DOI: 10.1016/j.gloplacha.2015.06.006
论文题名: Water level history for Lake Turkana, Kenya in the past 15,000years and a variable transition from the African Humid Period to Holocene aridity
作者: Bloszies C. ; Forman S.L. ; Wright D.K.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 132 起始页码: 64
结束页码: 76
语种: 英语
英文关键词: African Humid Period
; Holocene aridity
; Lake Turkana water level
; Monsoon variability
; Relict beaches
Scopus关键词: Atmospheric temperature
; Atmospheric thermodynamics
; Beaches
; Catchments
; Climate change
; Oceanography
; Runoff
; Stratigraphy
; Surface waters
; Water levels
; Enhanced convection
; Holocenes
; Humid periods
; Monsoon variability
; Sea surface temperature (SST)
; Walker circulation
; West African Monsoon
; Western indian oceans
; Lakes
; aridity
; catchment
; chronology
; climate oscillation
; climate variation
; geomorphology
; Holocene
; humid environment
; monsoon
; raised beach
; sea surface temperature
; sedimentology
; stratigraphy
; water level
; Younger Dryas
; Atlantic Ocean
; East African Lakes
; Kenya
; Lake Turkana
; Rift Valley
英文摘要: Relict beaches adjacent to Lake Turkana, Kenya provide a record of water level variability for the Late Quaternary. This study focused on deciphering the geomorphology, sedimentology, stratigraphy and 14C chronology of strand plain sequences in the Kalokol and Lothagam areas, at the western margin of the Lake. Nine >30m oscillations in water level were documented between ca. 15 and 4ka. The earliest lake level oscillation between ca. 14.5 and 13ka is not well constrained with water level to at least 70m above the present surface and subsequently fell to at least 50m. Lake level increased to at least 90m between ca. 11.2 and 10.4ka, post Younger Dryas cooling. Water level fell by >30m by 10.2ka, with another potential rise at ca. 8.5ka to >70m above current level. Lake level regressed by >40m at 8.2ka coincident with cooling in the equatorial eastern Atlantic Ocean. Two major >70m lake level oscillations centered at 6.6 and 5.2ka may reflect enhanced convection with warmer sea surface temperatures in the western Indian Ocean. The termination of the African Humid Period occurred from ca. 8.0 to 4.5ka and is characterized by highly variable lake level (±>40m), rather than one monotonic fall in water level. This lake level variability reflects a complex response to variations in the extent and intensity of the East and West African Monsoons near geographic and topographic limits within the catchment of Lake Turkana. Also, for this closed lake basin excesses and deficits in water input are amplified with a cascading lake effect in the East African Rift Valley and through the Chew Bahir Basin. The final regression from a high stand of >90m above the present lake began at 5.2ka and water level was below 20m by 4.5ka; and for the remainder of the Holocene. This sustained low stand is associated with weakening of the West African Monsoon, a shift of the mean position of Congo Air Boundary west of the Lake Turkana catchment and with meter-scale variability in lake level linked to Walker circulation across the Indian Ocean. 14.5 and 4.5ka. © 2015 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84936874941&doi=10.1016%2fj.gloplacha.2015.06.006&partnerID=40&md5=7e9b6cfd1af3e2ebca129f283de0c028
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11500
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: Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, United States
Recommended Citation:
Bloszies C.,Forman S.L.,Wright D.K.. Water level history for Lake Turkana, Kenya in the past 15,000years and a variable transition from the African Humid Period to Holocene aridity[J]. Global and Planetary Change,2015-01-01,132.