Sea Ice and Paleoceanographic Conditions in the Amundsen Gulf, Canadian Arctic during the Late Holocene

Canada's Arctic region is projected to undergo significant changes in response to future climate change, particularly in regards to sea ice cover. However, despite their potential relevance for understanding future changes, the spatial and temporal dynamics of paleoclimatic and sea ice proxies are poorly known in many Arctic locations. Examinations of long term changes in the abundance and composition of foraminiferal assemblages within the Amundsen Gulf allows some reconstruction of the dynamics of paleo-sea ice cover since the last glaciation. The Canadian Arctic Shelf Exchange Study (CASES) and ArcticNet have collected sediment cores and surface samples from 2002 to 2006 in the Beaufort Sea, Amundsen Gulf and the interstitial waters of the Canadian Arctic Archipelago. In the summer of 2004, a transect of five boxcores through the Amundsen Gulf, ranging from 15 to 35 cm in length, were collected from depths of 172 to 569 m. The five cores correlate chronostratigraphically with radiocarbon AMS ages, and are compared to two previously analysed cores from the Gulf, one of which was located at the front of the former ice margin. Spatial distributions of foraminiferal assemblages were assessed from surface sediments collected across the Beaufort Shelf and Amundsen Gulf. Assemblage differences were characteristic of different oceanic environments. These correlations were used to infer paleoenvironmental conditions, including sea ice cover and freshwater influx throughout the Holocene. Paleoclimatic reconstructions using foraminiferal abundances and assemblages from the Amundsen Gulf transect provide insights on spatial and temporal variations in oceanographic and sea ice conditions within an area of the Canadian Arctic that has not been previously investigated. These results may suggest how this region will respond to continued changes in climate.