iceland and volcanoes -- 6/3/2026

03 Jun 2026

iceland and volcanoes -- 6/3/2026

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Today's encore selection -- from Mountains of Fire by Clive Oppenheimer. The smoldering volcanoes of Iceland made some in the past regard it as the authentic location of purgatory:

“Iceland is nothing short of a volcanologist's paradise. You cannot find a stone in the country that wasn't expressed through a volcanic orifice. The country is a gigantic volcano. One or another of the island's innumerable craters erupts every few years: over 200 events are catalogued for the period since the Vikings (and a few Celts) settled there around the year 870 CE, and the true figure may be closer to 300. With so much opportunity for igneous encounters, it is unsurprising that human fantasy and frailty are deeply engrained with experience of volcanic vistas and convulsions.

“The island straddles Earth's longest mountain belt, the Mid-Atlantic Ridge, which spans the dark ocean between the polar regions. The ridge is forged from a partnership of volcanism and tectonics that continuously renews the Earth's crust. In the North Atlantic, it divides the Eurasian and North American plates, which move apart two centimetres per year, creating a rent that is filled in by eruptions of lava along the sea floor. Worldwide, the new seabed created every year by this process of 'sea-floor spreading' adds up to an area about the size of Central Park in New York City. The Earth isn't expanding, so a comparable amount of ocean plate is consumed at subduction zones like the one offshore from Chile.

“Beneath Iceland, the volcanism is supercharged by the melt expressed from a hot current of solid rock, known as a mantle plume, that rises slowly through the Earth. Instead of lying one mile below the waves, as does much of the ocean ridge, Iceland's peaks reach as far above sea level. The result is an exposed tectonic plate boundary revealing parallel and cross-cutting fault escarpments, lava plains and countless volcanoes.

“Icelandic volcanism achieved global notoriety in 2010 with the explosions of Eyjafjallajokull in the country's south. The intermingling of red-hot magma and glacial meltwater generated uncommonly violent blasts that shattered lava into powder. The ensuing clouds of floury dust headed for European airspace. Ever since a British Airways jumbo jet lost power in all four engines as it flew through an ash cloud over Java in 1982, the International Civil Aviation Organization has been braced for similar encounters. It established nine Volcanic Ash Advisory Centres, hosted by national weather services around the world to monitor and advise on the threat. All the same, the Eyjafjallajokull eruption caused global disruption to flights with economic losses counted in the billions of dollars.

The eruption on 27 March 2010

“While this 'ashpocalypse' raised awareness of the airborne menace of explosive eruptions, we should take note of a more insidious peril of Icelandic volcanoes: lava floods. They armour the cone of a volcano but then ooze into lowlands, ravaging vast areas of farmland and pasture, infilling the nooks and crannies of a landscape like a gigantic road resurfacing project gone horribly wrong. While explosive eruptions can begin abruptly and end in hours, giving little time to react, lava flows and floods tend to be more staggered and prolonged affairs, impacting first one locale, then another. This has elicited a variety of invocations and confrontations intended to stem or divert lava, or even to stop it bursting out of the Earth in the first place. The outcomes, though, have not always desirable.

“Lava flows seldom kill people directly — they don't move at the speeds of nuées ardentes, and you'd have to be incredibly stubborn or unlucky for one to outrun you. But they can pump phenomenal quantities of gases into the air, which can scorch and poison a much wider area with acid rain and fluorine (a little of this in your toothpaste is beneficial, but it is extremely toxic at high levels). This can despoil productive land, and it is in this way that lava eruptions have claimed far more lives through famine and disease than any explosive eruption in Iceland. More than that, the sulphur emissions from the largest Icelandic lava floods in history have cooled climate and triggered food shortages across the Northern Hemisphere in much the same way that Mount Tambora did in 1816, despite being very different kinds of eruption.

“The best understood example of a lava flood in Iceland is the Laki eruption. Its noxious emissions of gas and ash and the great tongues of lava that flowed into the lowlands devastated the food economy of southern Iceland. A fifth of the country's population perished from malnourishment and disease during what Icelanders refer to as the 'haze famine'. The eruption persisted for months, and the haze became a 'universal fog' that spread over Europe and beyond in the summer of 1783. The statesman and polymath, Benjamin Franklin, attributed the severe European winter that followed to the airborne dust, while his contemporary, Erasmus Darwin (Charles's grandfather), thought it responsible for an 'epidemic cough'.

“Iceland's volcanoes were known to the outside world long before Eyjafjallajokull and Laki exported their effluvium. For centuries, Europe had been importing sulphur, mined from the country's geothermal spots. It was initially sought out for medicinal purposes, but its use in the manufacture of gunpowder made it increasingly popular. Oddly enough, those dispatched by the firearms that made use of this explosive would, according to medieval theologians, have ended up in Iceland — in death that is — within one of its most active volcanoes, Hekla. Situated north of Eyjafjallajokull, it was regarded as the authentic location of purgatory.”