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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Luke Skinner, Earth Sciences

Co-Supervisor: Neil Davies, Earth Sciences

Brief summary: 
Using novel high-resolution sedimentological, mineralogical and geochemical analyses of super-flood deposits recovered from the James Bay Lowlands to assess the timing, duration and hydraulics of the massive deluge that accompanied the final disintegration of the Laurentide ice sheet, and that may have triggered the ‘8.2 kyr cold-event’ via the perturbation of the North Atlantic ocean circulation.
Importance of the area of research concerned: 
Towards the end of the last deglaciation, when the Laurentide ice-sheet had receded into the Hudson Bay lowlands of Canada, a single ‘super-lake’ comprising roughly 114,000 km3 formed along its southern margin. As the deglaciation continued, leads forming in the remnant Laurentide ice-sheet allowed the ice dam between the superlake Agassiz and the Tyrrell Sea (i.e. the Hudson Strait and Hudson Bay area) to be breached. This is believed to have resulted in a flood of freshwater into the Hudson Strait and North Atlantic ~ 8,470 cal ka BP, and by analogy with the Heinrich events of the last glaciation, is proposed to have triggered the 8,200 BP cold-event via its impact on the Atlantic overturning circulation. This event provides a unique natural experiment for developing our understanding of the nature of ice sheet collapse, and the hydraulics of super-floods (and e.g. subglacial lake drainage), and their climatic implications.
Project summary : 
As the most significant abrupt climate event known to have occurred under interglacial conditions, the 8,200 BP cold-event represents an important ‘test case’ for our conceptual models of freshwater-forced climate change, and our understanding of the mechanisms of freshwater outbursts and ice sheet collapse. Relatively little direct field-evidence of the timing and hydraulics of the flood event that accompanied the demise of the Laurentide ice-sheet, and that is presumed to have triggered the 8,200 BP cold-event, has been gathered since the 1970s. This project will target uplifted flood deposits from the James Bay Lowlands that offer an unprecedented opportunity to look into the progression of the last Lake Agassiz outburst flood in extreme detail, based on novel scanning technology, geochemical analyses and micromorphology investigations.
What will the student do?: 
The student will undertake a micromorphological and sedimentological study of the flood deposits, and will carry out mineralogical and geochemical analyses on specific constituents of the flood deposits in order to identify changes depositional conditions and sediment origin. If possible, work will involve a field expedition to the James Bay Lowlands to recover new material for analysis.
References - references should provide further reading about the project: 
Barber, D. C., Dyke, A., Hillaire-Marcel, C., Jennings, A. E., Andrews, J. T., Kerwin, M. W., Bilodeau, G., McNeely, R., Southon, J., Morehead, M. D., and Gagnon, J.-M. (1999). Forcing of cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes. Nature 400, 344-348.
Clarke, G. K. C., Leverington, D. W., Teller, J. T., and Dyke, A. S. (2004). Paleohydraulics of the last outburst flood from glacial Lake Agassiz and the 8200 BP cold event. Quaternary Science Reviews 23, 389-407.
Roy, M., Dell’Oste, F., Veillette, J. J., de Vernal, A., Hélie, J. F., & Parent, M. (2011). Insights on the events surrounding the final drainage of Lake Ojibway based on James Bay stratigraphic sequences. Quaternary Science Reviews, 30(5), 682-692. doi:https://doi.org/10.1016/j.quascirev.2010.12.008
Applying
You can find out about applying for this project on the Department of Earth Sciences page.
Department of Earth Sciences Graduate Administrator
Dr Neil Davies
Dr Luke Skinner