ABSTRACT

Glacier surges are cyclic oscillations of velocity and mass resulting from internal dynamic instabilities. For surge-type glaciers, cycles of advance and retreat are decoupled from climate forcing, so it is important to consider the possibility that former glaciers may have been surge-type when making climatic inferences from their dimensions and chronologies. In this paper, climatic and glacier geometric data are used to show that Scotland was likely the location of a surge cluster during the Loch Lomond Stade (∼12.9–11.7 ka), with high probabilities of surging for outlets of the West Highland Icefield and the larger glaciers in the Inner Hebrides and Northern Highlands. Terrestrial and marine landforms consistent with surging occur in all of these areas, and it is proposed that surge-type glaciers existed on the Islands of Skye and Mull, in the Northern Highlands, and in a ‘surging arc’ along the western, southern and south-eastern margins of the West Highland Icefield. The possibility that surge-type glaciers were widespread in Scotland during the Loch Lomond Stade offers a fresh perspective on some long-standing issues, including the relationship between style of deglaciation and climate change, the climatic significance of glacial chronologies, palaeoclimatic reconstructions, and the interpretation of numerical model results.

摘要

冰川浪涌是由内部动态不稳定性引起的速度和质量的循环振荡。对于涌流型冰川，进退周期与气候强迫脱钩，因此在根据其维度和年代学进行气候推断时，重要的是要考虑前冰川可能是涌流型冰川的可能性。在本文中，气候和冰川几何数据被用来表明苏格兰很可能是 Loch Lomond Stade (~12.9–11.7 ka) 期间涌浪群的位置，西高地冰原出口和内赫布里底群岛和北部高地的较大冰川。所有这些地区都存在与涌动一致的陆地和海洋地貌，推测斯凯岛​​和马尔岛存在涌动型冰川，在北部高地，以及沿着西部高地冰原的西部、南部和东南边缘的“汹涌弧线”。在 Loch Lomond Stade 期间涌流型冰川在苏格兰广泛存在的可能性为一些长期存在的问题提供了新的视角，包括冰川消融方式与气候变化之间的关系、冰川年代学的气候意义、古气候重建以及数值模型结果的解释。