Topic: Volcanic lightning discussion

[Mike]

Ed: Decided to move topic to this thread to ease congestion as this is a little different from the volcanic cloud topic.

This snippet below on how lightning may form within the plume or even magma came from this site - and you can read the report an theory behind what was asked earlier about volcanic lightning. 

http://education.guardian.co.uk/higher/research/story/0,9865,1369252,00.html

'.....Now, an intriguing new idea that could explain volcanic lightning has emerged. Earle Williams of MIT and Stephen McNutt at the University of Alaska, say it might simply be caused by a build up of ice. Because thunder and lightning in conventional storms are down to ice and water, the two claim that large volcanic eruptions are nothing more than dirty thunderstorms.'

[Jimmy Deguara]

Hi Mike,

Admittadely, this is the first time I have ever observed a picture of lightning associated with magma. Thanks for the explanation link as well - will have to approach this when I get a chance.

Kind regards,

Jimmy Deguara

[Mike]

I was fairly surprised also!  If you can have lightning sparked by ash, rocks hurled upward within the violent 'updraught' of the volcanoes eruption, it seems all the magma within this cloud also has a role to play.  I'll be definitely searching this one out.  What do you think Harley et al?

Mike

[Hung Lo Phat]

Hello again,

Sorry if I started to confuse topics on the other thread - I may have gotten a little carried away there!!

Here's documentation of another type of volcanic lightning all together - a low energy variant associated with the rapid exit of material from the vent region. This is particularly interesting as it seems to hint at a completely different source from the more thunderstorm-like variety hinted at in Mike's Guardian article.

http://www.sciencemag.org/cgi/content/abstract/315/5815/1097 - sadly only an abstract without a subscription
http://environment.newscientist.com/channel/earth/dn11250-erupting-volcano-crackles-with-lowenergy-lightning.html - a synopsis of the aforementioned article

So it seems that the current explanations for charging of volcanic plumes are:

A. the interactions between ash particles causing a static buildup
B. ash acting as condensation nucleii for magmatic water which then accretes as ice via riming. Charging then occurs as in a thunderstorm
C. a piezoelectrical source due to the fracture of crystals upon eruption

Perhaps we can add to this list, if more explanations are known about? Gather some sources to fuel our interest and discussion.

Cheers,

Olly

[Michael Bath]

I found this image in the National Geographic Magazine January 1981 edition. Photo by Jack Joyce.

The scan shows lightning associated with the eruption of Mount Mt Helens at Glenoma, Washington. The eruption was 20 miles to the south.

Was a bit hard to do a good scan due to the photo spanning two pages.

[Mike]

Quite okay Olly.  There's so much to talk about on this topic that the thread will get confusing when trying to locate comments within comment to reply!

Located these two photos that are just brilliant.  I'm very impressed with what looks like a distinctive CG from the anvil created by the ash plume in the second photo.  This must corrolate the dynamics of ash plumes and thunderstorm towers - anything, no matter how tiny if hurled around at great speed will create a discharge!

 Photo acknowledgment to http://commons.wikimedia.org/wiki/Image:Rinjani_1994.jpg

Mike

[Mike]

Not sure if this is caused by the volcano - looks as if there's storm activity around it.  Nevertheless another beautiful photograph from http://www.arenal.net/arenal-volcano.htm

And this explanation also courtesy of... http://environment.newscientist.com/channel/earth/dn11250-erupting-volcano-crackles-with-lowenergy-lightning.html

'A new kind of low-energy lightning has been discovered, crackling and sparking in the mouth of an erupting volcano.

Traditional, thunderstorm-style lightning has long been associated with volcanic eruptions. As large plumes of ash and rock rise into the air, oppositely charged particles separate into layers. These layers build until the difference between them is great enough that a connection forms, releasing energy in a flash of electricity.

But in a new study researchers have shown conclusively that a new form of low-energy lightning is also active during eruptions, arcing between particles as they exit the volcanic vent at around 100 metres per second.

Ronald Thomas at New Mexico Institute of Mining and Technology in the US, and colleagues, used two receiving stations to monitor a series of short eruptions from the Mount St. Augustine volcano in Alaska, US, in January 2006. They detected a persistent "background" radiation emanating from the volcano’s vent which they believe is the product of nearly continuous sparking and miniature bolts of lightning tens of metres long.

The low-energy lightning forms differently than thunderstorm-style lightning. Rather than neat layers, the force of material exploding from a volcano’s vent causes chaotic charge build up.

“When particles bang into each other, they exchange mass and electrons,” says Thomas “But the electrons don’t get distributed evenly, so a charge is formed.”

Steve McNutt, a team member at the University of Alaska, US, believes the work will prove useful as an added dimension of hazard assessment, especially in issuing advisories for planes, which can be severely damaged by flying through volcanic plumes. “We now know that we can detect the presence of a volcanic plume” at night and before it can be detected visually, he says.

Journal reference: Science (vol 315, p 1097)


Mike

[Hung Lo Phat]

Unbelieveable volcanic lightning eminating from Chaitén's plume in Chile - some of the most incredible pictures I've seen to date. Well worth a look.

http://megagalerias.terra.cl/galerias/index.cfm?id_galeria=30734

[Jimmy Deguara]

Hung Lo Phat,

You are right - well worth the look! Absolutely spectacular and something one would dream to be able to do - capture lightning produced by a volcanic eruption.

Regards,

Jimmy Deguara

[Harley Pearman]

I have never looked at the dynamics of this but I have resource material suggesting that lightning during volcanic eruptions are more likely to occur during explosive volcanic events rather than eruptions involving wholly the out pouring of molten rock.

That is, the events are more likely from grey volcanoes rather than red volcanoes.

Red volcano:- Defined as a volcano that emits lava only.
Grey volcano:- Emits ash clouds, plumes and and ejecta (Explosive volcanoes).

Actually a person called Pliny The Younger (AD 79) - Eruption of Mt Vesuvius, August 24 AD 79 mentions such an event. This eruption thanks to his superb work made a record that when the eruption commenced, he accurately estimated the height of the eruptive column reasonably well (Around 20 km) but mentions lighting occurring within the eruption. He mentions quote "On the other side, a black and dreadful cloud bursting out in gusts of igneous, serpentine vapour now and again yawned open to reveal long fantastic flames, resembling flashes of lightning, but much larger". (Raging Planet by Bill Mc Guire 2002).
 
This person in his works mentions lightning occurring during the eruption and it has been found to be accurate.

Another historical documentation of it is from a person called W J Watson who logged the details of a VEI 6 type eruption in 1883 called Krakatoa (Indonesia) as he sailed past that island the night prior to two thirds of the island being blown to pieces. He writes on August 26 1883 of a gargantuan eruption and a hail of hot pumice and frightening bolts of lightning leaping back and fourth between the sky and the island. He also mentions a phenomena called St Elmo's fire as well in which an eerie glow enveloped the ship - The Charles Bal with pinkish flames within the rigging. (Volcano, George G Daniels 1989)

Again his writing was accurate and this would later be explained as an atmosphere super charged with static electricity.

There have been many more instances of this including a famous one in Japan in 1995 being Sakurajima. I think some detail research was done on this but I need to look more closely prior to providing another post on this topic.

Other instances include Mt St Helens (1980 in Washington State USA) and Surtsey (1963 off south coast of Iceland). A major lightning storm was photograped during the explosive phase of the eruption particularly as the island was rising out of the water.

Harley Pearman

[Ursula]

Hi there,

Chaiten Volcano is putting on a display after 9000 years or so, which one is next, as the saying goes, as above, so below, southern hemisphere now he northern will have a go in the next 3 month or so.

Also when theyre are storms about, I noticed there is usually a more pronounced display over the peaks of Volcanoes dormant, extinct or otherwise.


***

Earth and sky in electrifying battle of the elements

By staff writers

May 08, 2008 03:03pm
Article from: NEWS.com.au



TWO spectacular forces of nature seemed to be meeting in the skies of Chile yesterday as a volcanic eruption caused a lightning storm.

It may have looked like the storm was passing the Chaiten volcano but  the lightning was caused by the static charge created by the friction of rocks and ash thrown into the air, The Times reported.

The result was an extraordinary sight as lightning flickered around the dust cloud in the fiery, orange glow of the volcano.

Geoscience Australia's Alanna Simpson said the lightning storms were common in eruptions were lots of material was thrown into the sky.

"As long as there is a similar amount of of ash in the air and similar weather conditions there is no reason why it could not continue," she said.

Ms Simpson said in the 1994 eruption at the Rabaul Caldera in Papau New Guinea one person was killed by a lightning strike generated by the ash cloud.

The Chaiten eruption was all the more spectacular because the  volcano, 1300km south of Santiago, has been dormant for hundreds, if not thousands, of years, The Australian reported today.

The volcano, whose eruption has forced the evacuation of 4000 nearby residents, is part of a string of volcanoes running along the so-called Ring of Fire - an arc of active volcanoes extending north from the west coast of the Americas across the Alaskan-Siberian rim and south to Indonesia.

Chile hosts the second-most active volcanoes in the world behind Indonesia.

The Chaiten volcano began erupting on Friday. But the violence of the event increased dramatically yesterday as dust, gas and lava blasted fiercely out of the volcano, spreading ash across the region.

Residents living closest to the eruption were forced to use facemasks to avoid inhaling the ash, which is up to 15cm deep on the ground in some areas.

Chile's National Emergency Office said fine ash was still falling and that visibility was poor.

Interior Minister Edmundo Perez Yoma said: "We don't know if this is a situation that will last days or weeks or even more."

[David C]

Some great photos of lightning from this event - took me a few minutes to convince myself that they were not photoshopped:

http://www.metsul.com/blog-24hs/?cod_publicacao=330

[Mike]

What about this baby shown in The Australian newspaper - just incredible!!!!  Thunderstorm moving over an eruption and look at the massive amount of lightning just smothering the plume....oh..my God.  Surely this must rate as the most impressive eruption image ever taken.  I just can get my head around the amount of electrical activity surrounding the plume or updraught area - who said particles of ash don't make excellent mixing for lightning - phew!

[Hung Lo Phat]

Don't think that's actually a storm producing the lightning there Mike. Volcanic plumes are notorious for their fearsome lightning displays due to the immense amounts of static created from all that convecting ash.

[Mike]

No, actually I did mention the plume - volcanic plume I was eluding to.  The storm was overhead but yes, for sure the volcano produced the immense lightning discharges due to the enormous updraught of the ash tower.