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dc.contributor.authorFox, Beth R.S.en_NZ
dc.contributor.authorD'Andrea, W.J.en_NZ
dc.contributor.authorWilson, G.S.en_NZ
dc.contributor.authorLee, D.E.en_NZ
dc.contributor.authorWartho, J.-A.en_NZ
dc.date.accessioned2017-11-08T22:26:33Z
dc.date.available2017en_NZ
dc.date.available2017-11-08T22:26:33Z
dc.date.issued2017en_NZ
dc.identifier.citationFox, B. R. S., D’Andrea, W. J., Wilson, G. S., Lee, D. E., & Wartho, J.-A. (2017). Interaction of polar and tropical influences in the mid-latitudes of the Southern Hemisphere during the Mi-1 deglaciation. Global and Planetary Change, 155, 109–120. https://doi.org/10.1016/j.gloplacha.2017.06.008en
dc.identifier.issn0921-8181en_NZ
dc.identifier.urihttp://hdl.handle.net/10289/11470
dc.description.abstractIt is well-known from geologic archives that Pleistocene and Holocene climate is characterised by cyclical variation on a wide range of timescales, and that these cycles of variation interact in complex ways. However, it is rarely possible to reconstruct sub-precessional (< 20 kyr) climate variations for periods predating the oldest ice-core records (c. 800 ka). Here we present an investigation of orbital to potentially sub-precessional cyclicity from an annually resolved lake sediment core dated to a 100-kyr period in the earliest Miocene (23.03–22.93 Ma) and spanning a period of major Antarctic deglaciation associated with the second half of the Mi-1 event. Principal component analysis (PCA) of sediment bulk density, magnetic susceptibility (MS), and CIELAB L* and b* with a resolution of ~10 years indicates two major environmental processes governing the physical properties records, which we interpret as changes in wind strength and changes in precipitation. Spectral analysis of the principal components indicates that both processes are strongly influenced by obliquity (41 kyr). We interpret this 41-kyr cycle in wind strength and precipitation as related to the changing position and strength of the Southern Hemisphere westerly winds. Precipitation is also influenced by an 11-kyr cycle. The 11-kyr periodicity is potentially related to orbital cyclicity, representing the equatorial semi-precessional maximum insolation cycle. This semi-precession cycle has been identified in a number of records from the Pleistocene and Holocene and has recently been suggested to indicate that insolation in low-latitude regions may be an important driver of millennial-scale climate response to orbital forcing (Feretti et al., 2015). This is the first time this cycle has been identified in a mid-latitude Southern Hemisphere climate archive, as well as the first identification in pre-Pleistocene records. The 11-kyr cycle appears at around 23.01 Ma, which coincides with the initiation of a major phase of Antarctic deglaciation, and strengthens during the subsequent period of rapid ice decay. This pattern suggests that the westerly winds may have expanded north of 50°S at the height of Mi-1, excluding tropical influence from the Foulden Maar site, and subsequently contracted polewards in tandem with warming deep-sea temperatures and Antarctic deglaciation, allowing the advection of tropical waters further south.
dc.language.isoenen_NZ
dc.publisherElsevieren_NZ
dc.rightsThis is an author’s accepted version of an article published in the journal: Global and Planetary Change. © 2017 Elsevier.
dc.subjectScience & Technologyen_NZ
dc.subjectPhysical Sciencesen_NZ
dc.subjectGeography, Physicalen_NZ
dc.subjectGeosciences, Multidisciplinaryen_NZ
dc.subjectPhysical Geographyen_NZ
dc.subjectGeologyen_NZ
dc.subjectSouthern Hemisphere palaeoclimateen_NZ
dc.subjectEarly Mioceneen_NZ
dc.subjectMi-1 eventen_NZ
dc.subjectOrbital forcingen_NZ
dc.subjectSemi-precessionen_NZ
dc.subjectWesterly windsen_NZ
dc.subjectNEW-ZEALANDen_NZ
dc.subjectEARLY MIOCENEen_NZ
dc.subjectMAAR LAKEen_NZ
dc.subjectICE-SHEETen_NZ
dc.subjectCLIMATE VARIABILITYen_NZ
dc.subjectNORTHEASTERN CHINAen_NZ
dc.subjectLATE HOLOCENEen_NZ
dc.subjectFOULDEN MAARen_NZ
dc.subjectCARBON-CYCLEen_NZ
dc.subjectOLIGOCENEen_NZ
dc.subjectSouthern Hemisphere palaeoclimate
dc.subjectEarly Miocene
dc.subjectMi-1 event
dc.subjectOrbital forcing
dc.subjectSemi-precession
dc.subjectWesterly winds
dc.titleInteraction of polar and tropical influences in the mid-latitudes of the Southern Hemisphere during the Mi-1 deglaciationen_NZ
dc.typeJournal Article
dc.identifier.doi10.1016/j.gloplacha.2017.06.008en_NZ
dc.relation.isPartOfGlobal and Planetary Changeen_NZ
pubs.begin-page109
pubs.elements-id200408
pubs.end-page120
pubs.organisational-group/Waikato
pubs.organisational-group/Waikato/2018 PBRF
pubs.organisational-group/Waikato/FSEN
pubs.organisational-group/Waikato/FSEN/2018 PBRF - FSEN
pubs.organisational-group/Waikato/FSEN/School of Science
pubs.organisational-group/Waikato/FSEN/School of Science/2018 PBRF - School of Science
pubs.publication-statusPublisheden_NZ
pubs.volume155en_NZ
dc.identifier.eissn1872-6364en_NZ


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