Olivia Gibb

M. Sc. Thesis

Foraminiferal Indicators of Paleoceanographic and Sea-Ice Conditions in the Amundsen Gulf and Viscount Melville Sound, Canadian Arctic

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Sediment cores were collected from the Canadian Arctic Archipelago to reconstruct the region's oceanographic and sea ice history via foraminiferal proxies. Foraminiferal species assemblages reflect changes in sea ice cover due to the dissolution of calcareous foraminifera during increased productivity in ice-free waters. The upper five cm of sediment of the core located in the Amundsen Gulf is characterized by a predominantly agglutinated foraminiferal assemblage that spanned the last century, indicative of a seasonally ice-free Amundsen Gulf. In contrast to the recent assemblage, a predominantly calcareous assemblage indicated carbonate preservation within the Amundsen Gulf during a period of perennial ice extending back to the 9th century AD. During the Medieval Warm Period and the Anthropocene, two recent periods of warmer climate, foraminiferal proxies indicated different sea ice regimes. These results suggest that the factors forcing sea ice extent have changed in recent decades.

Pages: 145
Supervisor: David Scott