Bardarbunga, photo in P.D. by Peter Hartree

Yesterday’s odoriferous eruption of Iceland’s Bárðarbunga volcano got me thinking about the nasty stuff just below our feet. The volcano has begun gassing smelly poisons and the scent of Iceland’s rotten eggs has been whiffed as far away as Finland. Why are volcanoes so often sulphur-tinged?

Well, sulphur is pretty universal. Astrophysicists figure it is cooked up in the deeper ovens of the larger stars. Or anywhere that temperatures exceed 2 billion degrees and pressure is sufficient to fuse silicon and helium into elemental sulphur. Once formed, expelled, and extruded into nascent solar systems, naturally occurring sulphur seems tame – yellowish and often crystalline. At its most pleasant, it looks like the sample in the picture on this page. If there was ever an industrial element, sulphur would be it. Almost all the sulphur produced in the world comes to us as a by-product of oil refining and its commercial uses include gun powder, matches, fireworks, insecticides, fungicides, and fertilizer for agribusiness. Sulphur is one of the essential elements of life, both animal and plant – which is why the biggest commercial use for sulphur is in fertilizer.

This stuff is frequently distilled and concentrated by heat, water, and the pressure of blossoming volcanic buds.  Then it is blasted into the atmosphere. Its reeking odor can permeate the cabin of a passing plane. If accompanying volcanic ash doesn’t bring the craft down, inhalation of sulfur dioxide, even at low concentrations, can make most people sick. Or worse.  And when sulfur dioxide joins water, sulphuric acid is formed. Its an acid that can damage aircraft windows, build up sulphate deposits in engines and strip the paint off the once shiny surface of wings. Sounds grim. Earth is not the only place that deals with volcanic sulphur.

Jupiter’s closest Galilean satellite, Io, is the most geologically active object in the solar system. Tidal pressure from its nearby mother planet generates enormous heat. This creates volcanoes known to spew sulphur 500 kilometres above Io’s surface, which is mostly volcanic mountains and plains coated with yellow sulfur and sulfur dioxide frosting. With all that heat and sulphur, Io may be the refuse pile for lost souls.

God’s Wrath: Destruction of Sodom and Gomorrah, painted by John Martin, 1852

Brimstone is an old word for sulphur. Means exactly the same thing. You’ve heard of fire and brimstone. Maybe you’ve even attended a weekend morning lecture on the subject. There are places all around our town that offer introductory lessons on the downside of ending up in pits of fire and brimstone. The Torah authors knew how to sometimes describe the foul and frightful. Ever wonder what God’s breath smells like? Not coffee. Isaiah 30:33: “The breath of Jehovah is like a stream of brimstone.” In 1712 BCE, God destroyed Sodom and Gomorrah with fire and brimstone. Probably with his angry morning breath.

Which brings us back to Bardarbunga (sometimes called Bunga-Bunga by geologists in the know). What has Iceland been up to that it has been getting smacked by the personal breath of God? Whatever it is, the Bunga-Bunga eruption within the Holuhraun lava field has been emitting smelly volcanic gases (sulfur dioxide, carbon dioxide and hydrogen sulfide) for weeks. For years. For many centuries, actually. This is just the latest gasp in a very long Icelandic saga.