupt in manner which is not in keeping with their normal eruptive behaviour and I pointed oout Kilaeua as being a case in point. Normally it erupts effusively but can, from time to time, erupt explosively.

Well the last couple of days has seen one of those times! On the morning of 12th October, there was an explosive event from the Halema'uma'u crater. This crater has been highly active for a number of months now and has been degassing elevated leves of SO2. That activity went a step further on 12th October, with what HVO has described as a 'signifcant explosive event'.

The link below will take you to the HVO website where you can download a Quick Time movie of the eruption:

HVO website

[Guest Shetland Coastie]

EARLY WARNING OF POSSIBLE ERUPTION - GALERAS - COLOMBIA

Authorities in the Colombian province of Narino are said to be on 'high alert' in anticipation of an eruption of Galeras. The volcano blew a 2,400m high column of styeam and ash into the sky today and Colombian authorities are warning of potentially a more violent eruption to come.

[Guest Shetland Coastie]

ERUPTION! - KLYUCHEVSKOI - KAMCHATKA - RUSSIAN FAR EAST

Reports suggest that a potentially major eruption could be underway at Klyuchevskoi, in Kamchatka in the Russian Far East.

Reports were initially sketchy, suggesting that the eruption was nothing more than the usual, weak, Strombolian activity for which the Kamchatkan volcanos are well known. Latest reports, however, suggest this may be something more substantial.

Russian News Agency RIA Novosti, is reporting that the volcano is spewing rocks, ash and gases, according to Alexei Ozerov of the Russian Academy of Sciences. Mr.Ozerov said: "The luminescence in the volcano's crater is becoming more intensive, which testifies to the appearance of new lava" and he warned the eruption could last for several weeks to several months.

Concern is growing for people in nearby villages as any lava flows down Klyuchevskois steep slopes could also trigger lahars as the lava melts snow and ice on the slopes of the volcano.

Edited October 19, 2008 by Shetland Coastie

[Guest Shetland Coastie]

LLAIMA WEBSITE

There is a decent website which has all manner of stuff related to the Chilean volcano Llaima. They have also just added a near-real-time seismogramme so we can keep an eye on seismic events at the volcano. Follow the linke below:

Llaima seismogramme

[Crepuscular Ray]

Here's some airborne footage of Chaiten:

http://news.bbc.co.uk/1/hi/world/americas/7703666.stm

[Guest Shetland Coastie]

There are fears that Soufriere Hills on Montserrat may be about to enter a renewed cycle of activty and one which may put the capital, Plymouth, at serious risk from pyroclastic flows: This article from Caribbean Net News:

Soufriere news

Here's some airborne footage of Chaiten:

http://news.bbc.co.uk/1/hi/world/americas/7703666.stm

Cheers CR. A particularly clear day today so some excellent views from the Chaiten webcam:

Chaiten webcam

[Crepuscular Ray]

It must be difficult to tell whether Souffriere Hills is getting more active, given that even during the "lull" in activity over the last few years there have been pyroclastic flows getting pretty near the areas not covered by the exclusion zone on a more or less daily basis. Hope they're managing to get people evacuated in time, anyway.

[The PIT]

There are fears that Soufriere Hills on Montserrat may be about to enter a renewed cycle of activty and one which may put the capital, Plymouth, at serious risk from pyroclastic flows: This article from Caribbean Net News:

Soufriere news

Cheers CR. A particularly clear day today so some excellent views from the Chaiten webcam:

Chaiten webcam

Errr Plymouth has been buried for years under pyroclastics. Somehow a few more won't make much differance bar adding to the delta where the Tar river flows into the sea.

Okay the Monserrat update fairly quiet at the moment.

Activity at the Soufriere Hills Volcano this week has been at a low level.

MVO recorded 4 rockfalls, 2 long-period rockfall, and 1 volcano-tectonic event this week. Several mudflow signals were also recorded this week during short periods of heavy rainfall.

A small pyroclastic flow in the Tar River (runout of about 1 km) was observed from MVO at 8h30 local time on October 27 2008. It generated small ash clouds that drifted over unpopulated areas to the West and Southwest towards Plymouth.

The sulphur dioxide (SO2) flux was 1143 tons per day on average for the week and 1283 over the first 6 days if we exclude a low value of 303 on 30 October which is not valid and is due to bad weather. These values are higher than last week and the weeks previous. The minimum valid measurement was 689 on October 29 and the maximum was 2540 on October 26. This value is the second highest since July 1 2008. The peak value since July 1 was recorded on September 9 2008 with 4599 tons.

The dome has been obscured by clouds and vigorous steam most of the time. The lack of helicopter support following the total destruction of the helicopter by hurricane Omar as it impacted Antigua on October 15-16, has prevented any visual and thermal airborne observations since October 17. Thanks to Gerald’s Airport General Manager and to the pilot, limited observations on October 26 were possible using a fixed-wing aircraft travelling to and from Guadeloupe. They confirm that a few small pyroclastic flows have reached about 1.5 km from the dome on the Tar River side. Headward retrogressive erosion down several V-shaped chutes continues at the base of the dome on the Tar River side and on the SE side of the dome further deepening the moat in the talus around the dome. Ongoing erosion on the western flanks of the dome talus pile on the Galways side has formed a well-incised network of gullies leading into the White River.

At this moment there is no evidence of ongoing lava extrusion but future resumption of extrusion cannot be ruled out.

Pyroclastic flows may occur without any warning, as well as mud flows, especially when there is heavy rainfall.

The Hazard Level is 3.

[Guest Shetland Coastie]

Errr Plymouth has been buried for years under pyroclastics. Somehow a few more won't make much differance bar adding to the delta where the Tar river flows into the sea.

Nice touch of sarcasm there PIT!

Sometimes I wonder why I bother its not as if I dont have enough on my plate at the mo.

[The PIT]

Nice touch of sarcasm there PIT!

Sometimes I wonder why I bother its not as if I dont have enough on my plate at the mo.

Loosen up mate bit of dry humour that's all.

Surprised you didn't know about it too be honest.

[Roo]

It must be difficult to tell whether Souffriere Hills is getting more active, given that even during the "lull" in activity over the last few years there have been pyroclastic flows getting pretty near the areas not covered by the exclusion zone on a more or less daily basis. Hope they're managing to get people evacuated in time, anyway.

Yep. It is the most amazing thing to see: was on Nevis when Montserrat went bang in 1995 and have flown over it a few times since (I was always slightly worried by the fact that the jumbos went over the top on the way to and from St Kitts/Antigua/St Lucia!) . As far as I know it's been producing stuff ever since: has always given me nice pics of smoking volcano from Nevis a few miles away.

The terrible thing is that the locals have moved right back in there, because they don't really have the option to do anything else, despite the exclusion zone.

[Guest Shetland Coastie]

Nice touch of sarcasm there PIT!

Sometimes I wonder why I bother its not as if I dont have enough on my plate at the mo.

Well I actually took my cue from the blog of well known vulcanologist Dr.Erik W Klemetti of University of California, who, being an expert in the field, I rather suspect might know what he's talking about.

Eruptions weblog

[The PIT]

Well I actually took my cue from the blog of well known vulcanologist Dr.Erik W Klemetti of University of California, who, being an expert in the field, I rather suspect might know what he's talking about.

Eruptions weblog

Hold on didn't they build a new town called Plymouth ???? I'm sure they did but can I find the links. He may have got confused by that or is just plain wrong. Best going to the horses mouth as they will know what they talking about at the following address.

http://www.mvo.ms/

They sat right next to the thing. Anyway Plymouth was abandoned in June 1997 and it doesn't look like they built a new one so my memory is wrong. Plymouth is still considered the capital despite being nearly completely buried by Pyroclastics flows.

I've added the blog to my links as it will no doubt provide updates of other eruptions.

Edited November 5, 2008 by The PIT