Glacial dynamics of the Laurentide Ice Sheet along a land-to-sea transect in East Canada
The Labrador Sea is a pivotal region for the climate system of Earth, as it is home to the Atlantic Meridional Overturning Circulation (AMOC) current. The AMOC has been influenced by the growth and decay of large ice sheets on both shores of the Labrador Sea during the Quaternary period. This thesis focuses on the glacial dynamics of the Laurentide Ice Sheet (LIS) in East Canada during the Late Pleistocene era. A more comprehensive understanding of the LIS facilitates future prediction of changes and influences exerted by the Greenland Ice Sheet. A land-to-sea approach is employed, with two distinct working areas being considered: the terrestrial Lake Manicouagan (Manikuakan, according to Innu toponymy) and the marine Labrador Shelf. This transect follows the chronology of retreat of the LIS. In this thesis, marine geophysical datasets, mainly 2D multi-channel seismic reflection profiles, are interpreted. In particular, the sedimentary sequence of Lake Manicouagan is delineated for the first time using one of the seismic reflection datasets, and the thickness of this sequence is estimated. Furthermore, this thesis describes for the first time potential interglacial sediments that are part of two preserved glacial cycles present on the Labrador Shelf. The reconstruction of the ice margin and dynamics of the LIS during the Late Pleistocene era is facilitated by the use of glacial landforms on the Labrador Shelf. The discovery of subglacial channels and grounding-zone wedges (GZWs) has enabled a more comprehensive understanding of the past behaviour of the LIS. The results of this research highlight the potential of both Lake Manicouagan and the Labrador Shelf as rich paleoclimate archives. These regions have the potential to reveal important information during future drilling campaigns about environmental parameters of the Late Pleistocene from a region that is key for the planet's climate system.
Preview
Rights
Use and reproduction:
Please note that individual components of the publication may be subject to other licensing or copyright conditions.