In planetary terms, it was just a tiny pinprick that opened up last month underneath the Eyjafjalla Glacier in southern Iceland, when a long-forgotten volcano started to erupt again after a quiescence of nearly 200 years. But insignificant though the rent in the planet’s fabric may have been, uncounted millions have been suddenly affected by it.


The North Atlantic winds shifted by just a few degrees, and all of a sudden commercial catastrophe has been visited on northern Europe: air traffic peremptorily shut down, the skies cleared of planes wary of flying through the high-altitude streams of the volcano’s brutally corrosive airborne silica dust.

The last time the world was so mightily affected in this way was in 1883, when a similarly tiny vent in the earth’s surface opened up on the island of Krakatoa, between Java and Sumatra, in what is now Indonesia. Some 40,000 people died because of that eruption — it was a much more fierce event, and in a much more populated place. But the clouds of dust that cascaded upward into the stratosphere affected the entire planet for the rest of the year on the same scale — except that the effects themselves were of a profoundly different kind.

Krakatau (or Krakatoa) present day

Where Iceland’s volcano has set off a wave of high-technology panic, Java’s event set off something benign and really quite lovely: worldwide displays of light and color that reduced mankind to a state of stunned amazement. Where Iceland has caused shock, Java resulted in awe. And where Eyjafjalla’s ashes seem to have cost millions in lost business, Krakatoa’s dust left the world not just a remarkable legacy of unforgettable art but also spurred a vital discovery in atmospheric science.

The skies in the fall of 1883 became weirdly changed. The moon turned blue, or sometimes green. Firefighters in New York and elsewhere thought they saw distant fires, caused by clouds of boiling dust. The vivid ash-tinged sunsets, and the post-sunset horizon rainbows of purple and passion fruit and salmon-red, were said to be the most memorable.

Painters in particular did their best to capture what they saw. An obscure Londoner named William Ascroft, astonished by the nightly light show along the Thames, turned out a watercolor every 10 minutes, night after night, working like a human camera. More than 500 Krakatoa paintings survive him. “Blood afterglow,” he jotted down on one canvas, noting the magic done by refractive crystals of dust; “Amber afterglow,” on another.

Grander artists, like Frederic Church of the Hudson River School, were spurred to action too. In December, four months after the Javanese blast, Church hurried up from Olana, his Moorish castle near Poughkeepsie, to Lake Ontario, and one perfect evening caught the vivid crepuscular purples over the ice on Chaumont Bay, knowing full well — as science already did — that it was a volcano 10,000 miles away that had painted the sky for him.

And one even more famous painting speaks of Krakatoa as well: recent research suggests that Edvard Munch a decade later painted “The Scream” while remembering a night in Oslo that had been much affected by the volcanic dust. Indeed, the climatic records show that the swirling orange skies behind the terror-stricken face match perfectly those recorded that winter in southern Norway.

It was more than art that resulted from Krakatoa’s outpourings of trillions of tons of fine siliceous ash. It left a lasting effect on science as well.

The heavier dust from Krakatoa slowly fell to earth, coating ships and cities thousands of miles away. But the micron-sized particles from the volcano’s mouth did not fall back at all. Instead, they were carried ever upward, and ended up floating around the world for years, on streams of globe-girdling winds that were not then even known to exist.

Weather-watchers, carefully noting just when certain skies in certain cities were inflamed and colored by the passing high-altitude dust clouds, produced a map showing just how these wind currents moved around the world. The first name they used for the phenomenon was the “equatorial smoke stream.” Today it is, of course, the jet stream — a discovery that remains perhaps the most important legacy of Krakatoa.

It is a legacy that, like the night-sky art, remains somewhat more memorable than the flight-cancellation lists at London’s airports, which will probably be the most lasting public memorial of the little-volcano-that-roared on the southern flank of Iceland.

Simon Winchester is the author of “Krakatoa: The Day the World Exploded” and the forthcoming “Atlantic: The Biography of an Ocean.”

Source: New York Times