Piri Reis Map could point to an ice-free Antarctica in antiquity

Map of the world by Ottoman admiral Piri Reis, drawn in 1513.Only half of the original map survives and is held at the Topkapi Museum in Istanbul.The map synthesizes information from twenty maps, including one drawn by Christopher Columbus of the New World. This is a file from the Wikimedia Commons. It is in the public domain because its copyright has expired.

The oldest known map of the world was compiled by Ottoman-Turkish admiral and cartographer Piri Reis. He used 10 Arabian sources, 4 maps of India from the Portuguese, and a map of the New World made by Christopher Columbus to compile his map. The map is drawn on gazelle skin.

Only the Western third of the map has survived. It lay undisturbed in the Topkapi Sarayi Library until German theologian Gustav Adolf Deissman discovered it in 1929. According to an online Wikipedia article, Piri Reis Map: 

Amateur historian Gavin Menzies claims in his book 1421: The Year China Discovered America that the southern landmass is indeed the Antarctic coastline and was based on earlier Chinese maps. According to Menzies, Admiral Hong Bao charted the coast over 70 years before Columbus as part of a larger expedition under the famous Chinese explorer and admiral Zheng He to bring the world under China’s tribute system.

I became interested in the Piri Reis map while researching background information for my End of the World 2012 Movie. I thought that if the Piri Reis map showed the Antarctica coastline, it meant that one of the sources used in compiling the map had to have been made during the time Antarctica was free of the mile thickness of ice covering it now. If so, it would show evidence of the world undergoing previous cataclysmic events. Perhaps, a pole shift?