Why try to find a scientific explanation for something that is expected to be taken on faith?
I believe that at some point tectonic drift occurred. Looking at the continents today, you can see how they seem to fit as if they were separated at some point.
This could easily have taken place during the flood.
Lets say the planet was far closer to flat than it is today. The flood wouldn’t have needed to be 30,000 feet deep to cover the ground. As the flood wound down, ocean valleys developed and mountains were shoved up.
I would also like to address the idea of rain. When did it start?
Was there rain in the garden, or was the moisture provided more by dew and subterranean access?
The reason I ask this, is because until the flood, man had not seen the rainbow. God is described as providing it as a covenant between Him and man, as a reminder He would not destroy the earth again by water.
Was water mostly subterranean until the flood? Was water expelled from the earth as well as the sky? Was the tectonic shift related to all of this?
I don’t know the answer. So as you state, it is a matter of faith. There are many questions we’ll have for our Savior after we are restored to Him.
Until then, may the faith be with you.
> Why try to find a scientific explanation for something that is expected to be taken on faith?
Because the concept of metaphor - and for that matter, the concept of object permanence - is too advanced for many.