|Fashionably late to the New Years Eve party|
The ice cap is constantly shifting and carries the base away from the South Pole. Every few decades they build a new station (environmental wear and tear is pretty tough down here), which coincidentally helps them keep the base roughly near the pole. Here's a couple pictures of the previous base in use from 1975-2005 (there was another base even before that built in the 1950s, currently buried in the ice):
|Old dome base|
|Inside the old dome base|
Every New Years Day, at noon, they have a ceremony where they move the official marker. In this video, they have all of us present passing the US flag in an arc from the old location to the new (about 10 yards).
The winter-staff includes a station machinist, whose responsibilities include machining a new Pole marker. This is a photo as it was unveiled: