BRIKSDALSBREEN, WESTERN NORWAY - CLIMATIC EFFECTS ON THE TERMINAL RESPONSE OF A TEMPERATE GLACIER BETWEEN AD 1901 AND 1994

Annual measurements of the frontal variations of Briksdalsbreen are compared with twentieth-century records of summer temperature, winter precipitation and mass budget to evaluate the effects of climatic change on the glacier fluctuations. Frontal variations are shown to be determined by both summer temperature and winter precipitation. Between AD 1901 and 1931 the glacier front was in a more-or-less stable position. Warm summers in the 1930s and 1940s caused a significant retreat of the glacier, reaching a maximum rate of annual retreat of 84 m in 1948. Cooler summers in the late 1940s led to a stabilization of the glacier front from 1952. Between 1987/88 and 1993/94 the terminus advanced 231 m, 155 m of which has occurred after 1992. The increased glacier net mass balance in western Norway after the 1988/89 season resulted in the largest annual glacier advances measured this century at Briksdalsbreen (75 and 80 m in 1992/93 and 1993/94, respectively). Present knowledge about glacier history in western Norway since the termination of the last glaciation about 9000 years ago suggests that annual glacier expansions of such magnitude only occurred during the 'Little Ice Age' (c. AD 1650-1920). The lag time of frontal response of Briksdalsbreen to a change in annual net balance has been calculated to be 3-4 years, which confirms that glacier termini can react rapidly to short-term climatic changes.