The volcano Etna has been on Sicily for more than a million years, longer than human beings have inhabited the Mediterranean. It has been erupting nearly continuously throughout 3500 years of recorded history, since 1500 BCE, and doubtless for long before that.
Etna has had hundreds of recorded major eruptions; another began with the eruptions of spring 2001. And like the hundreds of times before, the local people responded in the ways they always have. But modern technologies have allowed them to respond a bit more effectively, and with a bit less resignation, than before.
Etna Then and Now
Etna is such an important volcano that the ancients made it the home of Vulcan, blacksmith to the gods. Like the personality of Vulcan himself, Etna is always unpredictable, often gloomy and irritated, sometimes dangerously angry, even on rare occasions playful. All of the seafaring peoples of the ancient Mediterranean knew Etna as a steady beacon and landmark, looming near the strategic Strait of Messina at Sicily's eastern tip.
People have always lived near Etna, even upon its sides. The same is true with volcanoes around the world. After all, volcanic ash weathers into rich soil, and the risk of injury or death from an eruption is pretty small. On many volcanoes, you can live your whole life without witnessing an eruption—or if there is one, it won't destroy your part of the mountainside. That's the kind of risk we all accept about the place we live, whether it's prone to earthquakes, hurricanes, sinkholes, or landslides.
The 2001 eruption of Etna made news not only because it was a great spectacle, but because there was human drama as well. The lava engulfed an important skiing and tourism center on the mountain, the Rifugio Sapienza. Nowadays we don't just send prayers to our current gods, as the ancients did—although the archbishop of Sicily did just that in 2001. Today the Italian authorities send bulldozers to throw up barriers to the lava.
Acting Against Volcanoes
We've tried other things against volcanoes, too, such as military bombing to divert lava flows. When a volcano threatened the Icelandic town of Westmanneyjar in 1983, the main tactic was spraying the lava with seawater to freeze it solid.
But the first successful defense against a volcano was here in Catania, the city of half a million at Etna's foot. In 1669, the Monti Rossi vent on Etna's southern flank began pouring out a river of lava uphill from Catania. The city's existing walls held back the flood for a week. But after part of the wall gave way, the authorities built new walls in the city streets that were effective against the lava's advance.
Another tactic tried in 1669 was to break open the roof and sides of the lava tube feeding the flow. It was hoped that this would cool and freeze the molten rock, as well as directing part of the flow elsewhere. The nearby town of Paternò felt so threatened by this measure, it sent out an armed force to stop the work crews.
As a result, laws were enacted to forbid tampering with lava flows. These remained in effect until 1983, when more modern techniques were allowed. So the bulldozers of today are still an experimental technology when it comes to fighting eternal Etna.
Another experimental technology was tried at Etna in 2009: gas sampling by remote-controlled helicopter. The Scots geologist whose brainstorm that was won a Rolex Award for Enterprise in 2008. Remote-observation techniques like this promise to spare volcanologists from some of the danger inherent in their work while helping in eruption forecasts.
PS: The Etna eruption, among other things, produced a small quantity of Pele's hair. This fine-fibered volcanic glass is more familiar from Hawaii, where the liquid basaltic lava is readily blown in the wind.