hi
look at one more hypothesis observed in predicting major quakes

Moon is the main trigger in major quakes(let people believe that the pull is so tiny that, it can hardly move a leaf.)The differential pull induce 4 to 6 mtr of high tides in oceans
Main point (hypothesis) is like this
Maximum declination( both north and south) of Moon plays major role in quake trigger.When Moon reaches max declination and then moves back ,it creates a sort of jerk (change in momentum due to direction change).
Most of the 7+ quakes are observed on dates with maximum declinations combined either Moon at perigee or full moon/new moon
Further ,MOON MAXIMUM DECLINATION IS GENERALLY 22 DEGREES,BUT IN SOME YEARS(2004 eg) IT REACHES UP TO 27 DEGREES.

These dates when Moon reaches 27 degrees north or south, when combines with one or two more triggers can give 7+ quakes
Amit