October 11, 2012 - 1,328 Years of Japanese Earthquakes, greater than or equal to 7.0 Magnitude: I searched the NOAA (National Oceanographic and Atmospheric Administration) database for earthquakes greater than or equal to (>=) 7.0 magnitude, from 2,150 B.C. to 2012 A.D. (4,162 years). I found 180 quakes fitting the input criteria and graphed the results, in terms of magnitude (above). The red line is an exponential trend line.
The first earthquake recorded occurred on November 29, 684 and was an 8.4 magnitude event. The Japanese kept very good records of earthquakes for thousands of years, although no tremors were shown in the NOAA database prior to 684 A.D.
What surprised me was the uneven distribution of magnitudes. I would think that the highest quantity would be 7.0 and then fall off in a nice smooth line, as the magnitudes increased. This is clearly not the case. For example, there were only seven 7.2 magnitude quakes but 7.4 and 7.5 spike at 19 and 21 earthquakes respectively. Spikes can also be seen at 7.9 magnitude and 8.4. Then we have zero at 8.5, 8.8 and 8.9. Why this is I do not know.
The Master of Disaster
Thank you! I hope you can accurately predict future earthquakes for Japan. It would be very valuable for them and human life.
So do I. This is a tanting task as it has been the dream of scientists for hundreds of years, and humans for thousands. I’ll keep you posted on progress.
yours,
Bill
This is great information. By any chance, did you also graph the occurrence over time of earthquakes for each magnitude range? Or would that even make sense? Not sure.. =X
Yes I did graph magnitudes by year, power and strength ratings and other data. Since each year has many bars, in terms of magnitdue range,the graphs are very wide. They display nicely in my spread sheet but don’t show-up well here. Perhaps I could do a year or two at a time. Bottom line is each year is unique, i.e., one year will have four weak EQs, then one year will have the whole spectrum of weak to mega-quake (2011 et. al. where like that).
yours,
Bill Foster
Incredibly, I had just finished wandering over your blog when an 8.7 to 8.9 quake blasted off Indonesia. Scary stuff again… T___T