Seems to me . . . that the "experts" (truly ex spurts)
insisted that nothing like a 30-40 foot virtical displacement off Sumatra could not have instantly happened, either. But it did.
And, they seem to feel that the 27 or whatever odd feet crack over 3 weeks was durn nai impossible, too. But it happened.
Now, does some bright geologist without his brain stuck on fossilized have the courage to extrapolate 27 or whatever feet over 3 weeks into say something AVERAGING similar over say 15-25 years? Seems to me the sea could engulf such in a lot less than they've projected.
It will be like any large body of water. If it finds a crack, it will rush through it to seek a position of rest. (lowest point).
As it is rushing through, it will enlarge the path. That means more, and more, and more, and it never stops until balance (equilibrium) is achieved.
Any true expert would have known that could happen. We have plenty of prior experience with major displacements. Tens of feet is not unusual for a massive event. The 1964 Alaskan earthquake had similar measured vertical displacement on land, with even higher displacement suspected on the sea floor. The 1960 Chile earthquake had somewhat less vertical displacement, but similar magnitude.
Geologists have plenty of experience with events of this size, given that it happened at all, the specific results were not out of the ordinary for an event of that size.