Wednesday 25 June 2008

Are there lessons from the Sarin Gas attack?

Very low probability, high impact risks are difficult to identify, unless like the New Madrid fault they have been closely researched and some idea of their impact and probability has been estimated. Lloyd's, I was once told, consider the New Madrid Fault to be the greatest risk on their books and the probability of a 8.0 strength earthquake in that area occuring in the next 50 years is put at between 7 and 10% , as stated in the June 23rd 2005 issue of the magazine, Nature.

If it was to occur it might be trigger a number of similar quakes. In 1812 there were 4 earthquakes in2 months ranging from 7-8 on the Richter scale caused by the New Madrid fault which runs from just south of Indianapolis down to Memphis.

My most unlikely high impact, low probability event was the 1995 Sarin Gas attack when I was living in Tokyo and one of the Sarin canisters passed on a train within 100 meters of my apartment. No one in my family was affected, not even my brother visiting from England who with two other professors from Sheffield University was wandering around Kasumigaseki, the Whitehall area of Tokyo and main target for the attack , wondering why there were so few people! However 12 people died and several hundred were injured.

In reviewing what I might have done differently I can see no lessons to be learned for me as an individual, which is one of the problems with this type of random high impact event. The Tokyo authorities learnt some salutary lessons regarding the readiness of their hospitals to deal with an emergency and the police learnt that they should act more forcefully when there is evidence of terrorist activity ( there had been a similar Sarin attack seven months earlier and 7 people had died) . The New Madrid earthquake , being of higher probability will find the US Mid West better prepared than Tokyo that day in March 1995.

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