|when you're looking for a solar activity vs Earth-quakes correlation...|
forget sun spots
forget solar flares
forget the geomagnetic index
Those things that scientists traditionally look for when trying to find pattern in the sun/earthquakes relationship aren't where you need to be looking but Ben Davidson has found a more reliable trigger mechanism for large scale earthquakes on Earth.
Sure, the sun has an eleven-year sunspot min/max cycle but one can't consistently relate this to large 8.0+ magnitude earthquakes on Earth, or where they'll strike. The real driving mechanism for the larger Earth-quakes (Davidson contests) appears to be the underlying eleven-year cycle of Solar Polar Magnetic Cycle.
Basically, the sun's magnetic pole enters a negative magnetism peak, whammo...