Some Good News.

The Asian Tsunami of December 2004 was caused by an earthquake of magnitude 9.1. That created a 23 metre high wall of water that moved at around 500 miles per hour and killed upwards of 500,000 people.

The fact that the tsunami created by today's 8.9 magnitude earthquake in Japan appears to be fading away without causing any further, significant loss of life means that today has been a good day. Taiwan and Indonesia both reported a series of waves of around 0.5 metres in height at around 12:00 (GMT)* Hawaii reported another series of waves of around 0.75 metres in height at around 13:30 and the tail end of the tsunami is expected to arrive in Chile at around 02:00. However the impact that a tsunami has depends very much on the specific landscape and tidal currents were it makes landfall. They can also appear as a series of waves often hours apart. Therefore the advice to anyone in a Tsunami warning area is still to keep away from coastal areas and follow the instructions being given out by local TV and radio stations and the men in uniform shouting at you in the street.

I have yet to here how the multitude of small Pacific Island states have coped with the tsunami. A lot of these islands are dirt poor and very close to sea level. Therefore it is probably worth keeping some of the international relief effort, especially helicopters and flood teams, in reserve.

Meanwhile in Japan they've had a problem with one of their nuclear power stations. In Japanese nuclear power plants as soon as the central computer detects seismic activity it automatically shuts down the nuclear reactor. The problem though is that nuclear material doesn't have an off switch. So when you switch off a nuclear reactor you need to start pumping coolant across it in order to cool the nuclear material in order to avoid a fire and a Chernobyl style incident. In the Fukushima-Daiichi power station the diesel generator that was meant to power the coolant pump failed to switch on when the computer told it too so they sent down a man with a hammer who declared the generator to be broken. In the several hours it took to get the coolant pump working some of the nuclear material appears to have overheated, melted and leaked out somewhere in a Three Mile Island style incident. Fortunately nuclear safety has improved dramatically since Three Mile Island so in this case the nuclear material only appears to have leaked into a lead lined, concrete chamber that was designed for just that purpose. Although I believe this account of the event to be accurate the risk has been greatly reduced by the Japanese taking every possible precaution including evacuating people from 3km around the site. Since about 1945 the Japanese have become really good at dealing with nuclear incidents although it's been such a long day I can't remember why.

It is now just approaching dawn in Japan and at first light the government can begin a full impact assessment. It is still too early and tasteless to speculate on the number of people killed but I think Japan should be prepared for a death toll of 200+.




*As the incident crossed the international date line, unless otherwise stated, I will be using GMT for the time and the western date as it begins in Japan. I sure that somewhere there is already a very complicated argument breaking out about the eastern and western measure of earthquake intensity.