Why build a wall and pump? Just start dumping rocks at the center in the planned volume or a few % more to account for subsidence at the edges to the known angle of repose. Voila, your land mass for less. And it would be quicker - probably done by next April Fools' Day.
Why build a wall and pump? Just start dumping rocks at the center in the planned volume or a few % more to account for subsidence at the edges to the known angle of repose. Voila, your land mass for less. And it would be quicker - probably done by next April Fools' Day.