Its funny because if you think about it, 20 miles along and 4 miles down is only a 5:1 gradient rather than anything like the sheer cliff you are envisaging. T

Its funny because if you think about it, 20 miles along and 4 miles down is only a 5:1 gradient rather than anything like the sheer cliff you are envisaging. The ocean is deep but also wide. I have a chart of the Atlantic which is about 1m square. Although the Atlantic is several miles deep and the chart is only paper, the thickness of the paper is not far off scale..