Is that why you did it?
This article speaks about the impact of a single asteroid.
The flood was the result of multiple impacts.
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Effects of an Asteroid Impact on Earth
Tsunami
The oceans cover about 75% of the Earth's surface, so it is likely the asteroid will hit an ocean. The amount of water in the ocean is nowhere near large enough to "cushion" the asteroid. The asteroid will push the water aside and hit the ocean floor to create a large crater. The water pushed aside will form a huge tidal wave, a tsunami. The tidal wave height in meters =10.9 × (distance from impact in kilometers)-0.717 × (energy of impact in megatons TNT)0.495. What this means is that a 10-km asteroid hitting any deep point in the Pacific (the largest ocean) produces a megatsunami along the entire Pacific Rim.
Some values for the height of the tsunami at different distances from the impact site are given in the following table. The heights are given for the two typical asteroids, a 10-kilometer and a 1-kilometer asteroid.
Distance (in km) | 10 km asteroid | 1 km asteroid |
300 | 1.3 km | 42 m |
1000 | 540 m | 18 m |
3000 | 250 m | 8 m |
10000 | 100 m | 3 m |
The steam blasts from the water at the crater site rushing back over the hot crater floor will also produce tsunamis following the initial impact tsunami and crustal shifting as a result of the initial impact would produce other tsunamis---a complex train of tsunamis would be created from the initial impact (something not usually shown in disaster movies).
Notice that there is a complex train of tsunamis that are created from each impact.
Each tsunami in the train would hit the land from different directions and with different force, making most of your questions irrelevant.
You are also assuming that none of the animals are buried on land and all of them are dragged out to sea and buried.