The Earth has a circumference of approximately 25,000 miles. According to the Noah Fable the earth became dry again after 370 days. Therefore the tsunami speed and height can be calculated. 30,000 feet of water which rose at a rate of 725 feet per day then circled the globe in 370 days. So the giant tsunami moved at a speed of 1000 miles per hour around the earth.
That's a real wow story. Tsunamis a pittance that tall and moving much slower do horrendous damage. Noah sure was a good boat builder.
This could be a little misleading because you have
set the scene shall we say and we would have to abide by the way you propose it, shown in your quote above, directing some response to your
thought-exercise of sorts in that proposed direction. I would have probably tried the
puzzle myself, straight away, after you would have posted it but now I won't
abide to your proposed tsunami scene, If you don't mind.
Water coming from below is
not from
one individual source like one
single gargantuan tap or that there is one-only great-drain when water could easily finds it's way throught the cracks of the earth e.g. levels receding all over the place.
There would be tsunami like forces on EVERY
coastline when waters rise up. I would assume valleys below sea-level, would have similar effects like dams bursting. We know the devastation effects of heavy rain in just a few days in low-lands and large area flat-lands that are known to have monsoons.