One minute before sea level change. Is this the sea level change where the water draws back from the shoreline, or the big crashing wave?
I think they mean right at the location of the quake.
Question — is there a big crashing wave, or is it more of a powerful surge without much height? I suspect it may be based on the local ocean floor, but if I recall correctly, the Japan tsunami that wiped out the nuclear reactor was more of an inundation than crashing wave. I defer to your expertise on the answer....