Hi EQF. I don’t see it supporting anything one way or the other. We don’t know what the frequency of occurrences of M>8.0 quakes were 10,000 years ago. For all we know there could have been periods of a100 years in which there were no quakes above M>8.0. Then again there could have been a period in which there were 2 or more M>8.0 every year.

The NOAA quake catalog goes from 648 to 1994 for a total of 246 quakes. You can find periods of 100+ years which there were no quakes of M>8.0 and larger. Does this mean that there weren’t any? No. Most likely they occurred where no one was living at so therefore no knew there was a major quake. If there were people there they left no written record of one.

A 30-year database is just to small to draw any conclusion about why more quakes occurred in the 90s as opposed to the 70s and 80s. Take Care…Don in creepy town