Post-glacial climate change and its effect on a shallow dimictic lake in Nova Scotia, Canada
This study of a lake in Lunenburg County gives us a good idea of Nova Scotia’s historical climate, vegetation and habitation potential since the last Ice Age, and the animation below illustrates some of the changes noted in the following paper abstract.
A high-resolution, multi-proxy lake sediment record was used to establish the timing of Holocene environmental change in Canoran Lake, southwest Nova Scotia, Canada. Canoran Lake is a small, shallow (11 m) lake with two ephemeral inlets and an outlet. The site was deglaciated at ca. 15,300 cal (calibrated) year BP and elevated %C values indicate the establishment of a productive aquatic environment that is consistent with Allerød warming.
The Allerød was interrupted by rapid air temperature cooling during the Younger Dryas (ca. 12,900–11,600 cal year BP). The Early Hypsithermal (ca. 11,600–8,500 cal year BP) was relatively warm and wet. A slight increase in clastic input occurred between 9,100 and 8,500 cal year BP but d15N, d13C, and HI values imply that the lithostratigraphic response may not be indicative of climate-induced change.
The strong proxy response between 8,500 and 8,000 cal -year BP was likely due to cooling and drying coincident with the 8.2 k year event. The climate was relatively warm and dry during the Late Hypsithermal
(ca. 8,000–3,500 cal year BP). None of the proxies’ exhibit notable change during the 5,500 cal year BP hemlock decline, indicating that ecological change was likely due to a pathogen attack. Post-Hypsithermal (modern) climate was characterized by an increase in precipitation and a decrease in air temperatures from ca. 3,500 to 700 cal year BP (top of core).
J Paleolimnol DOI 10.1007/s10933-009-9310-2
Brent Lennox, Ian Spooner, Timothy Jull, William P. Patterson
Received: 14 April 2008 / Accepted: 14 January 2009
Springer Science+Business Media B.V. 2009