What makes the South Atlantic a region

One territory, three chapters

Until 2009 the group was called St Helena and Dependencies, and Ascension and Tristan da Cunha were dependencies of Saint Helena inside it. The St Helena, Ascension and Tristan da Cunha Constitution Order 2009 came into force on 1 September 2009, gave each island group a chapter of the constitution to itself and put the three on equal standing. The machinery stayed single: one governor, resident in Jamestown, one legal system, and an administrator on Ascension and another on Tristan.

The catalogue files all of it as one record because the codes do. ISO 3166-1 assigns SH to the territory whole. AC and TA exist for Ascension and Tristan da Cunha as exceptionally reserved codes, held at the request of the Universal Postal Union rather than issued as country codes of their own, so a roster keyed on ISO has a single row where the ocean has three groups of islands.

What the distance costs

Reaching Saint Helena meant a five-day voyage from Cape Town until scheduled commercial flights began in October 2017. The flight from Johannesburg takes about six hours and runs weekly, with a monthly service on to Ascension. Tristan da Cunha has no airstrip. It is reached by ship from Cape Town, about 2,800 kilometres and roughly a week at sea across a handful of sailings a year, and passengers come ashore from an anchored vessel by pontoon or inflatable.

The populations are counted island by island and do not describe the same kind of place. Saint Helena recorded 4,439 residents at the 2021 census, on 122 square kilometres. Ascension holds about 800 people on 88 square kilometres and no right of abode at all: everyone present holds a fixed-term employment contract or accompanies somebody who does, and leaves when it ends. Tristan da Cunha has around 250. All of them left in October 1961, when the volcano erupted beside the settlement and 264 islanders were carried by way of Cape Town to Southampton. Most were back by 1963.

Sea, mostly

In November 2020 the territory declared a marine protection zone of 687,247 square kilometres around Tristan da Cunha, closing about 90% of those waters to fishing and to every other extractive use. The land it answers to is measured in hundreds of square kilometres.

Where the edges are argued

The UN Statistics Division files Saint Helena under Western Africa in the M49 standard, and states that its groupings are a statistical convenience implying nothing about political affiliation. This catalogue keeps Africa as the continent and files the territory apart from West Africa instead. Both readings put the same islands in the same ocean, and they differ over whether land 1,950 kilometres offshore is grouped with the mainland nearest to it or held separate.

Other land in the same water is filed elsewhere or not at all. The Falkland Islands are recorded under South America, here and in M49. South Georgia and the South Sandwich Islands and Bouvet Island carry ISO codes and no settled population, and neither appears on the roster. What is left in the South Atlantic, once those decisions are made, is the territory this page holds.