Variation in glacier length and ice volume of Rabots Glaciär, Sweden, in response to climate change, 1910-2003

Historical records, photographs, maps and measurements were used to determine changes in the length, geometry and volume of Rabots Glaciär, Sweden, in response to a ∼1°C warming that occurred early in the 20th century. The glacier's initial rate of retreat from its 1910 maximum was ∼2.0 ma^-1. After a sharp increase to ∼11.7 ma^-1 between 1933 and 1946, the mean retreat rate decreased to ∼5.5 ma^-1 between 1946 and 1959. Thereafter the rate of retreat increased to ∼11.0 ma^-1 and has remained relatively constant to the present time. Concomitant decreases in ice volume were estimated to be 77.3 × 10⁶ m³ between 1910 and 1959, 51.1 × 10⁶ m³ between 1959 and 1980, at least 10.4 × 10⁶ m³ between 1980 and 1989, and 14.4 × 10⁶ m³ between 1989 and 2003. The total volume change over the last 93 years is estimated at ∼153.2 × 10⁶ m³ corresponding to 1.6 × 10⁶ m³ a^-1. The magnitude of the ongoing changes in length and volume suggests that Rabots Glaciär has not yet completed its response to the earlier climatic warming. In contrast, several nearby glaciers, most notably Storglaciären, have completed their adjustments and established new steady-state profiles as a result of having shorter response times.