Amit, the wording of the news article says the quakes were after a few hours, not 1 year. The were triggered by the slower seismic waves. That the seismic waves of a very large quake can trigger other quakes has been recognized by seismologists since it became obvious in 1992 aftre the Landers quake. Lowell Whiteside, who used to post here and introduced me to Earthwaves, had this sort of triggering in his 1990 Ph.D comprehensive report.

Yes, they are different plates but seismic waves from quakes cross plate boundaries.
Chris