it's where the friction of the crust to the core is reduced by magnetic effects (the galactic current sheet) and the crust realigns itself to a magnetic declination that matches the external field
the oceans are pushed up over onto the land in the direction of the rotation and then after that peaks it goes backwards again and washes back "slosh-back" across the other side
the safest places to be when this happens are where the motion is least intense, the "eye of the storm" which will be in the region i show on that image, everything in that central area and on the antipodes will have relatively low ocean motion but on the edges it will flood everything
this is what happened with Noah, it even describes it and there is not just noah but other accounts of this where the sea just keeps on rising and rising until everything is covered up, this is from the inertia of the water from its previous motion, compared to the new motion
once the crust magnetic alignments equalise to the new position everything starts to settle down, but in the process it takes maybe months, at first, and on top of this, there is, leading up to it, massive uptick in volcanic, seismic and storm activity, and afterwards, and at least the last time this happened, 12000 years ago, it triggered a minor glaciation known as the ice age that created the stone age, then after it started to warm up (likely caused by impactors, formed out of the material the sun blows off during this incident)
yeah, it's pretty freakin intense... The Apocalypse of Yajnavalkya has many references and recounting of descriptions of the events of this time, including stuff about "fire dragons battling in the sky" and "evil sun turning blue" and many other things like this, all of them consistent with a micronova, and the flood itself is a pole shift, it's not a flood, per se, it's a massive movement of sea water, while at the same time massive energy has hit the atmosphere triggering almost total cloud coverage and storm conditions