Large variations in the Holocene marine radiocarbon reservoir effect reflect ocean circulation and climatic changes

Hua, Quan, Webb, Gregory E., Zhao, Jian-xin, Nothdurft, Luke D., Lybolt, Matthew, Price, Gilbert J. and Opdyke, Bradley N. (2015) Large variations in the Holocene marine radiocarbon reservoir effect reflect ocean circulation and climatic changes. Earth and Planetary Science Letters, 422 33-44. doi:10.1016/j.epsl.2015.03.049

Author Hua, Quan
Webb, Gregory E.
Zhao, Jian-xin
Nothdurft, Luke D.
Lybolt, Matthew
Price, Gilbert J.
Opdyke, Bradley N.
Title Large variations in the Holocene marine radiocarbon reservoir effect reflect ocean circulation and climatic changes
Journal name Earth and Planetary Science Letters   Check publisher's open access policy
ISSN 0012-821X
Publication date 2015-07-15
Year available 2015
Sub-type Article (original research)
DOI 10.1016/j.epsl.2015.03.049
Open Access Status
Volume 422
Start page 33
End page 44
Total pages 12
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2016
Language eng
Formatted abstract
Accurate radiocarbon dating of marine samples requires knowledge of the marine radiocarbon reservoir effect. This effect for a particular site/region is generally assumed constant through time when calibrating marine 14C ages. However, recent studies have shown large temporal variations of several hundred to a couple of thousand years in this effect for a number of regions during the late Quaternary and Holocene. Here we report marine radiocarbon reservoir correction (ΔR) for Heron Reef and Moreton Bay in southwestern (SW) Pacific for the last 8 ka derived from 14C analysis of 230Th-dated corals. Most of our ΔR for the last ∼5.4 ka agree well with their modern value, but large ΔR variability of ∼410 yr (from trough to peak) with possible decadal/centennial fluctuations is evident for the period ∼5.4–8 ka. The latter time interval also has significant variations with similar features in previously published ΔR values for other sites in the Pacific, including southern Peru–northern Chile in southeastern (SE) Pacific, the South China Sea, Vanuatu and Papua New Guinea, with the largest magnitude of ∼920 yr from SE Pacific. The mechanisms for these large ΔR variations across the Pacific during the mid-Holocene are complex processes involving (1) changes in the quantity and 14C content of upwelled waters in tropical east Pacific (TEP) (frequency and intensity of ocean upwelling in the TEP, and contribution of Subantarctic Mode Water to the upwelled waters, which is influenced by the intensity and position of southern westerly winds), and (2) variations in ocean circulation associated with climate change (La Niña/El Niño conditions, intensity of easterly trade winds, positions of the Intertropical Convergence Zone and the South Pacific Convergence Zone), which control the spreading of the older upwelled surface waters in the TEP to the western sites. Our results imply the need for employing temporal changes in ΔR values, instead of constant (modern) values, for age calibration of Holocene marine samples not only for the SW Pacific sites but also for other tropical and subtropical sites in the Pacific.
Keyword Marine radiocarbon reservoir effect
U-Th dating
Ocean circulation
Climate change
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Earth Sciences Publications
Official 2016 Collection
School of Biological Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 8 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 8 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 05 May 2015, 00:26:18 EST by System User on behalf of School of Earth Sciences