Vesuvio

You say Vesuvius, I say... Vesuvius the classical name; Vesuvio in modern Italian.

You can climb it, but it's a long way. Buy a bus ticket at the Pompeii Sclavi station on the Circumvesuviana railway. The bus takes you about half-way. (Incidentally, the countryside around here is incredibly messy: rubbish, domestic and building, gets dumped everywhere.) Half-way up you transfer to a bus-jeep which takes you lurching up through the beautiful National Park forest. When that peters out you climb the last ten minutes up to the crater. Vesuvio is about 4,000 feet. My water bottle exhales a brief sigh as I open it.

A short lecture from a volcanologist (included in the ticket), and you are free to wander around. Go early: it gets crowded. It's a huge hole in the ground. Not much more really, but really huge, awesome, with vertical sides, a massive 600 metre-wide cannon. In the last eruption (1944) it managed to block its vent with 8km of rock. But the magma chamber is still there below that, and as the pressure builds up, more gas is produced. All you can see on the surface are a few faint whisps curling into the morning sun. Look closer and you see deposits around the vent, foul-looking yellow and brown: a message from the inside of our beautiful planet.

Before 1944 it used to have minor eruptions every 20-odd years, but now it's blocked its own vent. It could erupt from the side, which has happened before. With all that gas and magma building up, pyroclastic flows are likely, travelling at up to 100 miles an hour at 600 degrees celsius. Or it could simply blow its top off. Last time that happened on any scale was the Indonesian Tambora in 1815. It was heard up to 1,000 miles away. Naples is hardly 1,000 miles from London, but in Indonesia the sound would have travelled across the sea: travelling across land, and the Alps, would probably reduce the bang. In 1816 there was no summer. The temperature hardly got above freezing.

But the real threat might not be Vesuvio but the Campi Flegrei ('flaming fields') caldera, a 'supervolcano' a few kilometers west of Naples. The Vesuvio vent is 600 metres across. The Campi Flegrei caldera is 13 kilometers across. Much of it lies under the bay of Naples. The earth goes up and down, there are vents and frequent tremors. Between 1968 and 1972 it rose more than 1.2 metres, and in the mid-80s the entire area was evacuated, but there was no eruption. The earth started to subside. Over the past eight years it's been rising again. Scientists have been trying for years to get the consent of the Naples authorities to drill down into it to find out what is going on, but there has been concern that drilling into it could precipitate an eruption. Fears seem to have been put to rest, and I believe drilling is beginning. Campi Flegrei was regarded by the Romans as the mouth of hell.

The effects of a major eruption in Europe would put any damage to the economy by bankers, speculators, the last government (whichever one it was), in the shade, in some very deep shade indeed, not to mention under the covering of a thick blanket of ash. The loss of life could be horrendous. In the Naples area there are plans for the emergency evacuation of some 300,000 people, but 4.5 million people live in that area. The chaos of 3 or 4 million people fighting to escape. & the likely damage seems to be calculated on prevailing wind direction, so check which way the wind's blowing before you visit. I certainly wouldn't want to live in the area. I've been in a few minor tremors and I wouldn't want to feel the ground shaking under my feet in Pompeii.

...a huge hole in the ground:
yes, those are trees on the
scree slope inside.