| Summary: | The study of past circum-Atlantic ice sheet motions and instabilities and the reconstrucction of related changes in the strength of the North Atlantic deep bottom-currents is fundamental to understand the effects of past climate changes, and subsequently to predict the effect of future changes. An important part of the reseach efforts produced in this regard have focused on the Lauretide ice-sheet (LIS), leaving the potential role of the European Ice Sheet (EIS) relatively unexplored. Similarly, the millennial changes in the bottom-currents strength, their potential relationship to the Atlantic Meridional Overturning Circulation (AMOC) variations and the deep and intermediate water masses re-accommodations remains also very weakly constrained. The main objective of this thesis is to study the interrelated dynamics of the Northern Hemisphere ice sheets during the Last Glacial Period (LGP) and their coupling with the Thermohaline circulation,( THC), AMOC and the climate, focussing on the time period of the last ~80 ka, during which the North Hemisphere climate and the ice-sheets volumes fluctuated rapidly. The study is based on high-resolution sedimentological, geochemical and environmagnetic analyses of the sedimentary record of the last 135 ka based on five well-dated piston cores from the Galicia Interior Basin in the Northwest Iberian Margin. The results show the southernmost evidence of meltwater pre-events from the EIS during the initial stages of HS1, HS2, and HS4, and IRD from the LIS and EIS during the final stages of these stadials, and throughout HS3, HS5 and HS6. The relevance of this findings reside in the potencial for large freshwater discharges like these, to act as an additional forcing mechanism for AMOC weakening; and subsequently, for ice sheets collapses, prolonging the Heinrich Stadials. The results also show the intensification of bottom current velocities during HS3, HS5, HS6, the Last Glacial Maximum, and through the final stages of the HS1, HS2 and HS4. However, these increases in the ...
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