Iceberg calving and the glacioclimatic record

Abstract

Glacier fluctuations can yield climatic information. However, the relationship between climate and calving glaciers is not straightforward. Iceberg calving introduces instability to the glacier system causing glaciers to oscillate asynchronously with each other and with noncalving glaciers, and out of phase with climate change. Calving rates are controlled primarily by water depth, but, for any given depth, are an order of magnitude greater in tidewater than in freshwater. Calving dynamics are poorly understood, but differ between temperate and cold glaciers, and between grounded and floating termini. Nonclimatic behaviour of calving glaciers has been documented in a large number of locations, both in historical time and during the Late Glacial and Holocene. Interactions between calving dynamics, sedimentation and topographic geometry can partially decouple calving glaciers and marine ice sheets from climate, initiating independent advance/retreat cycles; it is therefore rarely possible to make reliable inferences about climate from their oscillations.