Hi Don,

Sorry for the interruption.. For a given location, finding out a major quake's magnitude
is not a problem if properly applying sun shadow method. Please refer my prediction in the
message board, vide

http://www.earthwaves.org/wwwboard/messages/21881.html

and the result vide

http://www.earthwaves.org/wwwboard/messages/21896.html

If you need further accuracy in finding the magnitude, I say my apologies for the interruption.

Shan