DOI: 10.1038/ngeo2181
论文题名: Silica burial enhanced by iron limitation in oceanic upwelling margins
作者: Pichevin L.E. ; Ganeshram R.S. ; Geibert W. ; Thunell R. ; Hinton R.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 7 起始页码: 541
结束页码: 546
语种: 英语
Scopus关键词: burial (geology)
; concentration (composition)
; diatom
; iron
; marine sediment
; nutrient limitation
; opal
; sediment core
; sediment trap
; silica
; silicon
; upwelling
; Gulf of California
; Pacific Ocean
; Pacific Ocean (East)
; Bacillariophyta
英文摘要: In large swaths of the ocean, primary production by diatoms may be limited by the availability of silica, which in turn limits the biological uptake of carbon dioxide. The burial of biogenic silica in the form of opal is the main sink of marine silicon. Opal burial occurs in equal parts in iron-limited open-ocean provinces and upwelling margins, especially the eastern Pacific upwelling zone. However, it is unclear why opal burial is so efficient in this margin. Here we measure fluxes of biogenic material, concentrations of diatom-bound iron and silicon isotope ratios using sediment traps and a sediment core from the Gulf of California upwelling margin. In the sediment trap material, we find that periods of intense upwelling are associated with transient iron limitation that results in a high export of silica relative to organic carbon. A similar correlation between enhanced silica burial and iron limitation is evident in the sediment core, which spans the past 26,000 years. A global compilation also indicates that hotspots of silicon burial in the ocean are all characterized by high silica to organic carbon export ratios, a diagnostic trait for diatoms growing under iron stress. We therefore propose that prevailing conditions of silica limitation in the ocean are largely caused by iron deficiency imposing an indirect constraint on oceanic carbon uptake. © 2014 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106599
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of Geosciences, Grant Institute, University of Edinburgh, West Main Road, Edinburgh EH9 3JW, United Kingdom; Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208, United States
Recommended Citation:
Pichevin L.E.,Ganeshram R.S.,Geibert W.,et al. Silica burial enhanced by iron limitation in oceanic upwelling margins[J]. Nature Geoscience,2014-01-01,7(7)