The Shape of Earth Itself Changes With Every Glacial Cycle

Over the last 2.5 million years, the Earth has moved through multiple interglacial cycles in a rhythm Randall describes as the planet itself breathing. Ice accumulates, ocean levels drop, and the redistribution of mass across the surface is so profound that it literally changes the shape of the geoid - the geometric form of the Earth itself. This is not a minor climatic fluctuation. It is a planetary-scale restructuring that repeats on a geological schedule.

The evidence Randall points to is still visible today. Where the great ice sheets were centered over North America - particularly around the Hudson Bay region - the land was depressed by approximately 1,500 feet under the weight of the accumulated ice. With the removal of that ice over the last 10,000 to 12,000 years, the crust has been slowly rebounding - a process that is still ongoing. The meltwater from the North American ice sheets returned predominantly to the North Atlantic Ocean, redistributing that mass back into the world's seas. Randall’s argument is that understanding this cycle is not optional background knowledge. It is the physical foundation against which every theory about ancient civilization, catastrophe, and human prehistory has to be measured.