DOI: 10.1016/j.gloplacha.2016.11.002
论文题名: Evidence of El Niño driven desiccation cycles in a shallow estuarine lake: The evolution and fate of Africa's largest estuarine system, Lake St Lucia
作者: Humphries M.S. ; Green A.N. ; Finch J.M.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2016
卷: 147 起始页码: 97
结束页码: 105
语种: 英语
英文关键词: Climate change
; Coastal lake evolution
; Drought
; El Niño
; Lake St Lucia
Scopus关键词: Chloride minerals
; Climate change
; Climatology
; Driers (materials)
; Drought
; Ecosystems
; Estuaries
; Nickel
; Coastal ecosystems
; Coastal lake
; Estuarine systems
; Freshwater supply
; Natural variation
; Sedimentary records
; Seismic profiling
; Southern Hemisphere
; Lakes
英文摘要: Projections of an increase in drought frequency and intensity over the next century are expected to have severe implications for a number of globally important coastal ecosystems. In this paper, we present geochemical data from three sediment cores extracted from the main depositional basins of Lake St Lucia, Africa's largest estuarine system. Lake St Lucia is subject to extreme natural variations in salinity. The sedimentary record documents the evolution of the system from a relatively deep-water, open lagoon to a confined, shallow estuarine lake that today is highly sensitive to changes in freshwater supply. This is particularly evident in the northern portions of the system, where the presence of distinct halite-enriched horizons document episodes of prolonged drought. The lateral persistence of these halite layers, as revealed by seismic profiling, point to a system-wide onset of desiccation associated with a major shift in the regional hydroclimate. The most severe drought events identified, which may have lasted several years, occur at ~ 1100 and 1750 cal year BP, and are associated with known peaks in El Niño frequency and intensity. Our analyses suggest that past cycles of desiccation and hyper-salinity have been controlled by climatic changes related to ENSO intensification. This study provides a valuable new record from a key ENSO-sensitive region of the Southern Hemisphere. Our findings have important relevance for understanding ENSO variability across the Indo-Pacific region and the influence exerted on systems sensitive to changes in moisture balance. © 2016 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994831210&doi=10.1016%2fj.gloplacha.2016.11.002&partnerID=40&md5=0b2546c048c15cd5914a411143a339fb
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11589
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, South Africa
Recommended Citation:
Humphries M.S.,Green A.N.,Finch J.M.. Evidence of El Niño driven desiccation cycles in a shallow estuarine lake: The evolution and fate of Africa's largest estuarine system, Lake St Lucia[J]. Global and Planetary Change,2016-01-01,147.