AN 8000-YEAR RECORD OF CLIMATE AND ENVIRONMENTAL CHANGE FROM LAKE SANDSVATN, FAROE ISLANDS

The Faroe Islands are located in the North Atlantic Ocean where climate is influenced by major oceanic and atmospheric circulation patterns. Paleoclimate records from the region can therefore provide important perspectives on the long term variability of these regional climate components. The Faroe Islands also have an interesting history of human colonization, which likely did not occur until the mid-first millennium AD, potentially involving significant landscape impacts. This study reconstructs Holocene paleoenvironmental conditions during the past 8000 cal yr BP in the Faroe Islands based on analysis of a 305 cm sediment record from Lake Sandsvatn (8 m a.s.l.), located along the coast of Sandoy. A chronology for the record was developed based on 12 radiocarbon dated plant fragments. Sediment characteristics including organic content, C/N ratios, sulfur, grain size, magnetic susceptibility, and high-resolution scanning XRF data were analyzed to infer the timing and impact of past climate and environmental changes. The base of the record contains coarse sediment with shell fragments, high magnetic susceptibility, high calcium, and low organic matter. We interpret this to represent the Storegga Tsunami, which impacted the region c. 8 ka BP. Sedimentation following the tsunami (7600-2300 cal yr BP) is silty with frequent peaks in sand content and organic matter, high sulfur, and low C/N values. High frequency variations reflect a high energy coastal environment impacted by storms that periodically deliver and rework coarse sediment. From 2300-1400 cal yr BP, the record is characterized by an abrupt onset of extremely high organic matter and C/N values with low sulfur and titanium. This interval could mark a period of landscape disturbance due to human colonization, or may reflect natural changes associated with expansion of peatlands. From 1400 cal yr BP to present, sediments are similar to the mid-Holocene with variable organic matter and sulfur and low C/N values and magnetic susceptibility. Trends in this record are similar to others from the region and highlight the challenges of interpreting data from shallow coastal lakes. With this record, we are working to develop an improved understanding of North Atlantic climate fluctuations and better assess the characteristics of early human landscape disturbance.