The Loch Lomond Readvance on the Isle of Skye, Scotland: Glacier reconstruction and palaeoclimatic implications

Abstract

AbstractGeomorphological mapping of southern Skye indicates evidence for a single readvance of locally‐nourished glaciers. These comprised a major icefield that occupied c. 155 km2of the main mountain area, a small icefield c. 10 km2in extent in the Kyleakin hills and ten corrie glaciers with a total area of c. 16 km2. The absence of Lateglacial pollen sites, shorelines and periglacial features within the limits of local glaciation implies a Loch Lomond Readvance age for this glacial event. The area‐weighted mean equilibrium line altitude (ELA) of the reconstructed Loch Lomond Readvance glaciers (319 m) conforms with a regional eastwards rise in ELAs that indicates dominant westerly airstreams during the Loch Lomond Stadial. An easterly decline in ELAs across the former icefields is interpreted in terms of easterly transfer of snow across ice‐sheds by westerly winds, though the altitudes of corrie glacier ELAs suggest that the dominant snow‐bearing winds were southerlies. Calculations based on the area‐weighted mean ELA for the major icefield (308 m) indicate a stadial mean July sea‐level temperature of c. 6 °C. The anomalously low gradients of certain former icefield outlet glaciers are attributed to deformation of subglacial sediment, an effect that may vitiate the assumption of linear ablation/accumulation gradients in the calculation of former ELAs for reconstructed glaciers.