2000 Years of Climate Variablity from Arctic Lakes

Climate of the past millennium inferred from varved proglacial lake sediments on northeast Baffin Island, Arctic Canada

Thomas, E.K. and Briner, J.P.

Big Round

Link to Abstract

Study Location

Big Round Lake is a proglacial lake located on northeast Baffin Island in Arctic Canada. The lake is on an inter-fiord highland at 180 m a.s.l., 70 km south of Clyde River, the closest town with a weather station. Surface and long sediment cores were recovered from Big Round Lake in May 2006.

Climate Proxy

Varve thickness:

  • Varve thickness in Big Round Lake is related to late-summer (July-August-September) temperature. During this time of year, the lake is ice-free and glacier and snow meltwater carry sediment into the lake.

Results

Varve thickness in Big Round Lake are significantly correlated with Clyde River late summer temperature in the instrumental period, and we use the relationship between the two to reconstruct late summer temperature back 1000 years. The Little Ice Age was 1.7°C cooler than today, and pre-20th century warm periods were more than 1°C cooler than today. The 20th century is unique in this record in that it exhibits sustained high varve-inferred temperatures. The annually resolved varve-thickness record from Big Round Lake is used to explore the influence of climate forcing mechanisms in this part of the Arctic. Periods of low volcanic activity generally coincide with the thickest varves (e.g., late 16th c. and early 20th c.).

Related Websites