Climatic change in northern Ethiopia during the past 17,000 years: a diatom and stable isotope record from Lake Ashenge

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dc.contributor.author Marshall, Michael H.
dc.contributor.author Lamb, Henry F.
dc.contributor.author Davies, Sarah J.
dc.contributor.author Leng, Melanie J.
dc.contributor.author Kubsa, Zelalem
dc.contributor.author Umer, Mohammed
dc.contributor.author Bryant, Charlotte
dc.date.accessioned 2010-12-03T15:06:06Z
dc.date.available 2010-12-03T15:06:06Z
dc.date.issued 2009-08-01
dc.identifier.citation Marshall , M H , Lamb , H F , Davies , S J , Leng , M J , Kubsa , Z , Umer , M & Bryant , C 2009 , ' Climatic change in northern Ethiopia during the past 17,000 years: a diatom and stable isotope record from Lake Ashenge ' Palaeogeography, Palaeoclimatology, Palaeoecology , vol 279 , no. 1-2 , pp. 114-127 . en
dc.identifier.issn 0031-0182
dc.identifier.other PURE: 154659
dc.identifier.other dspace: 2160/5972
dc.identifier.uri http://hdl.handle.net/2160/5972
dc.description Marshall MH, Lamb HF, Davies SJ, Leng MJ, Kubsa Z, Umer M, Bryant C. 2009. Climatic change in northern Ethiopia during the past 17,000 years: a diatom and stable isotope record from Lake Ashenge. Palaeogeography, Palaeoclimatology, Palaeoecology, 279 (1-2), 114-127. Sponsorship: NERC/ Leverhulme Trust/ Royal Geographical Society en
dc.description.abstract Lake Ashenge, a closed-basin lake near the northernmost penetration of summer monsoon rains, is well placed to provide a continental record of past changes in the strength of the African monsoon system. Diatom and oxygen isotope analyses of the lake sediments confirm that the overall trend of climate change during the past 17,000 years was driven by precessional forcing, punctuated by abrupt shifts that may be linked to changes in Atlantic surface temperatures. The lake level was low from at least 17.2 to 16.2 cal kyr BP, and then rose between 16.2 and 15.2 cal kyr BP, which may represent a temporary reactivation of the monsoonal circulation system following its reduced activity during the Last Glacial Maximum. The lake was significantly low between 13.6 and ~ 11.8 cal kyr BP coinciding approximately with the Younger Dryas, but beginning 900 years before its recognised onset in the Greenland ice-core record. A major sedimentary hiatus, covering the interval ~ 11.8 to 7.6 cal kyr BP, was probably caused by an early Holocene lowstand, the precise timing of which cannot be determined because pre-lowstand sediments were eroded from the core site. The lake filled to its overflow from 7.6 cal kyr BP until 5.6 cal kyr BP, when the sediments record an abrupt lake response to the regional transition to arid conditions that mark the end of African Humid Period. Evidence is also presented for climate changes which may have been associated with the rise and fall of Aksum, Ethiopia's first great civilisation. en
dc.format.extent 14 en
dc.language.iso eng
dc.relation.ispartof Palaeogeography, Palaeoclimatology, Palaeoecology en
dc.subject Diatoms en
dc.subject Stable isotopes en
dc.subject Lake level en
dc.subject Monsoon en
dc.subject Ethiopian highlands en
dc.title Climatic change in northern Ethiopia during the past 17,000 years: a diatom and stable isotope record from Lake Ashenge en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.identifier.doi http://dx.doi.org/10.1016/j.palaeo.2009.05.003
dc.contributor.institution Institute of Geography & Earth Sciences en
dc.contributor.institution Quaternary Environmental Change Group en
dc.description.status Peer reviewed en


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