PECS is applicable to polar or polar-style journeys operating in polar, sub-polar or non-polar regions. The single most important criteria is the surface over which a journey travels, which must be on land ice/snow, sea ice or frozen lake, and may include parts of adjoining ice-free areas.
Antarctica is recognised by the Antarctic Treaty System as ‘the area below 60º South Latitude, including all ice shelves’. Ice shelves are an extension of Antarctic land ice and part of the Antarctic continent. Their seaward perimeters, which are fronted by sea or annual sea ice, form part of the Antarctic coastline.
The Antarctic icecap is divided into the East and West Antarctic Ice Sheets, separated by the Transantarctic Mountains
Located mostly in the Arctic north polar region in the middle of the Northern Hemisphere, the Arctic Ocean (sometimes referred to as the Arctic Sea) is almost completely surrounded by Eurasia and North America. Arctic Ocean journeys travel primarily north of the Arctic Circle.
Subpolar environments include regions of the subarctic and subantarctic.
Subarctic areas are generally found between 50º and 70ºN and include much of Siberia, Kamchatka, Iceland, parts of Scandinavia and most of Canada's Northwest Territories and Alaska.
Subantarctic areas are generally found between 46º and 60ºS and include the islands or island groups south of 60º.
PECS can also be used to classify journeys in non-polar environments that provide conditions suitable for extended polar-style expeditions.
Such areas include the Patagonian icecaps, Lake Baikal and alpine regions.