Presentation by Dr. Danielle LeBlanc.
Title:
Exploring North Atlantic Paleo-Ice Sheet Paradigms
Abstract:
In this talk, I explore the behavior of North Atlantic ice sheets during the Pleistocene using a combination of geochemical methods and iceberg modeling. Cosmogenic nuclide (10Be and 26Al) data from last glacial North Atlantic ice-rafted debris suggest the Laurentide Ice Sheet was persistent in some sectors for many interglacial cycles. This challenges the idea of complete deglaciation during every interglacial period. A dual-proxy approach, using cosmogenic nuclides (10Be) and 40Ar/39Ar, applied to Heinrich (H) and background layers reveals similar sediment sourcing for H3 and H6. In contrast to other Heinrich layers, which exhibit localized sourcing, these layers suggest a more complex, multi-source origin, pointing to an alternative mechanism for these events. New iceberg modeling results indicate the European Ice Sheet may have played a larger role in Heinrich events than previously recognized, challenging the view of a single-ice sheet initiation. These findings offer new perspectives on past North Atlantic ice sheet stability and the role of ice and meltwater in driving past climate changes.
