Synchrony! (by alaric)

Our week goes like this.

Monday morning, Sarah gets on a train to London.

Wednesday evening, at 8:30pm, I get on a train to London (Jean is with her grandfather for this bit). Then at 10:15pm Sarah gets on a train back from London, the same time as my train gets in. She gets home at about midnight, then on Saturday, I come home and we get the weekend together before she goes off again next Monday morning. This is not a very pleasant state of affairs - we're a close couple, and we miss each other keenly.

Anyway, this evening, my train into Paddington was a bit early - so I rang her as my train was pulling in at 10:09. She was in coach D of the train on platform 2, waiting for it to go; my train came in on platform 3, and I was in coach E. Platforms 2 and 3 are opposite sides of the same physical platform. So I got out, crossed the platform, walked one carriage down, and there was Sarah! She came to the door of the train, and we had an unexpected five minutes together!

Lava Domes, Fracturing and Earthquakes (by sarah)

Last Tuesday I went to the Meet the Post Doc's semaniar at UCL there were two speakers the first one was Rosie Smith with Evidence for Seismogenic fracture of Erupting Silicic magma. This was interesting becuase it was looking at the fractures that occure like in the mouth of volcanos where the magma (hot rock) is pushing upwards. This means that the rocks are hotter than normal rocks that are being deformed by say mountian building events and so the fualts break and fracture and then some of them basically anneal shut again - the fracture heals its self or the rock sort of glues itself back together again.

Again these faults and their behaviours will affect the volcano-tectic earthquakes. It is also interesting to me from a structures point of view and the effects all this fracture and annealing will have on say the minerallogy and the structural integrity of the resulting rock.

However the bit that really intrested me was her talking about the apparatus she uses to simulate what is going on - they put the rocks in machines that squash them and heat them and there are obviously alot of constraints and alot of issues as to weather the sample has been treated to get rid of water and all the rest of it.

I like these types of machines and would love to use them - they can also test the aucostics of the sample so I assume they can basically hear the fractures occuring and then propergating through their samples. However you do not seem to be able to control all three axis of stress even though it is called a Tri-axial deformation apparatus - there is also an issue with thermal gradants through the samples if you are say heating it from just the bottom etc.... they are designing new equipement which sound fun too 🙂

Earthquakes and their Recurrance times (by sarah)

Last Monday I had a lecture on Fualting and Earthquake mechanics with Gerald Roberts - I'm not going to say I enjoyed this lecture becuase to be honest I found it mostly depressing.

I also both agreed and disagreed with the Gerald. Basically I will not be convinced that the apparent data skew as you back through Italy is a real data skew and not just people not recording or being in the right place to record the earthquakes - until I have seen a distrabution map of the monastrys and seen some sort of formulisation of how complete each monestries records is. Then I'd want to know what rock the monstries where standing on and therefore what sort of ground motion they would be expecting for each magnitude which I feel could dangerously biased the data - ie if they are on more ridged rock and modern towns aren't (I dont know if this is the case this is a 'suppose') then they may not have recorded the right sort of level of damage and there would be an underestermate for devastating earthquakes.

Having said all of this I do actually think he is right in the main points that he is putting across and as for those bits I doubt - I want to see the evidence and not just take his word for it - the same goes for his earthquake intensity diagram I think I understood how it was made but I don't think it was explain in a way that is going to get through to the poeple who need to listern to him.

Now the bit that I found very depressing is that earthquakes are assumed in all predictive models to have 475 yr reccurance - earthquakes can be produced by movement on a fualt now the strain builds up and up until the fualt shifts. But they are assuming that this happens at a steady rate but if you just think about snapping sticks in half this doesn't seem logical. They will break with a sort of concentrated judder. If this is happening with earthquakes then it means that you would expect a cluster or group of earthquakes to happen along a fualt one after another and then have a period of no activity whilst the strain builds up again.

Now Gerald has been measured slip rate which is I would of thought one of the first things they would have looked at with earthquake prediction - I remember doing the maths behind working the slip rates during my undergraduate so why has it been ignored? Plastic deformation ie mountian building, folding etc... is generally a precursor to the breaking of the rocks that is the fualting and thus the earthquake inducement and you measure this in strain rates which shows that for the middle of the 'crumple' zone or mountian ridge like the apanines in Italy the rate of deformation (how fast its folding up) is faster than that at the edges. So surely this means that the middle will have more earthquakes, larger and closer together.

But this is not mirrored exactly in the earthquake hazard maps produced currently as they assume this 475 yr reoccurance. This is for everywhere on the planet but they will be subject to different forces - why on earth did they get this sort of age from anyway?

Now his work shows that some fualts have longer re-occurence ages than the writen records we have - now Italy had the Romans so they have 3000yrs of records and they will still miss things - Gerald pointed this out himself. If you preject what he is saying to his risk maps then what you have is away of telling if a fault has shifted all its going to for this lot of earthquakes - this is where this become counter intuitive to poeple who haven't been looking at it in detial - areas that haven't had earthquakes for about 400 yrs are safe for thousands or at least hundreds of years rather than being about to blow (which the used maps suggest) and faults that shifted within the last century is going to go again anytime soon.

Now he showed us fualts that are behind where they should be - great you can warn those areas but then showed on the same map that there are fualts that are ahead for there earthquake quota so should be fine for ages.

This last point concerned me - if this is to be a useful tool it needs not to have faults that are ahead of themselves in the number of earthquakes they have had - the number you;ve predicted they should have had in that period of time - though over all the earthquake is expected as while the zone is active there will be strain and then slip but if there where unexpected earthquakes there then there will be when you actually project the technique into the future.

So this means you can say this area is going to have an earthquake soon but no where can actually be ruled out - now you could argue that they live in a tectonically active country they need to expect earthquakes and that is great but where should they prioritize their money for building reinforncement and the such like. Gerald thinks they should do all of it all at once but from a government perspective I doubt this will look feasible and would infact look unreasonable and there is no point in ramming facts about affects on economy of such big disastors as they are going to be getting that sort of statement from everyone about everything.

Yes I feel that as many of the buildings should be a safe as possible starting with the obvious infastructure buildings - anything new should be built properlly to begin with. Again this is heavily affected by the ground the buildings are on.

This was the bit that always makes me so depressed - he said that in Italy about 3 yrs ago there was a small mag 5 earthquake that hit a town and the only building that collapsed was the school, during the day killing about 50 kids - this sort of thing hurts me in physical scense. I don't know if it is becuase I was brought up with the nightmare shadow of the result of Aberfan where a slag heap berried a school in Wales - this happened to be where half my family where from (they were from Merthyr Tydfil to be precise though my nan was from somewhere even smaller). It was talked about with heart broken whispers when I was a child. My second cousin was involved with the rescue attempt.

I always get the guilty feeling that all this disastor management stuff or climate change stuff should be what I use my geology for but I would not be good at it - I would be doing it out of obligation and not passion. I feel I would be better off and more lickely to find something that will actually help people by researching something I am interested in and just talking to other geologist and scientists about their fields. The earthquake stuff is still depressing me though.

Linear Dunes (by sarah)

Last Wednesday I had an interesting lecture on the Linear dunes of the Namibia from Charlie Bristow he specialises in modern sedimentary environments. I have always liked sand dunes I really enjoyed all the Applied Sedimentology course I did at Imperial except the petroleum bits and even quiet alot of that I found interesting.

The premise people had been working on was that these huge dunes where left over from the last glacial maxium but this turns out not to be so. There is cool dating techniques you can use on sand that has been sitting in the dark - you get like an exposure date for the last time it saw sunlight as the sunlight 'bleaches' the sand grains and sets the exposure age to zero.

I remembered from before that there where three types of motion on the sand dunes - there are little sort of parasitic dunes moving across the huge great big stonking dunes for a start. It is/was thought that these types of dunes do not appear in the geological record so they where of interests becuase of that but in cutting into the dunes it is now thought that they might look simialar to other types of dunes - dune morphology and how they look inside due to migration (the wind blowing them sideways or back to front or whatever) is actually a bit of a geometric nightmare to get your head around especially when you start looking at how a paloe (old turned into rock) dune bed can be exposed - it could be tilted, cut at a strange angle and all sorts.

Anyway the dunes are younger and would appear to be able to tell us about climate changes that may have occured in the area - this includes looking for 'fossilise' hirax poo but these are rare. There are also fulgurites which are the formation you get when lightning hits sandy substrates which supports the idea of climate change which would have produced vegitation ie it got wetter - it started to rain and plants grew their root sort of stoped the dune sand from being blown about.

I suggested they look for root material which is apparently on the cards.

Prince’s Trust (by sarah)

Last Friday I went to a meeting with two mentors from the Prince's Trust to talk to them about my business plans. I have been making websites and setting up blogs for people for a while now and I thought I should move forward with this and turn it into a proper business.

So I spent Thursday last week writing out my business plan which was a good thing to do anyway and made me realise how far ahead with things I actually am. The Prince's Trust was something that Flo initially told me about back before the pregnancy and I had been toying with the idea of starting a craft business but I got cuaght up a) being ill and b) blogging about the craft on Salaric Crafts but the blogging led to writing and that led to websites for people I met through writing and wham - here I am.

I think I have a niche and am excited though in some ways I wish it had all started to kick off last year (which it couldn't due to the flood) or that they had waited just a bit longer to get around to contacting me so that I wasn't in the middle of having to write essays on the formation of the moon and the such like.

I don't know if I can't get the financial help from them but even if I can't I want to have the business tutoring as I feel that will be most helpful.

The Prince's Trust help poeple under 30 set up their business's which is cool and hopefully will help me sort our lives out. Unfortunatly I am asking for just over the amount that you get without having to 'Go to Panel' . I need servers and I need to have them in a data centre so I am asking £2000 which is basically the servers etc.... my hardware costs :'( The panel is apparently something that looks like Dragons Den but they say they are friendlier - well they couldn't be less friendly could they!

They got excited about my 'mind map' that I had drawn in Jean's feltips for added colour in a typically me way - I thought it was a flow diagram and thought mind maps where what Carinia was calling the things she was drawing for her PhD stuff. So now I am wondering if mind maps is a sort of catch all for things I term: Brain storming, flow diagrams and spider diagrams.

I probably should investigate this at some point.

One of the things that I am having to do at the moment is heavily prioritize what I spend my time on and sadly this means that for the last two months I have done no art or craft but then this is my ultra busy term.

I have a list of homework from the Prince's Trust as well as from college but I am afraid playing with Jean still comes highest on my agender. She is being quiet mischevious at the moment as well - unfortunalty she has developed sciencetific method for finding out exactly what she can and can't get away with.

The funniest thing she does though is wait for me to get up from the laptop then she climbs into my seat and says, 'Can I do your work now Mummy?' and she sits just like Alaric poised to start a heavey programming session.

Well here I go again....