Hi Donald - Here is a reference for the degrees affected in FFA:
far field aftershock - quake triggering degrees from mainshock.

0-5 degrees: Regional triggering- Up to 5 degrees west of the mainshock
epicenter,
9-10 degrees:
17-19 degrees:
34-36 degrees:
43-45 degrees:
59-61 degrees:
71-73 degrees:
103-107 degrees***:
142-146 degrees:
176-180 degrees:

*** Highest possibility

I don't know the answer about the energy repeatedly showing on seismographs.

Canie