Migrations of strain or fluid movement or fluid pressure have often been proposed to explain evolution of the location of earthquakes over time. However, few places are known to have had such transients, mainly locations of hot crust like ridges and oceanic transforms.

I and many others have tried to write computer code to identify either migrations of locations or simply lineations in seismicity (aside from the obvious faults) to identify regions actively deforming, without success. It is much tougher to identify such migrations without using your eye, which loses any sense of what is and isn't significant, and can't perform in a reproducible way.

More fundamentally, we have sensitive tools to detect deformation. We're not seeing enough deformation for there to be much of a strain wave hidden underground.