The formation of Mega Scale Glacial Lineations: insights into the mechanisms of ice stream flow

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Ice streams are very fast flowing corridors of ice and represent the main arteries by which ice sheets lose mass to the ocean. Thus, ice stream behaviour is crucial to any models which attempt to predict the effect of global warming on polar ice masses and sea level rise. Three competing hypotheses have been suggested to explain ice stream motion, all centred on the interaction of the ice with its bed.Mega Scale Glacial Lineations (MSGL)are landforms that are formed at the ice-bed interface under ice streams. The mechanism of their formation is not known though some theories have been developed. However, it is clear that the formation of MSGL represents a crucial element in solving the puzzle of enigmatic ice stream dynamics. In other words, by understanding how MSGL form it will be possible to clarify the mechanism of ice stream motion, thus enhancing the predictive capability of models that analyze the effects of climate change on the vulnerable polar ice masses.This project proposes to map and quantitatively analyze the largest (tens of thousands landforms) dataset of MSGL ever created, from onshore and submarine settings from all over the world. The metrics and spatial distribution of these landforms will be studied in great detail with rigorous statistical analyses and state-of-the-art GIS and Remote Sensing techniques. The spatial variability of the morphometric parameters will be compared to that of the topography, geology and palaeo-geography of the palaeo-ice stream beds where MSGL are found in. The project will also characterize at an unprecedented level of details the internal composition of MSGL, with a combination of techniques never deployed before in the study of an individual glacial bedform. The results from the combined (morphometrical and sedimentological) approach will be used to test hypotheses and models of formation of these landforms and shed light on processes at the ice-bed interface. Ultimately, the quantitative results will be directly used to refine and develop numerical models of ice stream flow.Matteo Spagnolo's expertise and experience in GIS and Remote Sensing applied to glacial geomorphology, coupled with his strong interest in extending his skills into glacial sedimentology and ice modelling, are the essential ingredients that guarantee the success of this new investigator project. An array of international renowned experts are project partners and will support the work of the proponent.