'Little Ice Age' glaciation of Tröllaskagi peninsula,northern Iceland: climatic implications for reconstructed equilibrium line altitudes (ELAS)

Abstract

Comparison of the equilibrium line altitudes (ELAS) for the present (1980s) and the maximum 'Little Ice Age' depression determined for glaciers in the Skíõadalur/Svarfaõardalur area of the Tröllaskagi peninsula, northern Iceland, shows a rise of c. 50 m over the last 100-150 years. Meteoro logical data suggest that over the same period the mean summer temperature at the equilibrium line changed by at least 2.0°C. Application of a model of the relationship between mean summer temperature and winter accumulation at the ELA for glaciers in southern Norway suggests that such a temperature change should have led to a movement of up to 300 m in the ELA. The discrepancy between the observed and expected results is accounted for by an almost two-fold increase in winter accumulation. The application of this model highlights the potential importance of interpreting changes in ELA in terms of both temperature and precipitation, and the results from northern Iceland demonstrate that in some areas accumulation changes can almost balance considerable changes in temperature. There is also potential through this method for hypothesizing atmospheric changes as explanations of the climatic changes interpreted.