Brother-in-law remarked "the idea that the Moon plays an active roll in earthquakes and in inching plate tectonic along has been around for many decades. but he did caveat his answer by saying his use of seismology was more alied to continental shelf slumping. Basically the undersea effects of earth tremours on accumulated mud escarpments. They also cause tsunamis. Maybe like the one in the North Sea 8,200 year ago