Sources and oceanic paths of large meltwater discharge events and their roles in abrupt holocene climatic events

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My research program will provide a better understanding of abrupt climatic changes that occurred during the last 11,000 years, a topic currently of interest to the United Nations Intergovernmental Panel on Climate Change (IPCC), in view of the potentially serious implications such abrupt changes have on human societies. These events are difficult to replicate using numerical climate models, so paleoclimatic proxy data is indispensable to their study. It is not possible now to identify the primary cause of abrupt climatic events among meltwater discharges, natural climatic variability, shifts in oceanic currents, and solar influence. Since there is not even consensus about the source and routing (path) of some large meltwater releases that occurred during the last deglaciation, it is not possible to confirm or rule out their role in abrupt climate cooling events. This project will focus on meltwater source and paths believed to have caused such severe cooling events as the Younger Dryas and the Preboreal oscillation. I will verify if large amounts of meltwater from glacial Lake Agassiz (and/or other glacial lakes) were discharged through the St. Lawrence River between 11,000 and 7000 years ago. In order to do so, I will study high resolution marine sediment cores from strategic locations to detect any meltwater releases through that route. Sea surface temperature and salinity will be reconstructed using dinoflagellate cysts data and transfer functions. These paleoceanographic records will also be used to document the frequency and amplitude of natural climatic variability in that region. Knowing the frequency of these oscillations might help to identify their causes and will contribute to the better knowledge of our climate system.