Actually, before this thread I did not know there were more M7s in the northern hemisphere than southern. It is only when Roger made his list that there was a strong effect shown, so I then came up with a likely reason why this makes sense (although I did not pull out an Atlas and measure subduction and collision plate boundaries). As for earthquakes having a strike...depends on what you are talking about, but, yes, the faults on which earthquakes occur have strikes, and the nodal planes determined with focal mechanisms have strikes also. For larger quakes, you can generally determine which nodal plane (of 2 perpendicular planes) is the correct one. All a strike is is the azimuth (0 to 360, or really 0 to 180) of a horizontal line drawn on the fault surface.
Chris