The violent electrical storms that break as a volcano erupts mystify scientists. David Adam reports on a new explanation for the explosive phenomena - and the surprising amount of water in magmaIt must be the greatest light display on Earth. The most vivid demonstration of power,beauty and mystery the natural world has to offer. And it must be terrifying to witness at close quarters. In fact, the greatest mystery approximately the phenomenon of volcanic lightning is how, and with every instinct urging them to rush like the clappers in the opposite direction,anybody hangs around long enough to see it.
There are now more than 150 recorded cases of vicious electrical storms breaking out directly above craters of erupting volcanos, dating back several centuries. The 1980 eruption of Mount St Helens in Washington state, and one of the most studied eruptions in recent times,produced a lightning bolt every moment. The electrical activity does not pose the same hazard as a volcano's boiling lava, choking dust clouds and drowning mud slides - though there are reports of people and animals being struck as they fled - but it sets a spectacular seal on mother nature's most awesome display of destruction.
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Source: theguardian.com