Do earthquake numbers matter?


Continuing on the theme of the supposed “increase” in earthquake activity one of the things I often come across is the nonsense graph that shows earthquakes going up and up since 1970.

Michael W. Mandeville Earthquake graph

(C)Michael W. Mandeville


This takes the data from the USGS it says. The page referred to is probably this one.

Aside from the fact that the graph is now 10 years out of date, let’s take a look at the figures. Please also bear in mind that, as the site states:

As more and more seismographs are installed in the world, more earthquakes can be and have been located. However, the number of large earthquakes (magnitude 6.0 and greater) have stayed relatively constant.

First World wide figures for 1990 to 1999

Worldwide Earthquakes 1990 to 1999

Now the earthquakes for the United States

United States 1990 - 1999

It is relatively easy to see that the USGS statement is correct. It is also relatively easy to see that the US quakes are fairly constant as fewer new seismographs were installed pro-rata than worldwide.

If we take the total of the quakes compared to the total number of 5.0+ we can see that the number of the larger quakes in that time period actually went down.

Worldwide Earthquakes 1990 to 1999

Basically the Mandeville graph presented is based on bad science and serious logic flaws.

Flawed Study, Bad Science, Outrageous Conclusion

So to the numbers

Let us look at Baja California since 01-01-2010. Since that date there have been 22,247 earthquakes from mag 1 upwards – counting up to a day ago.

For each band of earthquakes I calculated the energy released using the formula

(10^(4.8+(magnitude*1.5)))/10^12

which gives us the gigajoules of energy released.

I have bunched everything under 3.0 into one band.

  • 1.0 to 2.99 – 20,766 earthquakes released 2.5611 GJ energy
  • 3.0 to 3.99 – 1,316 earthquakes released 11.92 GJ energy
  • 4.0 to 4.99 – 153 earthquakes released 40.4201 GJ energy
  • 5.0 to 5.99 – 11 earthquakes released 80.3913 GJ energy
  • There were no 6.0
  • 7.2 – 1 earthquake released 3,981.0717 GJ energy

The ONE 7.2 was 29.42 times more powerful than all the 22,246 quakes put together.

SIZE MATTERS – numbers do not.

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About PuterMan

A retired programmer.
This entry was posted in Earthquake. Bookmark the permalink.

One Response to Do earthquake numbers matter?

  1. Rustynailer says:

    Very interesting and informative.
    Thank you.
    Russ

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