New developments for paleoclimate studies

Lake sediments are useful to track a history of long-term environmental changes.  Environmental monitoring often extends back no more than a few decades, and is largely non-existent in remote places like the Arctic, which is currently experiencing some of the most rapid environmental change on Earth. Archival sediment records in the form of dated sediment cores can greatly enhance our knowledge of past environmental change because they can extend the time scales of studies by thousands of years and they are broadly distributed in the environment. Recent developments in sediment biomarker analysis and interpretation are helping us to learn more about long-term changes in biodiversity, climate, migratory animals, and even human occupation in different parts of the world.  This seminar explores how paleoclimate proxies, such as the glycerol dialkyl glycerol tetraethers (GDGTs) that track past temperature and other climatic anomalies, are enhancing paleoenvironmental studies. I will use two examples: (1) Pacific salmon in Alaska and on Canada’s northern west coast:  We are developing geochemical techniques to track past Pacific salmon abundance from sediment records and we are applying GDGT methods to show how Pacific salmon populations responded historically to the warm and cool phases of the Pacific Decadal Oscillation. (2) Ancient Thule and Dorset cultures: Information is sparse on human occupation in Canada’s Arctic, however sediment studies are revealing new details about the history of human occupation in the Arctic, including the timing of arrival and site abandonment, and how human history may have been shaped by climate.