Earthquake & tsunami hits Japan

[The Camel]

Dan, I heard on the news that the Japanese earthquake was 8,000 times stronger than the Christchurch quake.

I've looked in vein for a website that can give me a laymans description of how this can be the case.

Got any links that can enlighten me?

[tikay]

Dan, I heard on the news that the Japanese earthquake was 8,000 times stronger than the Christchurch quake.

I've looked in vein for a website that can give me a laymans description of how this can be the case.

Got any links that can enlighten me?

This may help, Keith.

It lists the recent New Zealand quake at 7.1, in the Table near the foot of the page.

http://en.wikipedia.org/wiki/Richter_magnitude_scale

[tikay]

http://www.bbc.co.uk/news/world-asia-pacific-12735023

[Woodsey]

Dan, I heard on the news that the Japanese earthquake was 8,000 times stronger than the Christchurch quake.

I've looked in vein for a website that can give me a laymans description of how this can be the case.

Got any links that can enlighten me?

Also epicentre of the Christchurch one was right under the city, which is the main reason there was as much damage as there was. They were very, very unlucky.

[titaniumbean]

Dan, I heard on the news that the Japanese earthquake was 8,000 times stronger than the Christchurch quake.

I've looked in vein for a website that can give me a laymans description of how this can be the case.

Got any links that can enlighten me?

It's a logarithmic scale.

[George2Loose]

Excuse me for being thick but if there is a radiation leak how far does it spread and what are the effects?

[kinboshi]

Excuse me for being thick but if there is a radiation leak how far does it spread and what are the effects?

That's a difficult one to answer, there are so many variables.

This might help :

http://www.newscientist.com/blogs/shortsharpscience/2011/03/japan-megaquake-update.html

From what I remember,  strontium-90 is a dangerous isotope.  It emits beta radiation that if I'm right doesn't penetrate the skin. But if it gets into the food chain, especially milk, it mimicks calcium chemically and if digested can then do damage from within,  causing leukaemia and other cancers.  Strontium is one of the byproducts of fission, and radioactive caesium and iodine are mentioned in that article as others.

If the core goes into a meltdown and there's an explosion that disperses this over a wide area that can affect local populations a lot.  This is like a dirty bomb,  and I think is what basically happened at Chernobyl.  Apparently, the chances of this happening in Japan currently are pretty much zero.

I think with the evacuation zone and other precautions they have implemented,  the immediate dangers are restricted to those working on the plants, and the long term use of the land in close proximity.  Outside that I believe the risk to anyone else is negligible.

That's based on a-level physics and what I have read since then,  so could well be inaccurate.

[neeko]

Average radiation exposure for a person is 3.4mSv per year.  (1 mSv from medicine)  (this is a milli - sievert)
standard x-ray is 0.02mSv (chest x-ray = 0.06mSv)
CT scan 20 mSv
Regulations limit workers in radioactive environments to 50 mSv per year, Aircrew are limited to 20mSv per year.
Radon in Cormwall & Aberdeen can be up to 10 mSv per year. Ramsar in Iran has seen up to 260 mSv per year due to background radiation.
A 10 hour flight is about 0.05 mSv (hence one transatlantic flight is about equal to a chest x-ray)

I am not exactly sure what an mSv is but it appears to be in standard way of measuring these things. (there is also use mrem which is 100 mrem = 1mSv) I am now looking for a source that explains the no's are in Japan.

Sunday readings where 1.5mSv per hour, 0.75msv ph at 2am Monday and 0.02mSv ph later on Monday. So now 3 hours wandering in circles around the plant is equal to about a weekend in Aberdeen.

[rex008]

It emits beta radiation that if I'm right doesn't penetrate the skin.

You're thinking of alpha radiation, but I'm not pedantic. Oh, wait.
Alpha - big (basically a helium nucleus), heavy, lots of damage, can be stopped with a sheet of paper
Beta - light (high-energy electrons), not so much damage, few mm of metal
Gamma - like high energy xrays, need a lot to do damage, few feet of lead

As long as reactor containment doesn't fail (very very very unlikely at this point), the worst that can happen is that some active steam (ie mildly radioactive) is released as they release pressure. If the fuel rods are exposed at this point, this could contain some radioactive isotopes of Caesium and Iodine. Former not too bad, animals can't absorb it, latter can be bad as humans absorb it in trace quantities from food and it accumulates in the Thyroid gland. Hence the iodine tablets being passed around - if people have enough washing around, any of the radioactive version just gets pissed straight out. As long as the wind direction is out to sea (as it was last I heard) anything blown out will eventually come down as rain into the ocean, where it becomes basically harmless.

[kinboshi]

Yeah,  alpha particles don't penetrate skin - it's all coming back now.

Strontium is still a threat if it gets into the food chain, but I'm sure it's a beta emitter. Probably wrong there as well.

[kinboshi]

http://www.slate.com/id/2288212/

Nuclear overreactors - wish I'd thought of that.

[outragous76]

not looking good at reactor 2

[rex008]

LOL at the BBC Environment correspondent getting quoted on New Scientist - "This opens the possibility of a serious meltdown - where molten, highly radioactive reactor core falls through the floor of the containment vessel and into the ground underneath."

Errr, no, Richard Black, that's just sensationalist nonsense. Even if the core melted, all that would happen is that it will be trickier to clean the mess up later. Melt-through didn't happen at 3 Mile Island, and that was an older design. Very much designed for, even in a 40 year old reactor.

Another hydrogen explosion (reactor 2) isn't exactly brilliant news, but it shouldn't be a massive cause for concern either. Neither of the first two breached the reactor containment, and initial reports is that the 3rd one was smaller than the 2nd one.

[mondatoo]

First of all I'll say that although I don't know him well, I think Guy is a decent guy

But, quite obviously, due to your previous differences with tikay you decided to attack him over his comments due to your previous issues even though I'm pretty sure you knew there wasn't any malice or wrong doing by his comments. I'd go as far as to say if Cos/Vinny/Me or whoever had said it you'd probably have ignored it or agreed with it. If I'm wrong then I apologise but I'm 99% certain I'm not and if I'm right then I think it's pretty terrible that you would use a situation like this just to have a go at someone you don't like. I guess it's not possible for me to post this without it effecting our friendship but it's what I think so there we go.

I also totally disagree that Alex was hounded after his comments. I hope he continues to post on blonde but I don't think anyone was out of order towards him. I remember making a similar rant myself a while ago so I certainly wasn't judging but it isn't right to tell people how they should react to worldwide disasters happening.

[Robert HM]

Going to just sit back and wait for all the doomsayers and spin doctors to have their say then see what's showing on the Geiger counter in a few days/weeks time.