Friday 27 May 2011

Shaken and stirred

On April the 6th, 2009, there was an earthquake which killed 309 people in L'Aquila, Italy. Thousands of people were made homeless and a national disaster was declared. Two years later, though, there are still some after-effects being felt. Legal, not geological.

Increased seismic activity in the area had prompted the setting up of a committee to assess the threat posed. The group felt that while the main fault was clearly active, the consistent series of smaller movements they had experienced was ensuring energy was being released and that, consequently, the chances of a larger scale quake were lessened. Their findings were summarised and communicated to the public by a non-geologist from the group, a government official from the Civil Protection Agency. He felt the geologists had been relatively positive and gave the opinion that the threat of a major earthquake wasn't too serious.

And then...

Currently, six seismologists from that committee are to face trial for manslaughter alongside the government official. Apparently they are being prosecuted because the report offered 'incomplete, imprecise and contradictory public information.' For being wrong. Because they had falsely assured the public. Firstly are we to assume 'the public' will have taken this report as a cast-iron promise nothing bad would happen? I doubt that. Let's also leave aside the fact that some of the geologists feel their discussions had been misrepresented  - that may be legal positioning in advance of the blame game ahead. Predicting earthquakes - while aided now by far more technology and understanding than ever before - is still a very, very difficult job. Even coming reasonably close to accuracy is mightily impressive, given the number of factors at play. So can these guys be blamed? Be given ten year prison sentences for not being able to predict natural phenomena? To me, that seems far beyond harsh. It's looking for someone to blame.

The logistical and financial nightmare of evacuating a city means it rarely happens. Lost trade, the risk of crime, moving the elderly and sick, etc, etc. There have been occasions when seismologists have been advised to play down potential risks to avoid widespread panic, too. Then where would the blame lie? Who would carry the can? If this prosecution goes ahead, surely there will be far fewer seismologists willing to offer risk assessment short of advising everyone to run at the first sign of a tremor. You could employ anyone to wave their arms about and scream, you don't need a seismologist for that. This is stupid and may have serious repercussions.

Thursday 26 May 2011

Shapes

Today I was supposed to leave a little early so Kate could get to her book group. I got the grille up, the sign in and half of the storm doors closed. As usual in these situations, someone came in.

'Hi, the museum sent me down here, because they were too busy.'
'Oh, right. Okay.'
'Here, look.' He pulls a stone from his pocket and hands it to me.
'Look - here - a face. With one of those... you know. Like this.' He gestures.
'A ruff?'
'Yeah. And a big collar, look.'
'Mm.'
'And here is another face, a bit smaller, in this shape... here. You can see it better if you wet it a bit. See?.'
'Okay.'
'Look on the back. It looks like a number.'
'I don't... I can't... really see what you mean. I think it's igneous. A volcanic rock. You don't get... fossils in igneous rocks, though.'
'Do you not see what I see?'
'No. No, not really. Sorry.'
'I have another. Here, look at this.'
'Well this one looks like a piece of ironstone nodule I think.'
'Not a meteorite, you don't think?'
No. Sorry. Look, I really have to close up now. Sorry I couldn't be more helpful.'
'Ok, no problem. It's just the museum folk sent me down here. Too busy.'

Friday 20 May 2011

Star born

There are over 4,500 named minerals on Earth. There will be plenty more found and named, too, unless the latest bunch of Rapture people are right about tomorrow and things all go pear-shaped. There haven't always been this many, though. At the moment it's thought that when the planet was formed there were only around sixty minerals. Discovering a new mineral must be quite a thrill - I met a guy once who had been named as official discoverer of a few, though I can't remember the names. A couple have been found recently that date right back to the origins of the solar system. Krotite and Wassonite were both found by careful study of meteorite sections.

Krotite was found in a meteorite from North Africa and contains a substance that can only form under conditions of temperature and pressure that match the creation of our solar system 4.55-4.6 billion years ago. Further study of the mineral might help scientists understand more about how minerals originally formed from the collapsing molecular cloud during that time. As the nebula cooled particles of matter began to group together and minerals were precipitated. Those minerals that form at the highest temperatures would obviously have formed earliest, and krotite would have been amongst the first.

Wassonite was discovered in an Antarctic meteorite which had been found some 42 years ago. The crystals of the mineral were too small to be seen until recent technology - the Bond-villain-esque ion beam - allowed a proper analysis. Wassonite is titanium sulphide. And really, really tiny.

As technology develops mineralogists will be able to find more and more minerals in meteorites. Meteorites are pretty tremendous in themselves, just for being a rock that's fallen out of space, but when you think of them as some of the first solids to have formed at the formation of our solar system, they gain a little something. Respect your elders.

Tuesday 10 May 2011

Old school malware

Phone rings.

'Good afternoon, Mr Wood's Fossils.'
'Hello, can I speak to Matt Dale, please?'
'Speaking.'
'Hello Mr Dale. Are you in charge of the company's computers?'
'Um. Yes'.
'I'm calling from the Computer Maintenance Department.'
'The what? Computer Maintenance Department of what?'
'Of Microsoft. Do you use Microsoft Windows?'
'Yes.'
'We are calling because your warranty has expired, which is why we have been receiving error messages in our department.'
'Which warranty? I haven't been getting any error messages. My computer's fine. What are you talking about?'
'Your software's warranty has expired, leaving your computer open to virus infection. We have been receiving error...'
'My software's warranty. Right. Well, I haven't had any error messages, and I have anti-virus. Everything's fine. Thanks for being so worried. Got to go now. Bye.'

Hang up.

Friday 6 May 2011

Cut glass

Obsidian is a volcanic glass made when lava cools very rapidly. It happens too quickly for a distinct structure to form and when fractured, the edges can be just over a molecule thick. Which makes for a pretty sharp edge. Unsurprisingly, then, it's perhaps best known for its use in prehistoric times as a source of arrowheads, cutting blades and the like. Less well known is that obsidian is used to make surgical scalpel blades now, as they produce a narrower cut than a conventional steel blade and result in less scarring.

Most obsidian looks black at first glance, but on closer inspection it is usually translucent if thin enough and dark brown, grey or even greenish in colour. Above left is a polished piece of rainbow obsidian. Layers of tiny bubbles arranged along flow layers create a colourful iridescent effect. There are other well-known forms called mahogany, where high concentrations of iron makes a red/brown pattern throughout, and snowflake obsidian, which has clusters of white cristobalite.


Apache tears (shown right) are little blobs of obsidian found near Superior, Arizona. They are found surrounded by grey/white perlite, which is a hydrated form of obsidian. These little pebbles have a folk story of their own. In the 1870s, a group of US cavalry and volunteers set out to attack a band of Pinal Apaches, prompted by repeated cattle raids on a nearby settlement. The Apache, seventy five strong, were attacked at Big Pacacho and most of their number were killed in the initial gunfight. The remaining warriors, rather than submit to the cavalry, committed suicide, riding their horses over the cliff to their deaths. The tears of their families, on falling to the white sands surrounding the base of the cliffs, were turned to stone by the creator, Ussen, to mark the memory of the fallen Apaches.