A multi-proxy reconstruction of tropical cyclone variability during the past 800 years from Robinson Lake, Nova Scotia, Canada

Abstract

This study presents a multi-proxy reconstruction of tropical cyclone (TC) activity for the past 800 years from Robinson Lake, located on the north Atlantic seaboard of Nova Scotia, Canada. Two sediment cores were extracted from Robinson Lake and were dated by 210Pb and 14C methods, and analyzed for organic matter content, sediment grain size, and a range of elements and elemental ratios determined by XRF core scanning. A distinct sand layer in the most recent sediments is attributed to Hurricane Juan, which struck the coast of Nova Scotia on September 29, 2003. Our study shows that peaks in grain size farther down-core are generally correlated with abrupt increases in Br and Br/Ti. XRF-derived Br measurements are an indicator of marine organic carbon (MOC), and the increases in Br likely reflect incursions of marine water and nutrients into the lake as a result of storm surges. The results show that the period from ~1475 to 1670 CE contains at least 3–4 storm beds, and are interpreted as the most active TC period within the last ~800 years for this region. Our results are consistent with recent research from Salt Pond, Massachusetts (Donnelly et al. 2015), which provides evidence for heightened TC activity during the same period as our study at Robinson Lake. Our study represents one of the highest latitude paleotempestological studies from the North Atlantic basin which will help the testing of hypotheses concerning long-term changes in North Atlantic TC activity under future climate change scenarios.