General Weather - all topics not current severe weather.

[Jimmy Deguara]

In this section, I would not mind people commenting and adding pictures as well as videos as to the famous volcanic eruptions. The crisp clouds and also the incredible structures associated with these massive plumes are certainly spectacular. Start with

Mt Pinatubo - Pictures and sources quoted


http://www.calstatela.edu/faculty/acolvil/volcanos.html



http://platetectonics.pwnet.org/story_tectonics/tectonics_and_people.htm


http://park.org/Philippines/pinatubo/index.html


http://vulcan.wr.usgs.gov/Volcanoes/Philippines/Pinatubo/images.html

Wow! These websites have really provided some awesome imagery of this eruption.

Regards,

Jimmy Deguara

[Mike]

That's just incredible!  Just awe inspiring stuff.  Here's my addition to this with photo of Mayon volcano 29 Feb 2000 with the tower reaching 12km up.  The second photo is of Mt Etna the others are of an eruption at Anathan Island in the Pacific.  Respective credits listed.

Mike

http://news.bbc.co.uk/1/hi/world/asia-pacific/660943.stm

http://www.volcanodiscovery.com/volcano-tours/etna/photos/se-crater_nov_2006.html

http://news-info.wustl.edu/news/page/normal/235.html

[Jimmy Deguara]

Mike,

See if you can uncover the spectacular cloud that was formed in I think a South American volcano - that was one of the most impressive volcanic cloud plumes I have ever observed - saw it on a documentary.

Regards,

Jimmy Deguara

[Mike]

If you can give me a rough year it occurred I should be able to locate it.  There is a vast amount of info and photos but can't pinpoint without a rough date, I keep seeing Pinatubo on the web as the most powerful since one that happened in Iceland.   Have found a South American site with all the volcanoes in all the areas. 

* Was it the Colima volcano?


Mike

[Jimmy Deguara]

It sounds like the one you just said. The pyroclastic cloud was absolutely awesome but this was an aerial video footage view of it. It was on a documentary - Mario Orazem also saw this particular volcano.

Regards,

Jimmy Deguara

[Mike]

Here's some photos of  Guagva Puchincha and Reventador and Etna eruptions - photo credits from http://www.doubledeckerpress.com/pichinch.htm  I'm only seeing space station pics for Colima!

Mike

[Jimmy Deguara]

Mike,

Spectacular indeed. The first two pictures show interesting structure - obviously the first is a capping formation indicating laminar "flying saucer layers" that shows up in the Mt Pinatubo eruption pics but the second is most interesting: a vertical "conical" formation under the main plume updraft. Anyone care to elaborate?

I think timelapse or movie of this eruption may reveal more.

Regards,

Jimmy Deguara

[Harley Pearman]

Dear all

This is one area I am very interested in.

Major volcanic eruptions are capable of causing great change to our weather.

During my tour of the Cascade Mountains NW USA, I went to Mt St Helens which was pluming steam and sulphur clouds about 1 km about the crater. The photos are on my disk. We walked onto Johnstons Ridge and the devastation of May 18 1980 was clearly visible all around us.

The mountain is currently building a new lava dome which is very active. Hence the steam and sulphur plumes I was able to photograph using my new 300 mm ED Nikon Lens. This gives the impression that I am flying over the crater.

The eruptions depicted here are capable of altering the weather as shown by Pinatubo in 1991. (I did not know this thread existed when I placed an article into another thread regarding our unusually cold winter we are having earlier). I have hypothesised that our unusually cold winter for 2007 may be related to a major volcanic blast that occurred at Tungaruhua November 17 2006 in Ecuador. I looked at the sulphur emissions for this volcano which skyrocketed during the eruptions. It could well be related to the sulphur emissions that occurred on this day that has caused a slight but temporary cooling of the southern hemisphere.

There was a massive eruption in 1989 at Lascar in Chile that produced an incredible eruptive column. (Someone wanted to know where it was). I have a photo of it in one of my books. It was not Colima.

Tungaruah (Ecuador) did this on November 17 last year and may be related to our colder than normal winter through the sulphur dioxide emissions. (Any feedback on this would be worthwhile).

Some massive eruptions that have had an incredible effect on global weather includes:-

Laki - In southern Iceland in 1783 that caused hot fogs to occur over Europe. The flood eruption (mainly basaltic lava) caused the death of 1/5 of the population of Iceland and skin peeled off people.

Tambora 1815 - Indonesia. This was a VEI 7 eruption in which 92 kilometres of ejecta was blasted out. This resulted in a major cooling of the northern hemisphere. While it killed 92,000 people, many more were to die from food famines including the potato famine that occurred in Ireland. The temperature of the northern hemisphere fell by 2 to 5 degrees celsius.

El Chichon Mexico 1982. This small volcano roared into life in 1982 and pumped 20,000,000 tonnes of sulphur. Later it was revealed that global temperatures fell by 0.3C on average.

June 1991 Pinatubo. This was a VEI 6 type eruption and the eruptive column towered 135,000 feet during it's climax. It too lowered global temperatures. As a matter of fact at 30 degrees of latitude northwards, the dust cloud was easily visible. I noted it at Armidale in northern NSW at the time.

On tour - June 2007

I visited the site of Yellowstone supervolcano and took numerous photos. In one area, the magma chamber is just 4 km below the surface. It will be the next super eruption that occurs, a VEI 8 eruption.

The magma chamber has a volume of 24,000 cubic kilometres and it is a restless caldera. This is the one to watch. There are numerous monitoring stations there watching it.



 Harley Pearman

[Jimmy Deguara]

Hi Harley,

Concentrating on the imagery for this eruptions here goes including one of the ones you mention



http://fac-staff.seattleu.edu/tomasg/web/reporter/volcano.html
El Chichon volcano erupts in southern Mexico in 1982. (Photo by Tomas Guillen)

Mt St Helens

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Publications/MSHPPF/MSH_past_present_future.html



http://www.swisseduc.ch/stromboli/glossary/plinian-en.html
A plinian-type eruption from Mount Spurr, Alaska, sent an eruption column to a height of about 18 km above sea level (18.8.1992). Photo: © R. McGimsey


http://epswww.unm.edu/facstaff/fischer/research.html
First historical eruption of Anatahan, Marianas (May 2003)



http://volcano-pictures.info/glossary/volcanic_gas.html
Source: U.S. Department of the Interior


http://www.cmar.csiro.au/news/media/2005/3nov05.html
Mt Redoubt eruption,1989, Alaska. Photo J. Clacus

[Mike]

The Redoubt eruption is just simply - well, I'm lost for words on that photo.  Outstanding looking plume - everything you'd want is right there.

Have found your Quito volcano, Jimmy.   Some violent plumes indeed!



Pics courtesy http://english.peopledaily.com.cn/200607/16/eng20060716_283627.html

Mike

[Hung Lo Phat]

Hi all,

What an interesting discussion you've started here. It's very unexpected as plume dynamics (or just plain appreciation) tends to be overlooked by many meteorologists, yet can have such tremendous local and global climatic repercussions. The majesty of large explosive eruptions can be extremely hard to resist and you'd certainly find volcanologists a similar breed to many storm-chasers. You're doing a great job of displaying some of the classic eruption photos here and I've noticed a few queries appear that I'd be keen to discuss.

I saw Jimmy mention the conical formation in the Reventador photo. To me, this looks like ash falling from the upper plume, in front of the main eruption column and fining out during descent (note the diffuse lower edge). Reventador looks to have experienced a minor eruption in 2007, although the last official period of activity spans 2004/05. The photo shows Strombolian-style activity, as opposed to the extremely vigorous Plinian activity illustrated in many of the other photos. Strombolian eruptions are pulse-like in character as volatile gases build under a cool, hardened 'slug' of material in the volcanic edifice, with the eruption occurring once the gas pressure exceeds the deformation threshold of the magma. This kind of behaviour certainly could create a situation where you'd witness a small plume with lofted materials sinking in close proximity to the main updraft. With your experienced eye, would you consider this feasible?

Harley, aside from recounting enough classic eruptions to make a hazard scientist gush, was curious about the effects of the 2006 Tungurahua eruption upon the Australian climate. I think you may be scratching on this correlation Harley, since the eruption was not strong enough to produce stratospheric injection of aerosols. Without that, highly-soluble sulphur dioxide would rapidly be washed out of the local atmosphere as acid rain and the climatic effects would only be local. You mentioned several significant climate-influencing events; Laki, Tambora, El Chichon, Pinatubo, all of which had colossal eruption rates, towering Plinian eruption columns (some in excess of 40km, which is pretty staggering for those convection experts here) and high aerosol content. All are considered to have significantly altered global climate and stratospheric injection of material of high aerosol content is the common factor.

Something I find fascinating are the reports of incredible lightning emanating from eruption columns and pyroclastic flows. Volcanic lightning is seldom researched or even mentioned in the academic literature and is a topic befitting of discussion here. I've always wondered whether the intensity of the strokes would differ from those formed in thunderstorms, given that volcanic lightning arises from collisions of fine ash. I'd imagine that there would be little difference because the path would remain the same i.e. the resistance of the air would be the factor to overcome and a flash would occur once this was breached. Any ideas?

Cheers,

Olly

[Mike]

Here's a great black and white photo of an impressive eruption.
Pic acknowledgments to  http://volcano.und.edu/vwdocs/vwlessons/kinds/kinds.html

Ed:  Moved topic of volcanic lightning to carry on a new thread

Mike