Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum
The AND-2A drill hole (ANDRILL [Antarctic Geological Drilling Program] Southern McMurdo Sound Project), ∼10 km from the East Antarctica coastline, records nearly 6 m.y. of sedimentation across the Miocene climatic optimum at a high-latitude site. Sedimentological studies of bedforms and particle siz...
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ftopenaccessrep:oai:zenodo.org:105155 2023-10-25T01:32:07+02:00 Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum Sandra Passchier Fabio Florindo Candice J. Falk 2012-12-13 https://www.openaccessrepository.it/record/105155 https://doi.org/10.1130/ges00840.1 eng eng url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/105155 doi:10.1130/ges00840.1 info:eu-repo/semantics/openAccess NEANIAS Atmospheric Research Community Digital Humanities and Cultural Heritage Stratigraphy Geology info:eu-repo/semantics/article publication-article 2012 ftopenaccessrep https://doi.org/10.1130/ges00840.1 2023-09-26T22:17:36Z The AND-2A drill hole (ANDRILL [Antarctic Geological Drilling Program] Southern McMurdo Sound Project), ∼10 km from the East Antarctica coastline, records nearly 6 m.y. of sedimentation across the Miocene climatic optimum at a high-latitude site. Sedimentological studies of bedforms and particle size distributions indicate that the paleoenvironment was strongly affected by waves and currents, consistent with deposition in a glacially influenced neritic environment. We document abrupt shifts in mud percent within glacial-interglacial cycles ca. 17.8 Ma and between ca. 16.7 and 15.7 Ma that we attribute to the hydrodynamic effects of wave stirring tied to episodes of ice growth and decay. Although wave climate and geodynamic forcing of the paleobathymetry simultaneously affect wave stirring on a high-latitude shelf, both are ultimately controlled by the size of the ice sheet. The mud percent record displays cyclicity at short-eccentricity time scales (94–99 k.y.) and, unexpectedly, ice retreat phases interpreted from the particle size record coincide with eccentricity minima. We attribute the eccentricity-paced ice retreat phases during the late Early Miocene polythermal glacial conditions and the cool orbital parameters to marine ice sheet instability in response to changes in ocean circulation and heat transport. The particle size record of the AND-2A core provides unique near-field evidence for orbitally paced changes in high-latitude climate and ice volume during the Miocene climatic optimum and important insights into the mechanisms of ice sheet growth and decay in a period of global warmth. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet McMurdo Sound Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository Antarctic East Antarctica McMurdo Sound Geosphere 9 1 54 62 |
institution |
Open Polar |
collection |
Istituto Nazionale di Fisica Nucleare (INFN): Open Access Repository |
op_collection_id |
ftopenaccessrep |
language |
English |
topic |
NEANIAS Atmospheric Research Community Digital Humanities and Cultural Heritage Stratigraphy Geology |
spellingShingle |
NEANIAS Atmospheric Research Community Digital Humanities and Cultural Heritage Stratigraphy Geology Sandra Passchier Fabio Florindo Candice J. Falk Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
topic_facet |
NEANIAS Atmospheric Research Community Digital Humanities and Cultural Heritage Stratigraphy Geology |
description |
The AND-2A drill hole (ANDRILL [Antarctic Geological Drilling Program] Southern McMurdo Sound Project), ∼10 km from the East Antarctica coastline, records nearly 6 m.y. of sedimentation across the Miocene climatic optimum at a high-latitude site. Sedimentological studies of bedforms and particle size distributions indicate that the paleoenvironment was strongly affected by waves and currents, consistent with deposition in a glacially influenced neritic environment. We document abrupt shifts in mud percent within glacial-interglacial cycles ca. 17.8 Ma and between ca. 16.7 and 15.7 Ma that we attribute to the hydrodynamic effects of wave stirring tied to episodes of ice growth and decay. Although wave climate and geodynamic forcing of the paleobathymetry simultaneously affect wave stirring on a high-latitude shelf, both are ultimately controlled by the size of the ice sheet. The mud percent record displays cyclicity at short-eccentricity time scales (94–99 k.y.) and, unexpectedly, ice retreat phases interpreted from the particle size record coincide with eccentricity minima. We attribute the eccentricity-paced ice retreat phases during the late Early Miocene polythermal glacial conditions and the cool orbital parameters to marine ice sheet instability in response to changes in ocean circulation and heat transport. The particle size record of the AND-2A core provides unique near-field evidence for orbitally paced changes in high-latitude climate and ice volume during the Miocene climatic optimum and important insights into the mechanisms of ice sheet growth and decay in a period of global warmth. |
format |
Article in Journal/Newspaper |
author |
Sandra Passchier Fabio Florindo Candice J. Falk |
author_facet |
Sandra Passchier Fabio Florindo Candice J. Falk |
author_sort |
Sandra Passchier |
title |
Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
title_short |
Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
title_full |
Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
title_fullStr |
Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
title_full_unstemmed |
Orbitally paced shifts in the particle size of Antarctic continental shelf sediments in response to ice dynamics during the Miocene climatic optimum |
title_sort |
orbitally paced shifts in the particle size of antarctic continental shelf sediments in response to ice dynamics during the miocene climatic optimum |
publishDate |
2012 |
url |
https://www.openaccessrepository.it/record/105155 https://doi.org/10.1130/ges00840.1 |
geographic |
Antarctic East Antarctica McMurdo Sound |
geographic_facet |
Antarctic East Antarctica McMurdo Sound |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet McMurdo Sound |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet McMurdo Sound |
op_relation |
url:https://www.openaccessrepository.it/communities/itmirror https://www.openaccessrepository.it/record/105155 doi:10.1130/ges00840.1 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1130/ges00840.1 |
container_title |
Geosphere |
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9 |
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1 |
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54 |
op_container_end_page |
62 |
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1780727693675855872 |