Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorAnderson, Jacob T. H.-
dc.contributor.authorFujioka, Toshiyuki-
dc.contributor.authorFink, David-
dc.contributor.authorHidy, Alan J.-
dc.contributor.authorWilson, Gary S.-
dc.contributor.authorWilcken, Klaus-
dc.contributor.authorAbramov, Andrey-
dc.contributor.authorDemidov, Nikita-
dc.identifier.citationCopernicus GmbH, 2023 [Preprint]es_ES
dc.description.abstractDuring the interglacial and interstadials of Marine Isotope Stage 5 (MIS 5e, 5c, 5a), outlet and alpine glaciers in the Dry Valleys region, Antarctica, appear to have advanced in response to increased precipitation from enhanced open ocean conditions in the Ross Sea. We provide further evidence of this antiphase behaviour through retreat of a peripheral lobe of Taylor Glacier in Pearse Valley, a region that was glaciated during MIS 5. We measured cosmogenic 10Be and 26Al in three granite cobbles from thin, patchy drift (Taylor 2 Drift) in Pearse Valley to constrain the timing of retreat of Taylor Glacier. Assuming simple continuous exposure, our minimum, zero erosion, exposure ages suggest Taylor Glacier partially retreated from Pearse Valley no later than 65–74 ka. Timing of retreat after 65 ka and until the Last Glacial Maximum (LGM) when Taylor Glacier was at a minimum position, remains unresolved. The depositional history of permafrost sediments buried below Taylor 2 Drift in Pearse Valley was obtained from 10Be and 26Al depth profiles to ~3 metres in permafrost in proximity to the cobble sampling sites. Depth profile modelling gives a depositional age for near-surface (< 1.65 m) permafrost at Pearse Valley of 180 ka +20/−40 ka, implying deposition of permafrost sediments predate MIS 5 advances of Taylor Glacier. Depth profile modelling of deeper permafrost sediments (> 2.09 m) indicates a depositional age of > 180 ka. The cobble and permafrost ages reveal Taylor Glacier advances during MIS 5 were non-erosive or mildly erosive, preserving the underlying permafrost sediments and peppering boulders and cobbles upon an older, relict surface. Our results are consistent with U/Th ages from central Taylor Valley, and suggest changes in moisture delivery over Taylor Dome during MIS 5e, 5c and 5a appear to be associated with the extent of the Ross Ice Shelf and sea ice in the Ross Sea. At a coastal, lower elevation site in neighbouring Lower Wright Valley, 10Be and 26Al depth profiles from a second permafrost core exhibit near-constant concentrations with depth, and indicate the sediments are either vertically mixed after deposition, or are sufficiently young and post-depositional nuclide production is negligible relative to inheritance. 26Al/10Be concentration ratios for both depth profiles range between 4.0 and 5.2 and are all lower than the nominal surface production rate ratio of 6.75 indicating that prior to deposition, these sediments experienced a complex exposure-burial history. Assuming a single cycle exposure-burial scenario, the observed 26Al/10Be ratios are equivalent to a total minimum exposure-burial history of ~1.2 Ma. Our new data corroborates antiphase behaviour between outlet and alpine glaciers in the Dry Valleys region and ice extent in the Ross Sea. We suggest a causal relationship of cold-based glacier advance and retreat that is controlled by an increase in moisture availability during retreat of sea ice and perhaps the Ross Ice Shelf, and conversely, a decrease during times of sea ice and Ross Ice Shelf expansion in the Ross Sea.es_ES
dc.description.sponsorshipThis research was supported by NZARI (RFP 2014-1), and ANSTO Portal grants 12215 and 12260 and an AINSE Postgraduate Research Award. JTHA was supported by a Sir Robin Irvine Scholarship, and a University of Otago departmental award. AA and ND were partially supported by the Russian Antarctic Expedition. We acknowledge the financial support from the Australian Government for the Centre for Accelerator Science at ANSTO through the National Collaborative Research Infrastructure Strategy (NCRIS). Prepared in part by LLNL under Contract DE-AC52-07NA27344; LDRD grant 19-LW-036. This is LLNL-JRNL-842669.es_ES
dc.rightsAttribution 4.0 International (CC BY 4.0)*
dc.titleAntiphase dynamics between cold-based glaciers in the Antarctic Dry Valleys region and ice extent in the Ross Sea during MIS 5es_ES
Appears in Collections:Geocronología y Geología

This item is licensed under a Creative Commons License Creative Commons