Holocene paleoceanography and climate variability in the Western Arctic Ocean

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The Arctic Ocean is a sensitive responder to climate changes as well as active driver of global and regional atmospheric and oceanic circulation patterns. In order to document long-term natural climate cycles and predict future climate trends for the Arctic Ocean, one needs to reconstruct the oceanic dynamics locked in sedimentary records in which hydrologic and oceanographic responses to climatic changes are represented by the variability of sedimentary and geochemical tracers. Among these tracers, the clay minerals (e.g., illite, kaolinite, chlorite and smectite), radiogenic isotopes [e.g., neodymium (Nd), lead (Pb) and strontium (Sr)] and sedimentary protactinium-231/thorium-230 (231Pa/230Th) records from marine sediments are useful tools for paleoceanographic and paleoclimatic reconstructions. Under this context, the overall objective of this research program is to use a powerful multi-proxy approach combining clay mineral composition, elemental geochemistry, radiogenic isotope compositions (Nd, Pb and Sr) in both the clay-size fraction and authigenic (seawater-derived) ferromanganese coatings, and sedimentary 231Pa/230Th ratios from identical sediment core samples from the continental margins of the Canadian Beaufort and Chukchi seas, in order to document Holocene changes in continental inputs, deep-Arctic circulation and current transport related to climate change. Hence, because Holocene sedimentation rates in the continental margins of the Canadian Beaufort and Chukchi seas reach up to 120 cm/ka, this innovative research program will offer a unique opportunity to reconstruct the natural evolution and variability of climatic and oceanographic conditions in the Western Arctic Ocean during the last 10,000 years at decadal to millennial timescales. These results not only will help to significantly advance our understanding on the future Arctic climate and oceanographic dynamics, but will also provide high temporal resolution data that will help to better constrain the regional climate models. Finally, this unique pool of mineralogical and geochemical tools will also offer a dynamic training environment for highly qualified personnel with access to expertise in different fields of marine geology and geochemistry.