Fortunately, governmental decree and agreement has helped define that for us in the form of the Antarctic Treaty, which was put in force in 1961 by a coalition of countries.

It defines Antarctica as being all lands and ice shelves south of 60° South Latitude, which includes places as far north as the South Orkney Islands, where we’ll be tomorrow; Elephant Island, where we were today; and of course, the Antarctic Peninsula, where we were the three days prior.

The Antarctic circle, which is at 66° 33′ 39”, defines the region below (south of) which the sun will not set on the day of the winter solstice in December (summer in Antarctica), and will not rise on the day of the summer solstice in June (winter in Antarctica).

And finally, there’s the Subantarctic. This is the area north of 60° south latitude, north some degrees to include nearby islands, such as South Georgia Island (where we will be on Saturday for a week or so). There is no hard and fast definition of where the sub-Antarctic ends, with islands as far north as the Falkland Islands (where we will be in about 10 days) being included in the Subantarctic (or sub-Antarctic if you prefer).

Hope that clears it up! It certainly did for us.