Download or read book A Correlation of Western Arctic Ocean Sedimentation During the Late Holocene with an Atmospheric Temperature Proxy Record from a Glacial Lake in the Brooks Range, Alaska written by Jeffrey Michael Harrison and published by . This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The delivery of sediment to the Alaskan continental shelf is largely associated with sea-ice drift and wind driven Arctic Ocean circulation patterns that have varied during the Holocene. This study presents a comparison of two high-resolution proxy records from the western Arctic over the past 2,000 years. To provide variations of sedimentation patterns in the Arctic Ocean (e.g., sea-ice transport, density flows, ocean currents), the grain size distributions were measured in a piston core (HLY02-04 JPC16) from the eastern Chukchi Sea at a higher resolution than previously reported. A revised JPC16 age-depth model was used in this analysis (Darby et al., 2012). The sediment core, collected on the east flank of Barrow Canyon (72.1555°N, 153.50817°W, ~1300 mwd), preserves a record of local variations in sedimentation mechanisms in the Chukchi-Beaufort Seas. A Varimax-rotated Principle Component Analysis (VPCA) was conducted on the grain-size data from JPC16. We inferred three principal components (PCs) of sediment deposition at the core site related to anchor ice, nepheloid flows, and suspension freezing based on variations in grain-size distributions from a Malvern Mastersizer sediment analysis. This interpretation is consistent with previous downcore analysis by Darby et al. (2009) on multiple western Arctic Ocean cores. A fourth, much less significant mode, is related to resuspension and deposition connected to intermittent suspension and ocean currents. While all VPCA modes showed increased variability since 200 yr BP, components related to sea-ice showed the highest positive loadings between 2000-1300 cal yr BP. The most likely cause of positive anomalies observed in these two components is associated with increased ice melt and settling of sediment, or a greater influx of sea-ice into Alaskan waters. It can therefore be argued that oscillations in these modes are closely related to changes in atmospheric temperature or oscillations in the atmosphere-ocean circulation patterns, primarily the Arctic Oscillation. The high-resolution record of sediment deposition in the Arctic Ocean allowed for direct correlation with an atmospheric climate proxy as recorded by varve thickness measurements retrieved from a glacial lake located in the Brooks Range (Bird et al., 2009). The time interval investigated here shows a significant relationship between marine sea-ice sedimentation and atmospheric temperature (r = 0.7). This analysis suggests that warmer atmospheric intervals are likely related to greater sea-ice melt and sedimentation of entrained sediments.