What do you mean by "global to some extent?" Are you claiming it was a global shallow flood that only hurt coasts? Are you saying it was only certain continents?
I just mean that damages was probably not equal everywhere depending on how far you were from what triggered the water movement and the geographic landscape.
Nothing could trigger something like that. It would take magic. Physics wouldnt allow the continents to sink below the ocean or for water to flow up onto land out of the oceans.
