DOI: 10.1016/j.epsl.2020.116645
论文题名: Three North African dust source areas and their geochemical fingerprint
作者: Jewell A.M. ; Drake N. ; Crocker A.J. ; Bakker N.L. ; Kunkelova T. ; Bristow C.S. ; Cooper M.J. ; Milton J.A. ; Breeze P.S. ; Wilson P.A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 554 语种: 英语
中文关键词: 87Sr/86Sr
; Bodélé Depression
; dust source
; North Africa
; radiogenic isotopes
; εNd
英文关键词: Budget control
; Climate change
; Geochemistry
; Health hazards
; Image enhancement
; Isotopes
; Reliability analysis
; Satellite imagery
; Sediments
; Dust accumulation
; Dust source areas
; Geochemical fingerprints
; Lacustrine sediments
; North Atlantic Ocean
; Primary productivity
; Radiogenic isotopes
; Systematic analysis
; Dust
; aerosol composition
; atmospheric transport
; dust
; geochemistry
; long range transport
; point source
; radionuclide
; satellite imagery
; substrate
; Atlantic Ocean
; Atlantic Ocean (North)
; Bodele
; Chad
; North Africa
英文摘要: North Africa produces more than half of the world's atmospheric dust load. Once entrained into the atmosphere, this dust poses a human health hazard locally. It also modifies the radiative budget regionally, and supplies nutrients that fuel primary productivity across the North Atlantic Ocean and as far afield as the Amazonian Basin. Dust accumulation in deep sea and lacustrine sediments also provides a means to study changes in palaeoclimate, particularly those associated with rainfall climate change. Systematic analysis of satellite imagery has greatly improved our understanding of the trajectories of long-range North African dust plumes, but our knowledge of the dust-producing source regions and our ability to fingerprint their contribution to these export routes is surprisingly limited. Here we report new radiogenic isotope (Sr and Nd) data for sediment samples from known dust-producing substrates (dried river and lake beds), integrate them with published isotope data and weight them for dust source activation. We define three isotopically distinct preferential dust source areas (PSAs): a Western, a Central and an Eastern North African PSA. More data are needed, particularly from the Western PSA, but our results show a change in PSA dust source composition to more radiogenic Nd- and less radiogenic Sr-isotope values from west to east, in line with the overall decreasing age of the underlying bedrock. Our data reveal extreme isotopic heterogeneity within the Chadian region of the Central PSA, including an extremely distinctive geochemical fingerprint feeding the Bodélé Depression, the most active dust source on Earth. Our new analysis significantly improves the reliability by which windblown dust deposits can be geochemically fingerprinted to their distant source regions. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165529
Appears in Collections: 气候变化与战略
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作者单位: University of Southampton, National Oceanography Centre Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom; Department of Geography, Bush House North East Wing, Kings College London, London, WC2B 4BG, United Kingdom; Department of Archaeology, Max Planck Institute for the Science of Human History, Kahlaische Strasse 10, Jena, D-07745, Germany; Department of Earth and Planetary Sciences, Birkbeck University of London, Malet Street, London, WC1E 7HX, United Kingdom
Recommended Citation:
Jewell A.M.,Drake N.,Crocker A.J.,et al. Three North African dust source areas and their geochemical fingerprint[J]. Earth and Planetary Science Letters,2021-01-01,554