While the geographic South Pole is the point where the Earth's axis of rotation intersects the surface, the "southernmost" spot can be defined in different ways:

* Geographic South Pole: This is the point where all lines of longitude converge.

* South Magnetic Pole: This is the point where the Earth's magnetic field lines converge. It is constantly shifting and is not fixed like the geographic South Pole.

* Southernmost point of land: This would be a specific point on the continent of Antarctica, with the exact location changing depending on how you define "land" (e.g., includes glaciers or excludes them).

So, the answer depends on what you mean by "southernmost spot."