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26 June 2019

Why we should like volcanoes



This article was written by Bill Prast. All views and opinions are strictly his own.


Coming back from a recent short visit to eastern Sicily, it seemed the Catania airport was less busy than usual, perhaps because its neighbour Mount Etna has been in the news again.  Thanks to drones  we have been seeing photos of red-hot lava flows and big ash clouds.  Maybe some anxiety-prone tourists were postponing their visits.

But Etna has been burping away for several hundred thousand years.  All this time, the mountain is slowly sliding into the sea at the rate of several centimetres each year.  What might happen in the distant future is unpredictable.  Some day there may be a massive collapse, it could explode and do untold damage to the region.

Meanwhile, the Mediterranean has already had its share of catastrophic volcanic eruptions in recorded history.  Vesuvius and Pompeii spring to mind, when maybe one thousand people died.  There are three million people in Naples and nearby Campania today who would be in deep trouble if Vesuvius erupted again.

And then there was the total destruction of the Greek island of Santorini, almost four thousand years ago.  We know it was an advanced civilisation and it gave us the legend of Atlantis.

The damage from major volcanic incidents elsewhere were sometimes much worse.  When Krakatoa blew up in the late nineteenth century, it threw ten cubic miles of rock and ash twenty kilometres straight up in the air, into the stratosphere actually, and killed 35,000 people on Java, Sumatra and other islands, from the blast and from tsunamis.  It was ten thousand times the size of the Hiroshima bomb.

In 1980, Mount St Helens in Washington state blew the top four hundred meters off the summit.  It was far enough away from Seattle and Portland, Oregon to not be a threat to those places, unlike Vesuvius is to Naples today.

And in 1991, Mount Pinatubo on Luzon island in the Philippines expelled a vast amount of ash and poisonous gas.  Luckily there were several weeks of early warning signs of danger which meant many thousands got to safety.  Nevertheless the countryside people living on and near Pinatubo lost all they had.

So volcanoes are scary and may not have the best of reputations, but from the standpoint of the metals business they are essential.

In my student days, I took a course taught by an eminent volcanologist who said the only real rocks are the igneous ones created from volcanoes and all the other rocks, the metamorphic and sedimentary stuff like granite and sandstone, are nothing better than debris crunched up and pulverised over time from what were once nice igneous rocks.  To him, they’re derivative and merely recycled garbage.

In short, geoscientists, mining engineers, metallurgists and metals traders can all be thankful for volcanoes having provided economic ore deposits for us to find, produce, process and sell.

Furthermore, we wouldn’t have the Hawaiian islands if it weren’t for them.  Or Madeira and its archipelago.  Not to mention the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha in the South Atlantic  All of them were or still are volcanoes.  Where would they have exiled Napoleon without Saint Helena?

Then there’s Iceland.  It’s got at least a hundred active and inactive volcanoes.  Some eruptions have been large enough to create new offshore islands, gradually making the country somewhat bigger.

Iceland is not the only country that ought to be thankful for them.  The French should be, too.  Ages ago central France was an active volcanic area and today the mineral water companies sell you bottles of water made delicious by having percolated through multiple layers of volcanic rock.

Moreover, volcanoes are a plus because the lava, ash and whatever else come out of them provides highly fertile soils, ideal for agriculture.  Etna is a prime example.  The lower slopes are covered with orchards and vineyards and groves.  Almonds, pistachios, citrus fruits, olives and of course grapes which yield an excellent range of wines.

And whenever you enjoy a plate of Italian pasta, recall it is made from durum wheat farmed on volcanic soil.  All in all, volcanoes are okay with me.

To paraphrase the English poet William Cowper, nature moves in mysterious ways, her wonders to perform.




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