DOI: 10.1016/j.quascirev.2015.08.025
Scopus记录号: 2-s2.0-84945459270
论文题名: Interpretation of orbital scale variability in mid-latitude speleothem δ18O: Significance of growth rate controlled kinetic fractionation effects
作者: Stoll H. ; Mendez-Vicente A. ; Gonzalez-Lemos S. ; Moreno A. ; Cacho I. ; Cheng H. ; Edwards R.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 127 起始页码: 215
结束页码: 228
语种: 英语
英文关键词: Kinetic fractionation
; Orbital forcing
; Oxygen isotopes
; Speleothem
Scopus关键词: Atmospheric temperature
; Caves
; Deposition rates
; Growth rate
; Isotopes
; Kinetic theory
; Moisture
; Oceanography
; Oxygen
; Rain
; Surface waters
; Fractionation effects
; Hydrological cycles
; Kinetic fractionations
; Orbital forcing
; Oxygen isotopes
; Sea surface temperature (SST)
; Speleothem
; Temperature variation
; Kinetics
; fractionation
; hydrological cycle
; isotopic fractionation
; latitude
; orbit determination
; orbital forcing
; oxygen isotope
; paleoclimate
; precipitation assessment
; speleothem
; temperature effect
; Atlantic Ocean
; Atlantic Ocean (Subtropical)
; Spain
英文摘要: Oxygen isotopes have been the most widely used climate indicator in stalagmites, applied to reconstruct past changes in rainfall δ18O and cave temperature. However, the δ18O signal in speleothems may also be influenced by variable kinetic fractionation effects, here conceived broadly as fractionation effects not arising from temperature variation. The regional reproducibility of speleothem δ18O signals has been proposed as a way to distinguish the δ18O variations arising directly from changes rainfall δ18O and cave temperature, from variations due to kinetic effects which may nonetheless be influenced by climate. Here, we compare isotopic records from 5 coeval stalagmites from two proximal caves in NW Spain covering the interval 140 to 70 ka, which experienced the same primary variations in temperature and rainfall δ18O, but exhibit a large range in growth rates and temporal trends in growth rate. Stalagmites growing at faster rates near 50 μm/yr have oxygen isotopic ratios over 1‰ more negative than coeval stalagmites with very slow (5 μm/yr) growth rates. Because growth rate variations also occur over time within any given stalagmite, the measured oxygen isotopic time series for a given stalagmite includes both climatic and kinetic components. Removal of the kinetic component of variation in each stalagmite, based on the dependence of the kinetic component on growth rate, is effective at distilling a common temporal evolution of among the oxygen isotopic records of the multiple stalagmites. However, this approach is limited by the quality of the age model. For time periods characterized by very slow growth and long durations between dates, the presence of crypto-hiatus may result in average growth rates which underestimate the instantaneous speleothem deposition rates and which therefore underestimate the magnitude of kinetic effects. The stacked growth rate-corrected speleothem δ18O is influenced by orbital scale variation in the cave temperature and the δ18O of the ocean moisture source, but also by temporally variable fractionation in the hydrological cycle. The most salient trend is increased hydrological fractionation during the GI-22 period, when warmer sea surface temperatures in the subtropical Atlantic moisture source region may have favored greater precipitation amounts. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59805
Appears in Collections: 过去全球变化的重建
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作者单位: Dept. of Geology, University of Oviedo, Oviedo, Spain; Instituto Pirenaico de Ecologia, CSIC, Zaragoza, Spain; Dept. of Geology, University of Barcelona, Barcelona, Spain; University of Minnesota, Dept. of Earth Sciences, Minneapolis, United States; Xian Jiaotong University, Institute of Global Environmental Change, Xian, China
Recommended Citation:
Stoll H.,Mendez-Vicente A.,Gonzalez-Lemos S.,et al. Interpretation of orbital scale variability in mid-latitude speleothem δ18O: Significance of growth rate controlled kinetic fractionation effects[J]. Quaternary Science Reviews,2015-01-01,127