Southward shift of the Intertropical Convergence Zone due to Northern Hemisphere cooling at the Oligocene-Miocene boundary SCIE SCOPUS

DC Field Value Language Hyeong, Kiseong - Lee, Jongmin - Seo, Inah - Lee, Mi Jung - Yoo, Chan Min - Khim, Boo-Keun - 2020-04-20T04:40:17Z - 2020-04-20T04:40:17Z - 2020-01-28 - 2014-08 -
dc.identifier.issn 0091-7613 -
dc.identifier.uri -
dc.description.abstract The Mi-1 glaciation (ca. 23 Ma), which marks the Oligocene-Miocene boundary, was an aberrant cooling event that led to a build-up of the Antarctic ice sheet, which reached the near-modern volume (or greater) from its ephemeral or partial existence. An increase of similar to 1% in the delta O-18 of benthic foraminifera during this interval has been attributed to the development of Antarctic ice sheets and deep-water cooling. Without definitive evidence, Northern Hemisphere (NH) glaciation has not been a material consideration for the delta O-18 increase. Here we investigate the interhemispheric temperature contrast during Mi-1, with the movement of the Intertropical Convergence Zone (ITCZ) at a site (10 degrees 31'N) in the East Pacific (Integrated Ocean Drilling Program Site U1333), to understand NH cooling and the possibility of NH glaciation. The measured Nd-143/Nd-144, Sr-87/Sr-86, and clay mineral compositions of eolian dust fractions indicate unequivocally the deposition of Asian dust during Mi-1, and of Central American and South American dust before and after Mi-1. This is attributed to the southward displacement of the ITCZ over Site U1333 during Mi-1. The ITCZ shifts toward the warmer hemisphere. Thus our results suggest that the cooling during Mi-1 was more significant in the NH than in the Southern Hemisphere, which underwent a sudden expansion of continental ice sheets. Our data call for a forcing mechanism to drive significant NH cooling during this episode. Based on the available data, we propose that the widespread growth of NH ice sheets and/or changes in the production of North Atlantic-origin deep water could be possible causes of the NH cooling at that time. -
dc.description.uri 1 -
dc.language English -
dc.subject CARBON-CYCLE -
dc.subject CLIMATE -
dc.subject SEDIMENT -
dc.subject SEA -
dc.subject VARIABILITY -
dc.subject DUST -
dc.title Southward shift of the Intertropical Convergence Zone due to Northern Hemisphere cooling at the Oligocene-Miocene boundary -
dc.type Article -
dc.citation.endPage 670 -
dc.citation.startPage 667 -
dc.citation.title GEOLOGY -
dc.citation.volume 42 -
dc.citation.number 8 -
dc.identifier.bibliographicCitation GEOLOGY, v.42, no.8, pp.667 - 670 -
dc.identifier.doi 10.1130/G35664.1 -
dc.identifier.scopusid 2-s2.0-84905157307 -
dc.identifier.wosid 000339961600007 -
dc.type.docType Article -
dc.description.journalClass 1 -
dc.subject.keywordPlus ANTARCTIC ICE-SHEET -
dc.subject.keywordPlus CARBON-CYCLE -
dc.subject.keywordPlus CLIMATE -
dc.subject.keywordPlus SEDIMENT -
dc.subject.keywordPlus SEA -
dc.subject.keywordPlus VARIABILITY -
dc.subject.keywordPlus DUST -
dc.relation.journalWebOfScienceCategory Geology -
dc.description.journalRegisteredClass scie -
dc.description.journalRegisteredClass scopus -
dc.relation.journalResearchArea Geology -
Appears in Collections:
Marine Resources Research Division > Global Ocean Research Center > 1. Journal Articles
Marine Resources Research Division > Deep-sea Mineral Resources Research Center > 1. Journal Articles
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