Pleistocene glacial history of the New Zealand subantarctic islands
<p>The New Zealand subantarctic islands of Auckland and Campbell, situated between the subtropical front and the Antarctic Convergence in the Pacific sector of the Southern Ocean, provide valuable terrestrial records from a globally important climatic region. Whilst the islands show clear evid...
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| Language: | English |
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Copernicus Publications
2019-03-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/15/423/2019/cp-15-423-2019.pdf |
| _version_ | 1818838617513000960 |
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| author | E. Rainsley C. S. M. Turney C. S. M. Turney N. R. Golledge N. R. Golledge J. M. Wilmshurst J. M. Wilmshurst M. S. McGlone A. G. Hogg A. G. Hogg B. Li B. Li Z. A. Thomas Z. A. Thomas R. Roberts R. Roberts R. T. Jones R. T. Jones J. G. Palmer J. G. Palmer V. Flett G. de Wet D. K. Hutchinson M. J. Lipson P. Fenwick B. R. Hines U. Binetti C. J. Fogwill C. J. Fogwill |
| author_facet | E. Rainsley C. S. M. Turney C. S. M. Turney N. R. Golledge N. R. Golledge J. M. Wilmshurst J. M. Wilmshurst M. S. McGlone A. G. Hogg A. G. Hogg B. Li B. Li Z. A. Thomas Z. A. Thomas R. Roberts R. Roberts R. T. Jones R. T. Jones J. G. Palmer J. G. Palmer V. Flett G. de Wet D. K. Hutchinson M. J. Lipson P. Fenwick B. R. Hines U. Binetti C. J. Fogwill C. J. Fogwill |
| author_sort | E. Rainsley |
| collection | DOAJ |
| description | <p>The New Zealand subantarctic islands of Auckland and Campbell,
situated between the subtropical front and the Antarctic Convergence in the
Pacific sector of the Southern Ocean, provide valuable terrestrial records
from a globally important climatic region. Whilst the islands show clear
evidence of past glaciation, the timing and mechanisms behind Pleistocene
environmental and climate changes remain uncertain. Here we present a
multidisciplinary study of the islands – including marine and terrestrial
geomorphological surveys, extensive analyses of sedimentary sequences, a
comprehensive dating programme, and glacier flow line modelling – to
investigate multiple phases of glaciation across the islands. We find
evidence that the Auckland Islands hosted a small ice cap
384 000 <span class="inline-formula">±</span> 26 000 years ago (<span class="inline-formula">384±26</span> ka), most likely during
Marine Isotope Stage 10, a period when the subtropical front was reportedly
north of its present-day latitude by several degrees, and consistent with
hemispheric-wide glacial expansion. Flow line modelling constrained by field
evidence suggests a more restricted glacial period prior to the LGM that
formed substantial valley glaciers on the Campbell and Auckland Islands around
72–62 ka. Despite previous interpretations that suggest the maximum glacial
extent occurred in the form of valley glaciation at the Last Glacial Maximum
(LGM; <span class="inline-formula">∼21</span> ka), our combined approach suggests minimal LGM
glaciation across the New Zealand subantarctic islands and that no glaciers
were present during the Antarctic Cold Reversal (ACR; <span class="inline-formula">∼15</span>–13 ka).
Instead, modelling implies that despite a regional mean annual air
temperature depression of <span class="inline-formula">∼5</span> <span class="inline-formula"><sup>∘</sup></span>C during the LGM, a combination
of high seasonality and low precipitation left the islands incapable of
sustaining significant glaciation. We suggest that northwards expansion of
winter sea ice during the LGM and subsequent ACR led to precipitation
starvation across the middle to high latitudes of the Southern Ocean, resulting
in restricted glaciation of the subantarctic islands.</p> |
| first_indexed | 2024-12-19T03:41:15Z |
| format | Article |
| id | doaj.art-d8c6e95f84434590bcdc5e1c28a43621 |
| institution | Directory Open Access Journal |
| issn | 1814-9324 1814-9332 |
| language | English |
| last_indexed | 2024-12-19T03:41:15Z |
| publishDate | 2019-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Climate of the Past |
| spelling | doaj.art-d8c6e95f84434590bcdc5e1c28a436212022-12-21T20:37:13ZengCopernicus PublicationsClimate of the Past1814-93241814-93322019-03-011542344810.5194/cp-15-423-2019Pleistocene glacial history of the New Zealand subantarctic islandsE. Rainsley0C. S. M. Turney1C. S. M. Turney2N. R. Golledge3N. R. Golledge4J. M. Wilmshurst5J. M. Wilmshurst6M. S. McGlone7A. G. Hogg8A. G. Hogg9B. Li10B. Li11Z. A. Thomas12Z. A. Thomas13R. Roberts14R. Roberts15R. T. Jones16R. T. Jones17J. G. Palmer18J. G. Palmer19V. Flett20G. de Wet21D. K. Hutchinson22M. J. Lipson23P. Fenwick24B. R. Hines25U. Binetti26C. J. Fogwill27C. J. Fogwill28ICELAB, School of Geography, Geology and the Environment, University of Keele, Staffordshire, ST5 5BG, UKPalaeontology, Geobiology and Earth Archives Research Centre (PANGEA), School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, AustraliaAustralian Research Council Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of New South Wales, NSW 2052, AustraliaAntarctic Research Centre, Victoria University of Wellington, Wellington 6140, New ZealandGNS Science, Avalon, Lower Hutt 5011, New ZealandLong Term Ecology Laboratory, Landcare Research, Lincoln, New ZealandSchool of Environment, University of Auckland, Private Bag 92019, Auckland 1142, New ZealandLong Term Ecology Laboratory, Landcare Research, Lincoln, New ZealandWaikato Radiocarbon Laboratory, University of Waikato, Private Bag 3105, Hamilton, New ZealandAustralian Research Council (ARC) Centre of Excellence for Australian Biodiversity and Heritage, University of Waikato, Hamilton 3240, New ZealandCentre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, AustraliaAustralian Research Council (ARC) Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, NSW 2522, AustraliaPalaeontology, Geobiology and Earth Archives Research Centre (PANGEA), School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, AustraliaAustralian Research Council Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of New South Wales, NSW 2052, AustraliaCentre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, AustraliaAustralian Research Council (ARC) Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, NSW 2522, AustraliaDepartment of Geography, University of Exeter, Exeter EX4 4RJ, UKdeceasedPalaeontology, Geobiology and Earth Archives Research Centre (PANGEA), School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, AustraliaAustralian Research Council Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of New South Wales, NSW 2052, AustraliaSchool of the Environment, University of Dundee, Nethergate DD1 4HN, UKInstitute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USABolin Centre for Climate Research and Department of Geological Sciences, Stockholm University, Stockholm, SwedenARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, AustraliaGondwana Tree-Ring Laboratory, P.O. Box 14, Little River, Canterbury 7546, New ZealandSchool of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New ZealandCentre for Ocean and Atmospheric Studies, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UKICELAB, School of Geography, Geology and the Environment, University of Keele, Staffordshire, ST5 5BG, UKPalaeontology, Geobiology and Earth Archives Research Centre (PANGEA), School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia<p>The New Zealand subantarctic islands of Auckland and Campbell, situated between the subtropical front and the Antarctic Convergence in the Pacific sector of the Southern Ocean, provide valuable terrestrial records from a globally important climatic region. Whilst the islands show clear evidence of past glaciation, the timing and mechanisms behind Pleistocene environmental and climate changes remain uncertain. Here we present a multidisciplinary study of the islands – including marine and terrestrial geomorphological surveys, extensive analyses of sedimentary sequences, a comprehensive dating programme, and glacier flow line modelling – to investigate multiple phases of glaciation across the islands. We find evidence that the Auckland Islands hosted a small ice cap 384 000 <span class="inline-formula">±</span> 26 000 years ago (<span class="inline-formula">384±26</span> ka), most likely during Marine Isotope Stage 10, a period when the subtropical front was reportedly north of its present-day latitude by several degrees, and consistent with hemispheric-wide glacial expansion. Flow line modelling constrained by field evidence suggests a more restricted glacial period prior to the LGM that formed substantial valley glaciers on the Campbell and Auckland Islands around 72–62 ka. Despite previous interpretations that suggest the maximum glacial extent occurred in the form of valley glaciation at the Last Glacial Maximum (LGM; <span class="inline-formula">∼21</span> ka), our combined approach suggests minimal LGM glaciation across the New Zealand subantarctic islands and that no glaciers were present during the Antarctic Cold Reversal (ACR; <span class="inline-formula">∼15</span>–13 ka). Instead, modelling implies that despite a regional mean annual air temperature depression of <span class="inline-formula">∼5</span> <span class="inline-formula"><sup>∘</sup></span>C during the LGM, a combination of high seasonality and low precipitation left the islands incapable of sustaining significant glaciation. We suggest that northwards expansion of winter sea ice during the LGM and subsequent ACR led to precipitation starvation across the middle to high latitudes of the Southern Ocean, resulting in restricted glaciation of the subantarctic islands.</p>https://www.clim-past.net/15/423/2019/cp-15-423-2019.pdf |
| spellingShingle | E. Rainsley C. S. M. Turney C. S. M. Turney N. R. Golledge N. R. Golledge J. M. Wilmshurst J. M. Wilmshurst M. S. McGlone A. G. Hogg A. G. Hogg B. Li B. Li Z. A. Thomas Z. A. Thomas R. Roberts R. Roberts R. T. Jones R. T. Jones J. G. Palmer J. G. Palmer V. Flett G. de Wet D. K. Hutchinson M. J. Lipson P. Fenwick B. R. Hines U. Binetti C. J. Fogwill C. J. Fogwill Pleistocene glacial history of the New Zealand subantarctic islands Climate of the Past |
| title | Pleistocene glacial history of the New Zealand subantarctic islands |
| title_full | Pleistocene glacial history of the New Zealand subantarctic islands |
| title_fullStr | Pleistocene glacial history of the New Zealand subantarctic islands |
| title_full_unstemmed | Pleistocene glacial history of the New Zealand subantarctic islands |
| title_short | Pleistocene glacial history of the New Zealand subantarctic islands |
| title_sort | pleistocene glacial history of the new zealand subantarctic islands |
| url | https://www.clim-past.net/15/423/2019/cp-15-423-2019.pdf |
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