Finally, here is my most recently formulated conclusive summary:
It is the multiplicity of vortexes, associated with the speedy spinning small size super-massive objects, like super-massive Black Holes, which induce high amplitude spiral waves.
These are the spiral waves traveling along the space-time fabric, carrying and transferring their energy to the distant massive objects.
Once the wave runs into another super-massive object and gets into the space-time dip surrounding it (actually also oscillating), an intense wave interaction is induced causing probably a strong tsunami-like repelling effect.