Abrupt Climatic Changes and Meltwater Discharges
along the Eastern Canadian Margin

Dr. Elisabeth Levac
Environmental Studies and Geography

PROFILE

Dr. Levac is an assistant professor in the Department of Environmental Studies and Geography at Bishop’s University, where she teaches in the areas of physical geography, oceanography, and weather systems. She completed a B.Sc. in Physical Geography and a M. Sc. in Earth Sciences at the Université du Québec à Montréal, and a Ph.D. degree in Earth Sciences at Dalhousie University. In 2005, she worked as a post-doctoral fellow for the Halifax Pollen and Spores Monitoring Experiment at St. Mary’s University. Dr. Levac conducts research in paleoceanography and paleoclimatology, more specifically on abrupt climate changes during the Holocene, on interactions between climate systems and human cultures, and on pollen monitoring (please see http://www.ubishops.ca/research/levac2.html). She works in collaboration with researchers from the Geological Survey of Canada, Memorial University of Newfoundland and St. Francis Xavier University. She is part of the Environmental Sciences Research Centre (ESRC) http://esrc.stfx.ca/. She is president-elect of the Canadian Association of Palynologists for 2008 http://www.scirpus.ca/cap/cap.shtml. She is adjunct professor at the Université de Sherbrooke, in the department of Géomatique Appliquée and is currently looking for master students to assist with her projects and work in her laboratory.

RESEARCH ACTIVITIES

Dr. Levac is studying the sources and path of large meltwater discharges to the North Atlantic during the last deglaciation to clarify the role of these events in the natural climatic variability and latitudinal differences along the Eastern Canadian Margin. More specifically, her research intends to reconstruct sea surface conditions from high resolution sedimentary records to precisely document the timing and duration of abrupt climatic change, and shed light on their causes. Professor Levac’s studies target different climatic events, time intervals, and locations.

1- Sources and oceanic paths of large meltwater discharge events and their roles in abrupt Holocene climatic events
The objectives of this project are to determine if meltwater was released through the St. Lawrence River at the time of the Younger Dryas and Preboreal Oscillation, the impact of meltwater influx on sea surface conditions over the Gulf of St. Lawrence and over the Scotian Shelf, and if millenial-scale climatic oscillations were superimposed onto the climatic events.

In order to do so, Dr. Levac uses reconstructions of sea surface conditions at locations along the expected path of the meltwater: the Western Laurentian Channel and the Northern Scotian Shelf.

This project is funded by two grants and funds are available for graduate students:

(NSERC discovery grant) 2007-2011; $109,000)

Acquisition of a microscope and a microwave digester for the study of abrupt climatic events in the last 11,000 years. (NSERC Research Tools and Instrument, Category 1 2007; $19,250)

2- The path of Lake Agassiz meltwater and its impact on Labrador Current
The objectives of this project are to define the path of the large meltwater release from Lake Agassiz around 8200 years ago, by reconstructing sea surface conditions at strategic locations along the path of the Outer Labrador Current. In doing so, she will determine the impact of meltwater influx on the Labrador Current, specifically the amplitude of sea surface temperature and salinity changes, obtain a tight age control for the timing and duration of the event, determine if it corresponds to the 8.2 ka event in Greenland, and determine whether the 8.2 ka event was superimposed onto a millenial-scale oscillations. If funding is approved, the role of solar forcing will also be examined.

Both Professor Levac’s studies will provide better paleoclimatic data against which numerical models of global warming can be tested. Professor Levac’s research will also contribute towards a better understanding of global warming’s potential impact on the climate of Eastern Canada and East Coast fisheries.

November 2007