Accumulation - although there is very little precipitation at Halley, large amounts of snow is blown onto the ice shelf. Items on the surface become buried and regularly have to be dug out and lifted onto the surface. There can be as much as two metres of accumulation in a year.
Bealach - a Gaelic word for a col or mountain pass.
Caird Coast - the north-west coast of Coats Land (the area of the Antarctic that Halley is in). It was surveyed in January 1915 by Ernest Shackleton’s British International Trans-Antarctic Expedition (BITAE) expedition. It was named after Sir James Caird (1864 - 1954), ship-owner and jute manufacturer of Dundee, who subscribed towards the cost of the expedition [1]. Around the Hinge Zone the Caird Coast is where the Antarctic Plateau flows onto the sea and becomes the Brunt Ice Shelf.
Caboose - small hut on skis that sleeps four people and has a stove in it for heat
Chasm - in the past the ice shelf has split from the mainland revealing an area of open sea that has then frozen. In places icebergs have also floated into this area and become frozen in providing some spectacular scenery.
Contrast - the ability to see details in the snow. When it’s cloudy features on the snow surface are not visible and everything looks white - this is poor contrast and it makes travelling difficult.
Creek - a small inlet in the ice cliffs. They tend to fill with snow and allow easy access from the ice shelf onto the frozen sea. There is a series of Creeks to the north of Halley numbered from one to ten.
Crevasse - a crack in the ice of an ice shelf or glacier. They’re often covered with snow at the surface and so difficult to see.
Crossed stakes - crossed flags or stakes are used to indicate where you shouldn’t go. On the drum line between Halley and Second Chasm there are a set of crossed stakes to indicate where you need to begin linked travel, after travelling from base unlinked.
Dingle - excellent visibility.
Doo. - a skidoo.
Drift - when the wind blows loose snow over the surface. It generally happens when the wind is stronger than 15 knots. When the wind is stronger than 20 knots there will be snow up to head height and the visibility is seriously reduced.
Drum line - a line of empty 45 gallon drums up to 500 metres apart, on the surface of the snow showing the route between two places. These drums have to be dug out of the snow and placed on the surface again around two times a year because of accumulation.
Field - a part of the Antarctic that’s not part of a base. A Field Trip is a trip away from the base, often camping.
GA - General Assistant, although this is generally used to refer to a Field GA. Field GAs are very experienced mountaineers who help us to travel in the Antarctic. For the recreational field trips during the winter at Halley we have one GA along with three other people.
Grounding Zone - an alternative name for features such as the Rumples.
Horizon. - Horizontal Definition. The ease with which the sky can be distinguished from the land. Similar to contrast, cloud cover can give a poor horizon.
Ice shelf - where ice is flowing off the main Antarctic plateau and is floating on the sea while still joined to the plateau. Halley Research Station is built on the Brunt Ice Shelf.
Jumar - a mechanical device that attaches to a rope and will only move one way along the rope. Used for climbing up ropes to escape from crevasses.
Kts. - an abbreviation for knots. A measurement of speed; one knot is slightly faster than one mile an hour.
Linked travel - when travelling in a region that may contain crevasses, on skidoos or on foot, you travel in pairs, linked to you partner by a rope. If one of you should fall into a crevasse then the other can stop you from going too far and help you to escape.
Probing - trying to break through the surface snow layer to find crevasses.
Rumples - an area of the Brunt Ice Shelf to the north-east of Halley where the shelf is running over rocks sticking up from the seabed. Its full name is the McDonald Ice Rumples and was roughly charted in January 1915 by Shackleton’s BITAE expedition. It was named after Allan McDonald of the British Association of Magallanes, Punta Arenas Chile, who was mainly responsible for raising funds (in 3 days) for sending the British relief expedition in Emma on the third abortive attempt, in July 1916, to rescue the Endurance Party on Elephant Island [1].
Sastrugi - ripples on the snow surface caused by the wind - have a look at the background of this diary.
Sched - a pre-arranged conversation over the radio.
Skidoo - small tracked vehicle with a ski at the front for steering. Each skidoo can carry one person and tow a sledge.
Slot - crevasse.
Survey pole - a pole left upright in the snow. Periodically its position is measured and allows the movement of the ice shelf to be measured.
Unit - a sledge, tent and all the other gear needed to survive in the Antarctic. A half-unit has a smaller tent and less equipment, and is taken on day trips in case you are forced to spend an unplanned night away from your main camp.
Vis. - visibility
Wx - weather
[1] The History of Place-Names in the British Antarctic Territory, G. Hattersley-Smith, British Antarctic Survey, 1991.