Donec ut ex ac nulla pellentesque mollis in a enim. Praesent placerat sapien mauris, vitae sodales tellus venenatis ac. Suspendisse suscipit velit id ultricies auctor. Duis turpis arcu, aliquet sed sollicitudin sed, porta quis urna. Quisque velit nibh, egestas et erat a, vehicula interdum augue.
Position fixes made at the British Antarctic Survey station, Halley, on the Brunt Ice Shelf are considered for the period 1968–82. These show an initial westward velocity of approximately 400 ma−1 rising to over 700 m a−1 by the end of the period. The data are well fitted by two straight lines. The first for 1968–71 has a slope 430 m a−1 in agreement with that found by Thomas (1973) for the period up to 1968. The second for 1972–83 has a slope 740 ma −1, a large increase sustained for up to 10 years.read more