The 6 bases - beginnings & ends
'full' means all occupation by all residents, and science operational.
'vert.' means vertical access from the snow surface
'horiz.' means horizontal access from the sea ice
See also "Abandoned bases, visits to" in the General Index.
For the positions of the bases, see Movement of Halley 1956 - 2016.
An Investigation into Evolving Design and Construction of Research Stations in Antarctica
and their Approaches to Enable Human Habitation of Extreme Environments.