5% within a week is a very high set of odds for such rare events. Or to look at it from the other more relevant direction 70% of magnitude 7 or larger quakes ha

5% within a week is a very high set of odds for such rare events. Or to look at it from the other more relevant direction 70% of magnitude 7 or larger quakes have detected foreshocks... https://en.wikipedia.org/wiki/Foreshock https://en.wikipedia.org/wiki/Foreshock