Island provides an excellent opportunity to measure the rate of glacial retreat as an indicator of climate change. Available records show no apparent change in glacier mass balance between 1874 and 1929. Between 1949 and 1954, marked changes were observed to have occurred in the ice formations above on the southwestern slopes of Big Ben, possibly as a result of volcanic activity. By 1963, major recession was obvious below on almost all glaciers, and minor recession was evident as high as . Retreat of glacier fronts across Heard Island is evident when comparing aerial photographs taken in December 1947 with those taken on a return visit in early 1980. Retreat of Heard Island glaciers is most dramatic on the eastern section of the island, where the termini of former tidewater glaciers are now located inland. Glaciers on the northern and western coasts have narrowed significantly, while the area of glaciers and ice caps on Laurens Peninsula have shrunk by 30% - 65%. During the time period between 1947 and 1988, the total area of Heard Island's glaciers decreased by 11%, from 288 km2 (roughly 79% of the total area of Heard Island) to only 257 km2. A visit to the island in the spring of 2000 found that the Stephenson, Brown and Baudissin glaciers, among others, had retreated even further. The terminus of Brown Glacier has retreated approximately 1.1 kilometres since 1950. The total ice-covered area of Brown Glacier is estimated to have decreased by roughly 29% between 1947 and 2004. This degree of loss of glacier mass is consistent with the measured increase in temperature of +0.9 °C over that time span. The coastal ice cliffs of Brown Glacier and Stephenson Glacier, which in 1954 were over high, had disappeared by 1963 when the glaciers terminated as much as inland. Baudissin Glacier on the north coast has lost at least , and Vahsel Glacier on the west coast has lost at least . Winston Glacier, which retreated approximately between 1947 and 1963, appears to be a very sensitive indicator of glacier change on the island. The young moraines flanking Winston Lagoon show that Winston Glacier has lost at least of ice within a recent time period. The glaciers of Laurens Peninsula, whose maximum elevation is only 500 m above sea level, are smaller and shorter than most of the other Heard Island glaciers, and therefore much more sensitive to