Because Antarctica has no permanent resident population and belongs to no single nation, it would depend which base you were on. The Australian and UK bases would call him Father Christmas, and the US bases would call him Santa Claus.
People in Antactica all came there from other countries, and they would call Santa whatever they call him in their native languages.
Santa Claus
Santa Claus
In Thai, Santa Claus is ซานตาคลอส.
Because there are no children living in Antarctica, Santa avoids this extreme environment on his holiday rounds.
They call him Santa Claus, or Santa.
We canadians call him Santa Claus, also. Don't worry about it.
He is still called Santa Claus there, in Alaska.
Santa Claus, or Father Christmas.
They call him Santa Claus. Exactly the same name as you call him.
People in Pakistan call Santa Claus Baba Christmas
People in England often call him Father Christmas, but some of them call him Santa Claus as well.