DOI: 10.1016/j.epsl.2018.06.017
Scopus记录号: 2-s2.0-85049972417
论文题名: Constraining the evolution of Neogene ocean carbonate chemistry using the boron isotope pH proxy
作者: Sosdian S.M. ; Greenop R. ; Hain M.P. ; Foster G.L. ; Pearson P.N. ; Lear C.H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 498 起始页码: 362
结束页码: 376
语种: 英语
英文关键词: boron isotopes
; carbonate system
; foraminifera
; Miocene
; Neogene
Scopus关键词: Calcium compounds
; Carbon
; Carbon dioxide
; Carbonate minerals
; Carbonation
; Ecosystems
; Isotopes
; Oceanography
; Repair
; Seawater
; Sensitivity analysis
; Boron isotopes
; Carbonate system
; foraminifera
; Miocene
; Neo genes
; Climate change
; boron isotope
; carbonate system
; glacial-interglacial cycle
; isotopic composition
; Neogene
; paleoceanography
; paleoclimate
; pH
; planktonic foraminifera
; Foraminifera
; Tobrilus
英文摘要: Over the course of the Neogene, the Earth underwent profound climatic shifts from the sustained warmth of the middle Miocene to the development of Plio-Pleistocene glacial–interglacial cycles. Major perturbations in the global carbon cycle have occurred alongside these shifts, however the lack of long-term carbonate system reconstructions currently limits our understanding of the link between changes in CO2, carbon cycling, and climate over this time interval. Here we reconstruct continuous surface ocean pH, CO2, and surface ocean aragonite saturation state using boron isotopes from the planktonic foraminifer Trilobatus trilobus and we perform a sensitivity analysis of the key variables in our calculations (e.g. δ11Bsw, [Ca]sw, CCD). We show that the choice of δ11Bsw influences both seawater pH and CO2 while [Ca]sw reconstructed dissolved inorganic carbon exerts a significant influence only on CO2. Over the last 22 Myr, the lowest pH levels occurred in the Middle Miocene Climate Optimum (MMCO; 17–14 Myr ago) reaching ∼7.6±0.1 units in all our scenarios. The extended warmth of the MMCO corresponds to mean CO2 and aragonite saturation state levels of 470–630 ppm and 2.7–3.5, respectively. Despite a general correspondence between our CO2 record and climate, all CO2 scenarios show a peak at ∼9 Ma not matched by corresponding changes in climate reconstructions. This may suggest decoupling (i.e. significant CO2 change without a discernible climate response) for a limited interval in the Late Miocene (11.6–8.5 Ma), although further refinement of our understanding of the temporal evolution of the boron isotopic composition of seawater is necessary to fully evaluate the nature of the relationship between CO2 and climate. Nonetheless, from our long-term view it is clear that low-latitude open ocean marine ecosystems are unlikely to have experienced sustained surface pH and saturation levels below 7.7 and 1.7, respectively, during the past 14 million years (66% CI). © 2018 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109760
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Cardiff University, School of Earth & Ocean Sciences, Cardiff, CF10 3AT, United Kingdom; Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, Southampton, United Kingdom; University of St. Andrews, School of Earth and Environmental Sciences, St. Andrews, United Kingdom; Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, United States
Recommended Citation:
Sosdian S.M.,Greenop R.,Hain M.P.,et al. Constraining the evolution of Neogene ocean carbonate chemistry using the boron isotope pH proxy[J]. Earth and Planetary Science Letters,2018-01-01,498