Do the anomalous fluctuations of Sólheimajökull reflect ice-divide migration?

Ice-divide migration may explain the pattern of Holocene glacier fluctuations around the Mýrdalsjökull ice cap in southern Iceland. On at least three occasions Sölheimajokull, the principal outlet glacier on the southwest flank of the ice cap, has exceeded the Little Ice Age limits of recent centuries that mark the maximum extent of neighbouring glaciers in the Holocene. Bedrock divides beneath the Mýrdalsjökull ice cap do not coincide with present ice divides. It is suggested that the ice divide migrated during the course of ice-cap growth. At various stages during the Holocene (7000-4500, c. 3100, 1400-1200 BP) Sólheimajokull could have drained more of the ice cap than today, so becoming more advanced than neighbouring glaciers. In the Little Ice Age ( c. AD 1600–1900) the glacier could have had a smaller catchment as a result of ice-divide migration, resulting in a more inhibited advance compared with neighbouring glaciers which reached their Holocene maximum at that time. Identification of ice-divide migration is important for palaeoclimatic reconstructions because of the need to recognize different responses of glaciers to climate if one is to use their fluctuations as indicators of change.