Fine ash can travel farther than the heavier stuff, but still does a lot of harm to engines if encountered in significant quantities.

ECONOMIST: Volcanoes and air travel: Small eruption in Iceland | The

Two factors have contributed to the high volume of fine ash.

ECONOMIST: Volcanoes and air travel: Small eruption in Iceland | The

But that does not mean the volcano produced fine ash continuously.

ECONOMIST: Volcanoes and air travel: Small eruption in Iceland | The

But a combination of circumstances meant that, though comparatively small, Eyjafjallajokull's current eruption punched above its weight in the ash-production league in its early days, emitting much more fine ash than is normal.

ECONOMIST: Volcanoes and air travel: Small eruption in Iceland | The

As we approach the elephants, he takes out a small plastic squeeze bottle containing fine white ash and puffs some into the air, gauging the breeze.

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The Swach's cartridge, a key component of the system, resembles Edison's electric bulb and is made up of a composite of rice-husk ash (a highly porous material derived out of paddy husk) and fine particles of nano-silver, which inhibits bacteria growth.

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