anecdotal... ~"When an inner situation is not made conscious, it appears outside as fate." Karl Jung~
Three earthquakes per week all larger than 8.5 magnitude randomly distributed across the globe, that would be abnormal. And yet not -entirely- unlikely.
Last time we run that exercise (for Chile) there was nothing abnormal.
... The Year v. Magnitude plot is interesting. First, historical earthquakes (before 1900) are all Magnitude 8.5 or stronger. Also, 5 of them earthquakes are exactly 8.5 magnitude, 4 of them before 1900. This is because historical magnitudes are estimated from accounts of the damage and not from seismograph measurements. Also, earthquakes weaker than 8.5 "didn't make history". So there is a selection bias in the old data, similar to the ones one find in astrophysics where the farther out one looks the bighter an objects needs to be to be seen. ...
...
The Year v. Magnitude plot is interesting. First, historical earthquakes (before 1900) are all Magnitude 8.5 or stronger. Also, 5 of them earthquakes are exactly 8.5 magnitude, 4 of them before 1900. This is because historical magnitudes are estimated from accounts of the damage and not from seismograph measurements. Also, earthquakes weaker than 8.5 "didn't make history". So there is a selection bias in the old data, similar to the ones one find in astrophysics where the farther out one looks the bighter an objects needs to be to be seen.
USGS: Earthquake Facts and Statistics
Frequency of Occurrence of Earthquakes Magnitude Annually 8+ 1 * 7 - 7.9 17 * 6 - 6.9 134 * 5 - 5.9 1,319 * 4 - 4.9 13,000 (estimated) 3 - 3.9 130,000 (estimated) 2 - 2.9 1,300,000 (estimated) * Based on observations since 1900.
Magnitude Annually 8+ 1 * 7 - 7.9 17 * 6 - 6.9 134 * 5 - 5.9 1,319 * 4 - 4.9 13,000 (estimated) 3 - 3.9 130,000 (estimated) 2 - 2.9 1,300,000 (estimated) * Based on observations since 1900.
