> If the left side lowers with a shift then that shift MUST be localized to the area around the fault. Because if it wasn't then that means there's an elevation change across the board for everything to the left of the fault. You see how that doesn't make sense

Yo heard of fluid dynamics? Good luck localizing this;) maybe you can build a wall or something real quick

Obviously it is all technically waves. Even if EVERYTHING to the left lowered we would be talking about waves caused by it. But it don't need to be all lowered because waves propagate. And point is these particular waves, tsunami are not the waves you think about because you saw some on the beach. It's an ocean rising for a while. Watch some vids to get a vibe for it.