cool pic

clipped from photo caption " Cases of electrical storms breaking out directly above erupting volcanos are well documented, although scientists differ on what causes them. Picture taken May 2, 2008. "

I'll guess.. (My crappy physics is going to show :P ..)

1) Ash friction against clean air creating a charge difference. Kinda like rubbing fur on a plastic comb. 2) It's like creepage on circuit boards.. Just some crap creating a path of least resistance between a large potential(sky to earth). Ash air probably conducts better than clean air. 3) Can batteries exist in gas form? Acidic gases and vaporized dissimilar metals? Nahh... 4) Charged ash..?? Would hot magna be releasing electrons and the ash collects the electrons. The negatively charged ash rises and builds up and then discharges to earth. 5) The ash turbulence somehow makes a large potential. A little like when helicopter rotors that create an electrical charge.

D from BC British Columbia Canada

Remember that the rising steam and other gases are rising faster than the rock particles it is lofting. When the rock particles bump and separate, I think electrons are released into the passing gas stream (a triboelectric effect

). This is taking place all the way up the bore of the volcano and continuing to the top of the plume.

This charge pumping processes eventually produces a massive charge separation that is restored by a blast of lightning back down the rising column (with lots of filaments collecting charge converging from many parts of the plume). One of those photos shows the massive arc concentrated down into the main jet at ground level.

It is a massive electrostatic generator.

--
Regards,

John Popelish

: :

: :John

Sounds like an invite to come up with a bigger and better lightning shot :-)

and there's some real beauties here

Is there a special way to photograph lightning?? Is it a light activated shutter? Perhaps a EMI burst activated shutter? (ex: AM radio) Take a zillion photos and hope to get lucky?

Photoshop ?? :P

Lightning is rare in BC. When it does happen it can be spectacular. One night I noticed about 1 flash per 30sec. Very unusual in 10 years time.. I knew it was lightning and wanted to check it out.. Park? Beach? Ahhhh...the airport! YVR I was the only person on the side of the road watching the lighting near the airport. Soon others stopped and watched.. "Hey..look at that idiot standing out there watching the lighting...Let's check it out..'

About 30 people pulled over and got out to watch the nature show. :)

D from BC British Columbia Canada

Well, you need to close the aperture to minimize light sensitivity, set exposure to say 10-20 seconds, often also add a ND "dark filter" to further minimize sensitivity, also set ISO low (say to a 100). Of course use tripod.

Than all you need is some luck and patience. I've got some pretty good shots, but the lightning itself is a bit over-exposed, I've got ND filters to fix that this year. Eagerly avaiting some storms...

It can be scary and dangerous if you're too close (and too high, say on a small hill), storms can move very quickly.

Mark

Ah, there's a picture like that on the cover of my textbook. Lots more red, it was a firey eruption photographed at night. Book is: Halliday, Resnick, Walker, _Fundamentals of Physics_, 6th ed., John Wiley & Sons, Inc. (2001) Says cover photo: Tsuyoshi Nishiinoue / Orion Press This photo is used as the basis of Chapter 23, which starts with: "During the frequent eruptions of the Sakurajima volcano in Japan, multiple electrical discharges (sparks) flash over the volcano's crater, lighting up the sky and sending out sound waves that resemble thuunder. However, this is not a lightning display in a thunderstorm, with electrified clouds of water drops discharging to the ground. This is something different."

So here's the mountain,

And I won't quote the entire explanation, but the important part given is: "...Ash results when liquid water within the volcano, suddenly converted to steam by the flow of hot lava, shatters rock, which is then burnt. The liquid-to-steam conversion and the explosion of rock cause positive and negative charges to seperate. Then, as the steam and ash are spewed into the air, they form a cloud that contains pockets of positive charge and pockets of negative charge."

So there ya go, D f BC ;-)

Tim

-- Deep Fryer: A very philosophical monk. Website @

Ahh.. there's an idea for a romantic evening with the girlfriend. Now I can take her to an active volcano at night and explain how the lightning is formed. If it's not her idea of romance, at least I'll be turned on.. :)

D from BC British Columbia Canada

Head up near Prince George in early August and you should be able to catch some pretty good shows.

Oops... I didn't mean all of BC. I've not aware of what the lightning is like in other parts of BC. My experience is just from the Lower Mainland and Fraser Valley where most of people are living.

Example: Vernon BC lightning

D from BC British Columbia Canada

And if it is, you might have to marry 'er.. :)

Tim

-- Deep Fryer: A very philosophical monk. Website @