600 Years of Late Holocene Climate Variability Inferred from a Varved Proglacial Sediment Record Linnévatnet, Svalbard, Norway

• Main Authors: Dowey, Colin W, Retelle, Michael J
• Format: Text
• Language: unknown
• Published: SCARAB 2013
• Subjects: paleoclimate; svalbard; proglacial; lake; sediment; Linnébreen; Linnédalen; Linnéelva; Linnévatnet; Norway; Svalbard; Spitsbergen
• Online Access: https://scarab.bates.edu/geology_theses/7; https://scarab.bates.edu/cgi/viewcontent.cgi?article=1006&context=geology_theses

The varved proglacial sediment record preserved in Linnévatnet, Svalbard, Norway contains a valuable climate signal that can be used to reconstruct local Late Holocene climate variability. Two cores analyzed in this study, LH-4 and LH-Long were collected in May, 2012 from a distal location 1.5 km from the main inlet. This distal location allowed for a long record to be collected and the lack of sub-annual layers allowed for accurate measurement of varve thickness, the primary climate proxy. Through analysis of the Linnédalen proglacial system, and comparisons to the instrumental record it is clear that varve thickness is directly related to Linnéelva yearly sediment flux, Linnébreen mass balance, and summer temperature. Varve thickness and other potential climate proxy measurements were accurately placed back through time through the development of a plutonium-verified varve chronology. The varve chronology derived from counting and measuring yearly lamination couplets throughout core LH-4, is one of the highest resolution chronologies established in Linnévatnet. From the interpretation of the Linnévatnet climate proxies and comparisons with other Svalbard paleoclimate reconstructions four periods of warm summer temperatures and four periods of cool summer temperatures in Linnédalen were projected. The warm periods, defined from AD pre- 1379 to late 1390’s, from AD 1760’s-1790’s, from AD 1850’s to AD 1870’s, from AD 1980’s-present, relate to either steady increases in LH-4 varve thickness or intervals where varve thickness remains above average. The cool periods, defined from AD 1400-1450’s, AD 1550’s-1580’s, AD 1790’s-1850’s and AD 1950’s-1980’s, relate to either steady decreases in LH-4 varve thickness or intervals where varve thickness remains below average. Further comparisons between the paleoclimate reconstruction presented in this study and regional-scale Late Holocene climate reconstructions indicate strong correlation between climate conditions in Linnédalen and NAO mode. This relationship confirms the influence of the NAO on the climate of western Spitsbergen.