Tracking millennial-scale Holocene glacial advance and retreat using osmium isotopes: Insights from the Greenland ice sheet

Quaternary Science Reviews
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Abstract

High-resolution Os isotope stratigraphy can aid in reconstructing Pleistocene ice sheet fluctuation and elucidating the role of local and regional weathering fluxes on the marine Os residence time. This paper presents new Os isotope data from ocean cores adjacent to the West Greenland ice sheet that have excellent chronological controls. Cores MSM-520 and DA00-06 represent distal to proximal sites adjacent to two West Greenland ice streams. Core MSM-520 has a steadily decreasing Os signal over the last 10 kyr (187Os/188Os = 1.35–0.81). In contrast, Os isotopes from core DA00-06 (proximal to the calving front of Jakobshavn Isbræ) highlight four stages of ice stream retreat and advance over the past 10 kyr (187Os/188Os = 2.31; 1.68; 2.09; 1.47). Our high-resolution chemostratigraphic records provide vital benchmarks for ice-sheet modelers as we attempt to better constrain the future response of major ice sheets to climate change. Variations in Os isotope composition from sediment and macro-algae (seaweed) sourced from regional and global settings serve to emphasize the overwhelming effect weathering sources have on seawater Os isotope composition. Further, these findings demonstrate that the residence time of Os is shorter than previous estimates of ∼104 yr.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Tracking millennial-scale Holocene glacial advance and retreat using osmium isotopes: Insights from the Greenland ice sheet
Series title Quaternary Science Reviews
DOI 10.1016/j.quascirev.2016.02.021
Volume 138
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) Pacific Coastal and Marine Science Center
Description 13 p.
First page 49
Last page 61
Online Only (Y/N) N
Additional Online Files (Y/N) N
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