[ForGod'sSake]

I wonder what water depth this was based on?

It appears their graphic is based on a sea level drop of ~425 feet. Late Pleistocene time period in particular. Have a looksee.

FGS

[blam]

"It took so much water to form the glaciers that the world sea level fell approximately 140 meters (425 feet). This exposed the flat continental shelves, now covered with water, as dry land. This lowering of sea level has the same effect as raising the land, which caused rivers to begin eroding deep valleys. The Lower Mississippi, Tombigbee-Alabama, and Red River systems formed deep cuts in the existing land surface. As the glaciers melted and sea levels rose again, the valleys were filled with sediment carried by meltwater-swollen rivers."

Very good, thanks. I've read that the Nile River valley must have looked like the Grand Canyon.

I got to thinking about this due to the 'under-water-city' discovered off the west coast of Cuba...it's under 2,200ft of water, too much for subsidence, IMO. I proposed that it was built on the shore of a dessicated Gulf Of Mexico that was later flooded.