Antarctica is a continent -- one of seven on earth. It is unlikely to disappear.
People disappear by falling into a crevasse, by slipping under the sea ice or by wandering off alone in to the Antarctic wild.
It will only disappear if earth disappears. It won't!
Possibly.
no
Yes but only very rarely - that is why Antarctica is a desert.
There is no city -- nor has there ever been a city -- in Antarctica.
Antarctica has not ever been involved in war.
No.
There is no evidence that Christopher Columbus ever reached Antarctica.
no
Yes, some things can disappear. By disapear, if you mean visually, sure; it happens all the time.
Yes, no one could ever disappear without a trace.