The positions of seven markers, erected on the Greenland Ice Sheet were accurately determined by members of the British North Greenland Expedition 1952–54. In three cases the height of a fixed mark above the snow surface was measured. It is hoped that in a decade or two these will be found by future expeditions and their heights redetermined so as to enable a measurement to be made of the rate of movement of the ice sheet and the net accumulation.
The following information about the markers is published for future reference. The probable error in altitude is 10 m. in all cases, and the probable errors are 0.1′ in latitude and 0.5′ in longitude except in the case of A. 19 and “Northice”.
B. 9. Position: lat. 77° 19.4′ N., Iong. 27° 55.5′ W. Altitude 1713 m. The marker is an open square pyramid with an aluminium sheet as top mark. The lowest of the top screws was 7.9 m. above the snow surface on 1 May 1954.
A. 14. Position: lat. 77° 27.7′ N., Iong. 29° 03.8′ W. Altitude 1812 m. The marker is an iron pipe about 15 cm. diameter.
A. 19. Position: lat. 77° 30′ 01″ N., long. 30° 10′ 43″ W. Altitude 1878 m. Probable error 3″ in latitude, 12″ in longitude. Marker similar to B.9. The upper screw at the apex was 7.9 M. above the snow surface on 3 May 1954.
B. 32. Position: lat. 77° 41.5′ N., long. 33° 32.5′ W. Altitude 2120 m. The marker is a pole 12 cm. diameter with an orange box as top mark.
“Northice.” Position: lat. 78° 04′ 16″ N., long. 38° 29′ 25″ W. Altitude 2345 m. The marker is the lattice anemometer mast. The top cross-bar was 9.1 m. above the snow surface in June, 1953.
B. 73. Position: Iat. 78° 01.1′ N., long. 45° 47.0′ W. Altitude 2514 m. A pole with canvas top mark.
B. 112. Position: lat. 77° 23.8′ N., long. 49° 26.0′ W. Altitude 2530 m. A pole.
