Showing posts with label Fukushima. Show all posts
Showing posts with label Fukushima. Show all posts

Mar 16, 2011

Fukushima Risk Management

With all due respect for the Japanese risk managers, engineers and the Japanese people in general: The latest 2011 M=8.9 Earthquake in Japan made clear that the current Risk Models, as well as Risk Management itself, have tragically failed.

Shortcomings in headlines:
  • Underestimation of the probability of a M=8.9 (M>8) event
  • Risk Modeling mainly focused on 'direct' earthquake effects
  • Underestimation of cumulative correlated devastating effects that occurred as a consequence of a combination of Earthquakes, Tsunamis, Nuclear Disasters and Physical Concentration (4 reactors in a row!).

It's true, the worldwide annual frequency of a serious earthquake with a magnitude of 8 or more (M>8) seems small....

Yet - no matter how low the probability- the consequences (loss) is unacceptable if the damage in case of an event (like an earthquake M>8) is not manageable, exceeds a country's financial recuperation power, or devastates thousands of lives...

End of Time?
Lots of worrywarts think the end of time has come, as severe earthquakes are increasing.

Simple statistics show that this is not (yet ?) the case:

The expected average Magnitude value of all earthquakes with M>=7 over the period 1950-2011 (March) is Ma=7.6 with a standard deviation of SD= 0.4. The average value of the last 10 years turns out Ma=7.4 with the same SD (0.4).

Nevertheless, when we examine the graphic more closely, there seems a light (significant?) increase in large magnitude earthquakes in recent decades.....

Back to the year 0
For what it's worth, the average magnitude for M>=7 earthquakes over a longer period from 0 to 2011 (March) , turns out in line with Ma=7.6 and a SD=0.44. Or in graphics:

History Earthquakes in GoogeMaps
Finally, take a look at the history of all earthquakes with a magnitude of 7 or higher on GoogleMaps... (take look at your country!)

Earthquakes, Magnitude> 7, years 0-2011 weergeven op een grotere kaart

Let's hope and pray for the Japanese people that that the brave engineers who are fighting the current meltdown at Fukushima will succeed and survive.....

Related links
- Spreadsheet (Excel) Earthquakes 0-2011 (March), M>=7
- Crash Course Earthquake calculation by Professor Nicholas Pinter
- Effect of Seismic Risk Measures on Japanese Housing Prices
- Earthquake Software
- Download Earthquake data from USGS
- Earthquake Safety of Nuclear Power Plants
- PPT:Japan’s Nuclear Energy Program(2003-2004)
- Design criteria Japanes Nuclear Plants  
- Prediction of ground motion
- Seismic Risk Evaluation (2004)
- Earthquake Facts 
- Earthquake FAQS 
- GeoBatch: Earthquakes (history M>=7)
- GoogleMaps: Earthquakes (history M>=7)