Lots! It's my opinion that prior to the flood, that area was a jungle, with big animals and palm trees. After the flood, when the world was knocked off its axis and that water layer was gone, it froze up. This is the informed opinion of many "creation scientists."
It is a fact that if we cranked up the bull dozers and pushed all the land into the sea, (they would need to be submerisbles in order to "even out everthing), we would indeed have a water world with the average depth of the ocean exceeding a mile!!!!