That ash cloud….

One of the daftest questions asked by reporters and journalists over the last few days is ‘are we going to get more of this ash in the future?’ It’s a bit like asking if there are going to be any more earthquakes in those parts of the world known to have had recent earthquakes (well, I’m sure you know what I mean). The short answer to their question is yes. The long answer is that Iceland is on the geologically active mid-Atlantic Ridge, where volcanic eruptions have been commonplace since everything on this side of the Atlantic split from everything on that side of the Atlantic at least 200 million years ago. So, it’s time we got used to it.
<<<If you don’t know what an ash cloud looks like, here’s one they made earlier (2010)

What has changed so much recently is the weather, and the way the ash clouds move and disperse. The likelihood is that many – if not all – of these climate changes are our own fault anyway. And, because aircraft contribute to the pollution of our skies, we shouldn’t grumble too much when they are grounded.

As for the timing of eruptions, it’s rather like predicting earthquakes: the further we are from the last, the closer we are to the next.

More here.

The explosives, the Garda and the cows

After hinting at it a few days ago, I thought I’d better write about this before I forget. Ireland’s Electricity Supply Board (ESB), wanted to put the new Moneypoint Power Station into the hillside to make it less obtrusive (did they succeed? I think the chimneys may give it away). To do this the contractors needed to excavate a massive amount of rock. They also needed nice clean-cut sides to the excavation (it was to be like a quarry), and to get those they had to do pre-split blasting, a line of deep drillholes charged with exactly the right amount of a certain kind of explosive, designed to crack the rock suddenly rather than produce tons of gas. The explosives arrived with an impressive escort of armed Irish police (it was the early 1980s). There were about 100 holes, and the Garda stood around for about four hours until all the explosive was in the ground. The stuff that arrived wasn’t the kind of explosive I’d recommended, but after all the hassle of getting it there we had little choice but to go ahead.

We retired to a safe distance (as it used to say on fireworks), the shotfirer carrying his blasting machine and trailing a cable. Safe distance for us meant over a small hill behind the site, as far as we could go before we were stopped by a barbed wire fence. The shotfirer sounded his airhorn, wound the handle on his box and pressed the button. There was a roar and the sky filled with clods of earth, chunks of rock and pieces of turf as all the energy seemed to go skywards rather than into the ground. It shouldn’t have done that, and it looked rather like the photos you see of volcanoes erupting in Iceland, with all the smoke and debris but without the molten lava. Our estimate of how far away to stand was about right, as the largest of the rocks and clods landed some way off. What we hadn’t allowed for was the effect the explosion would have on the herd of cows grazing in the same field, around the hill but safety away from flying debris. Were they unhappy? They came around the hill the way buffalo stampede on the prairie, about fifty of them all heading our way. The barbed wire fence no longer seemed such an impediment to us. It’s amazing how quickly you can move and how high you can vault if you really try.

I learned later that while they were charging the holes with explosives they found there was going to be a lot left over. They couldn’t return it to Dublin because they would need the police escort and also the armoured van, and that had driven away. No brownie points for guessing where they put all the surplus explosive – down the holes.

Icelandic Saga

‘Penguins are at the zoo,’ the FYO said. ‘It’s where they come from.’ ‘They have some there,’ I told him, ‘but they come from a place at the bottom of the world where there is lots of ice and snow. It’s called the South Pole.’ (I thought Antarctica was a bit of a mouthful). ‘And polar bears.’ ‘Polar bears are at the North Pole. That’s at the top of the world. They have polar bears in other places too, countries called Canada and Greenland.’ ‘And in the zoo.’ ‘There’s a place called Iceland that has a lot of ice and snow, but I don’t think they have polar bears there.’ ‘I know. My other Granny has been there.’ ‘I didn’t know that. Did she go on a ship?’ ‘No, she went in her car with me. We bought a lot of food.’