Not all earthquakes are created equal

Some countries cope better...

My two cents (2) about the July 2019 Southern California earthquake: recorded Richter magnitude M 7.1. Not bad huh? Pretty "high." It makes me think sadly to some of our most recent earthquakes in my country, Italy: central Apennines in 2016 and northern Apennines in 2012. The magnitudes recorded were respectively M 6.0 and M 5.9. Seen this way they would seem just a bit weaker but they did a lot of damage and deaths.... I don’t know about you, but it makes me think.

For the way Charles Richter thought the magnitude scale for earthquakes, the difference of 1 degree of magnitude is remarkable: the difference in displacement of the ground is 10 times, while the energy released with one more Richter degree is about 30 times higher (31.6 to be precise). For the particularity of the Richter scale a difference of 2 degrees results in 1000 times the energy released, of 3 degrees results in over 30000 times more energy released, at 4 degrees we are already at 1 million. So we must be careful when saying that an earthquake was "only" one degree stronger than another (a difference of 0.1 is equivalent to about 4000 tons of TNT).

In other words, the energy released with M 6.0 is equivalent to 13.7 tons of TNT, the equivalent of the Hiroshima atomic bomb; M 7.0 corresponds to 432.6 tons of TNT, or 31.6 Hiroshima bombs (31.6 times more). There are several converters online if you want to have some fun.

The point is that the 2019 California earthquake released about 30 times more energy than the more infamous recent Italian ones. In Italy they were real tragedies, a real massacre in Amatrice, in the central Apennines; in California hardly anyone was hurt. About ten tons of TNT in Italy caused a disaster; 400 in California caused little damage (1 dead and 25 injured, some fire). Not to mention Fukushima, Japan, 2011, a frightening M 9.0 equal to 32000 Hiroshima bombs or 432,6 million tons of TNT! Many damages and many dead, but mainly because it triggered a devastating Tsunami. In reality the structures resisted well to the shock, to the enormous vibrations of the ground (it seems that they have also moved the earth's axis beyond as well as some coasts of Japan!).


The California earthquake is proof that it is possible to build well, so as to limit earthquake damage and casualties. It is well known what kind of earthquakes could happen both in California and in Italy. Italy, however, is a much older country and the ancient historical centers, which bestow upon it part of its world-famous beauty, are not suited to resist earthquakes of this magnitude. In central Apennines, for example, the buildings outside the historical centers have resisted relatively well or at least have not caused victims. However, it must be said that usually many damages and victims in Italy are also due to modern constructions made without following the anti-seismic norms.

It would be necessary to secure the historical centers of our territory, starting from the highest risk areas. Can it be done? I don't know. Certainly the investments would be huge. Where to find the money? I don't know, but we should not have doubts about the value of human life. Or should we? It comes to me to think that it is more convenient to rebuild than to prevent. It is also more visible and brings more votes (if I make safe buildings and an earthquake happens, it is not news). I remember the outrageous news about cheerful phone calls among developers in the aftermath of the 2009 central Apennines earthquake (M 5.9).

Therefore it is easy to assume wrongful doings. Even more so when you consider that controversies after some Italian earthquakes have concerned the hydrocarbon wells whose activities would have triggered the earthquakes (crazy!); in 1997 some scientist were put to trial because they were not able to predict it (even worse!). It seems like a lot of noise made on purpose to cover the real problem: buildings that are not up to standard. Too simple? I'm afraid it is - the difference between us and California is in the quality of the buildings. Here people die for much less than a magnitude 7 earthquake! All the rest is just sterile polemics.