New Zealand (Ross Dependency)
There are two permanent bases in the Ross Dependency. One is McMurdo station, owned by the US, and the other is Scott Base, operated by New Zealand's Ross Dependency Agency. The base resides on Ross Island and is a mere 3km from the massive US McMurdo Station. It is a year-round base with a summer population of 85 and an over-winter crew of less than 15.
Station Manager - Scott Base Antarctica New Zealand Private Bag 4745 Christchurch 8140 NEW ZEALAND
I've read that philatelic mail is not handled at Scott Base but is instead dealt with at the Ross Depenency Agency office in Christchurch, NZ. It is never sent to the Antarctic base. New Zealand post produces Ross Dependency stamp issues once a year, in November, and the issues remain available for purchase for at least that long also. You CAN NOT use New Zealand stamps on mail that is to be postmarked with the Dependency Agency postmark.
If it's just the Ross Dependency postmark you want, trying sending a request and cover (with Ross Dependency stamps applied) directly to the Christchurch Mail Service Center at:
Philatelic Mail Christchurch Mail Service Centre Private Bag 55055 Orchard Road Christchurch 8154
Additional information about polar philately and other stamp-related topics can be found in my Blog
last updated 28 October 2015