Five thousand years of sediment transfer in a high arctic watershed recorded in annually laminated sediments from Lower Murray Lake,Ellesmere Island,Nunavut, Canada |
| |
| Authors: | Timothy L Cook Raymond S Bradley Joseph S Stoner Pierre Francus |
| |
| Institution: | (1) Department of Geosciences, Climate System Research Center, University of Massachusetts, Amherst, MA 01003, USA;(2) College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA;(3) Institut national de la recherche scientifique, Centre Eau, Terre et Environment, Quebec, QC, Canada, G1K 9A9;(4) GEOTOP, Geochemistry and Geodynamics Research Center, Montreal, QC, H3C 3P8, Canada |
| |
| Abstract: | Sediments in Lower Murray Lake, northern Ellesmere Island, Nunavut Canada (81°21′ N, 69°32′ W) contain annual laminations
(varves) that provide a record of sediment accumulation through the past 5000+ years. Annual mass accumulation was estimated
based on measurements of varve thickness and sediment bulk density. Comparison of Lower Murray Lake mass accumulation with
instrumental climate data, long-term records of climatic forcing mechanisms and other regional paleoclimate records suggests
that lake sedimentation is positively correlated with regional melt season temperatures driven by radiative forcing. The temperature
reconstruction suggests that recent temperatures are ~2.6°C higher than minimum temperatures observed during the Little Ice
Age, maximum temperatures during the past 5200 years exceeded modern values by ~0.6°C, and that minimum temperatures observed
approximately 2900 varve years BC were ~3.5°C colder than recent conditions. Recent temperatures were the warmest since the
fourteenth century, but similar conditions existed intermittently during the period spanning ~4000–1000 varve years ago. A
highly stable pattern of sedimentation throughout the period of record supports the use of annual mass accumulation in Lower
Murray Lake as a reliable proxy indicator of local climatic conditions in the past.
|
| |
| Keywords: | Varves Holocene paleoclimate Arctic Lake sediments Ellesmere Island |
| 本文献已被 SpringerLink 等数据库收录！ |
|
