Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: colarris on 21/04/2010 22:56:21

Title: Why is lightning associated with volcanoes?
Post by: colarris on 21/04/2010 22:56:21

 
 I've noticed in recent pictures of the volcanic eruption in Iceland that there are streaks of lightening across certain parts of the ash cloud coming from the volcano. What is causing it?

Title: Re: Why is lightning associated with volcanoes?
Post by: LeeE on 21/04/2010 23:27:18

Exactly the same thing that causes lightening in thunderstorms: static electricity due to lots of very small particles rubbing together.  In thunderstorms the small particles are droplets of water but in volcanic eruptions the particles are micro-fine rock and/or glass 'dust'.

Many industrial fires and explosions have occurred due to a buildup of static electricity in processes that deal with a lot of 'dust', ranging from wheat flour to iron rust.