Multiple cosmogenic nuclides document the stability of the East Antarctic Ice Sheet in northern Victoria Land since the Late Miocene (5–7 Ma)

2012 ◽  
Vol 57 ◽  
pp. 85-94 ◽  
Author(s):  
Luigia Di Nicola ◽  
Carlo Baroni ◽  
Stefan Strasky ◽  
Maria Cristina Salvatore ◽  
Christian Schlüchter ◽  
...  
Keyword(s):  
Late Miocene ◽  
Ice Sheet ◽  
Cosmogenic Nuclides ◽  
Antarctic Ice Sheet ◽  
Victoria Land ◽  
The Stability ◽  
East Antarctic Ice Sheet

scholarly journals The East Antarctic Ice Sheet: The Problem of Palaeoglaciological Reconstruction (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 344 ◽  
Author(s):  
V.I. Bardin
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Regional Studies ◽  
Glacial Deposits ◽  
Antarctic Ice Sheet ◽  
Space And Time ◽  
Victoria Land ◽  
East Antarctic Ice Sheet ◽  
Comprehensive Studies

Palaeoglaciological studies, including glaciogeomorphological observations and comprehensive studies of the composition of glacial deposits, undertaken by scientists of a number of countries, enable the major stages in the evolution of glaciation of some regions of East Antarctica to be outlined. In this report, palaeoglaciological reconstructions for certain key territories: Queen Maud Land, Mac. Robertson Land, and Victoria Land are considered. The completeness and reliability of such reconstructions are also discussed. The region of Prince Charles Mountains (Mac. Robertson Land) turned out to be one of the most significant for palaeoglaciology. In this region, the author has discovered and studied glacial deposits of at least six age stages, their formation having taken place during approximately 20 Ma. An attempt is made to compare the results of regional studies and to present the evolution of the development of the whole East Antarctic ice sheet in space and time. Different examples of palaeoglaciological reconstructions of the ice sheet of East Antarctica are presented, the possibilities of different approaches are evaluated practically, and schematic maps of the change in glaciation of East Antarctic regions at different evolutional stages, compiled by the author, are presented for discussion.

scholarly journals East Antarctic Ice Sheet and Southern Ocean Response to Orbital Forcing from Late Miocene to Early Pliocene, Wilkes Land, East Antarctica

2021 ◽  
Author(s):  
◽  
Nikita Anne Turton
Keyword(s):  
Southern Ocean ◽  
Late Miocene ◽  
Ice Sheet ◽  
Orbital Forcing ◽  
Sea Ice Extent ◽  
Antarctic Ice Sheet ◽  
Early Pliocene ◽  
Wilkes Land ◽  
Marine Productivity ◽  
East Antarctic Ice Sheet

<p>Geological and ice sheet models indicate that marine-based sectors of the East Antarctic Ice Sheet (EAIS) were unstable during periods of moderate climatic warmth in the past. While geological records from the Middle to Late Pliocene indicate a dynamic ice sheet, records of ice sheet variability from the comparatively warmer Late Miocene to Early Pliocene are sparse, and there are few direct records of Antarctic ice sheet variability during this time period. Sediment recovered in Integrated Ocean Drilling Program U1361 drill core from the Wilkes Land margin provides a distal but continuous glacially-influenced record of the behaviour of Antarctic Ice Sheets.  This thesis presents marine sedimentological and x-ray fluorescence geochemical datasets in order to assess changes in the dynamic response of the EAIS and Southern Ocean productivity in the Wilkes Land sector during Late Miocene and Early Pliocene to climatic warming and orbital forcing between 6.2 and 4.4 Ma. Two primary lithofacies are identified which can be directly related to glacial–interglacial cycles; enhanced sedimentation during glacials is represented by low-density turbidity flows that occurred in unison with low marine productivity and reduced iceberg rafted debris. Interglacial sediments contain diatomaceous muds with short-lived, large fluxes of iceberg rafted debris preceding a more prolonged phase of enhanced marine productivity. Interglacial sediments coincide with a more mafic source of terrigenous sediment, interfered to be associated with an inland retreat of the ice margin resulting in erosion of lithologies that are currently located beneath the grounded EAIS. Poleward invigoration of the Antarctic Circumpolar Current during glacial–interglacial transitions is proposed to have intensified upwelling, enhancing nutrient availability for marine productivity, and increasing oceanic heat flux at the ice margin acting to erode marine ice sheet grounding lines and triggering retreat.  Spectral analysis of the datasets indicated orbital frequencies are present in the iceberg rafted debris mass accumulation rates at all three Milankovitch frequencies, with a dominant 100 kyr eccentricity driven ice discharge. Prolonged intervals of marine productivity correlate to 100 kyr cyclicity occurring at peaks in obliquity. The response of both ice sheet and biological systems to 100 kyr cyclicity may indicate eccentricity-modulated sea ice extent controls the influx of warm water onto the continental shelf.</p>

scholarly journals East Antarctic Ice Sheet and Southern Ocean Response to Orbital Forcing from Late Miocene to Early Pliocene, Wilkes Land, East Antarctica

2021 ◽  
Author(s):  
◽  
Nikita Anne Turton
Keyword(s):  
Southern Ocean ◽  
Late Miocene ◽  
Ice Sheet ◽  
Orbital Forcing ◽  
Sea Ice Extent ◽  
Antarctic Ice Sheet ◽  
Early Pliocene ◽  
Wilkes Land ◽  
Marine Productivity ◽  
East Antarctic Ice Sheet

<p>Geological and ice sheet models indicate that marine-based sectors of the East Antarctic Ice Sheet (EAIS) were unstable during periods of moderate climatic warmth in the past. While geological records from the Middle to Late Pliocene indicate a dynamic ice sheet, records of ice sheet variability from the comparatively warmer Late Miocene to Early Pliocene are sparse, and there are few direct records of Antarctic ice sheet variability during this time period. Sediment recovered in Integrated Ocean Drilling Program U1361 drill core from the Wilkes Land margin provides a distal but continuous glacially-influenced record of the behaviour of Antarctic Ice Sheets.  This thesis presents marine sedimentological and x-ray fluorescence geochemical datasets in order to assess changes in the dynamic response of the EAIS and Southern Ocean productivity in the Wilkes Land sector during Late Miocene and Early Pliocene to climatic warming and orbital forcing between 6.2 and 4.4 Ma. Two primary lithofacies are identified which can be directly related to glacial–interglacial cycles; enhanced sedimentation during glacials is represented by low-density turbidity flows that occurred in unison with low marine productivity and reduced iceberg rafted debris. Interglacial sediments contain diatomaceous muds with short-lived, large fluxes of iceberg rafted debris preceding a more prolonged phase of enhanced marine productivity. Interglacial sediments coincide with a more mafic source of terrigenous sediment, interfered to be associated with an inland retreat of the ice margin resulting in erosion of lithologies that are currently located beneath the grounded EAIS. Poleward invigoration of the Antarctic Circumpolar Current during glacial–interglacial transitions is proposed to have intensified upwelling, enhancing nutrient availability for marine productivity, and increasing oceanic heat flux at the ice margin acting to erode marine ice sheet grounding lines and triggering retreat.  Spectral analysis of the datasets indicated orbital frequencies are present in the iceberg rafted debris mass accumulation rates at all three Milankovitch frequencies, with a dominant 100 kyr eccentricity driven ice discharge. Prolonged intervals of marine productivity correlate to 100 kyr cyclicity occurring at peaks in obliquity. The response of both ice sheet and biological systems to 100 kyr cyclicity may indicate eccentricity-modulated sea ice extent controls the influx of warm water onto the continental shelf.</p>

Dynamics of Pliocene East Antarctic Ice Sheet from depositional signatures of the Prydz Bay shelf and Trough Mouth Fan

2020 ◽  
Author(s):  
Xiaoxia Huang ◽  
German Leitchenkov ◽  
Anne Bernhardt ◽  
Graeme Eagles ◽  
Karsten Gohl ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Drainage System ◽  
East Antarctica ◽  
Prydz Bay ◽  
Ice Shelf ◽  
Antarctic Ice Sheet ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
The Stability ◽  
East Antarctic Ice Sheet

&lt;p&gt;The Pliocene saw multiple advances and retreats of the ice-sheet margin in East Antarctica. Amery Ice Shelf (AIS) is the largest ice shelf in East Antarctica and also the largest single ice stream draining from the Antarctic Plateau. It buttresses the Lambert Glacier drainage system, and accounts for 14% of the outflow from the East Antarctic Ice Sheet (EAIS). However, evidence for the state of the EAIS during the Pliocene is sparse and difficult to interpret unequivocally. Marine geological-geophysical data collected from the continental shelf in Prydz Bay, Antarctica, including seismic-reflection data, bathymetry, core records from ODP drilling and gravity coring sites, reveal a complex paleo-subglacial drainage system linked to an offshore depositional regime dominated on a trough mouth fan (TMF). Detailed seismic stratigraphic and facies analysis reveals the glacial evolution of Prydz Bay shelf and its TMF, including several glacial expansions across the shelf indicated by erosional surfaces and stratal bodies with chaotic acoustic character. The geometry of seismic sequences suggests that the glaciers and their associated TMF developed after a major episode of shelf and slope erosion during the Pliocene-Pleistocene.&lt;/p&gt;&lt;p&gt;&amp;#160;The shelf in Prydz Bay is dominated by a wide, south-north trending glacially-eroded trough (the Prydz Channel: -500~-1000 m depth) and shallower banks (-500~0 m depth). Well preserved grounding zone wedges areevidenced by prograding foreset deposits. Evidence for erosion of the wedges and/or lineations that extend across their upper surfaces indifferent water depths ranging from 200 m to 800 m imply their formation during multiple glacial stages or cycles. &amp;#160;Stacked erosional surfaces reveal major cross-shelf glacial expansions and the development of deep channel systems (up to -500 m depth) associated with extensive subglacial meltwater in Prydz Bay. These glacial related features provide good constraints for reconstructing the stability of the Pliocene EAIS.&lt;/p&gt;

scholarly journals Some Aspects of the Cenozoic Glaciation of Southern Victoria Land, Antarctica

1983 ◽  
Vol 29 (102) ◽  
pp. 343-349 ◽  
Author(s):  
Howard Brady ◽  
Barrie McKelvey
Keyword(s):  
Middle Miocene ◽  
Ice Sheet ◽  
Basement Complex ◽  
Antarctic Ice Sheet ◽  
Victoria Land ◽  
Transantarctic Mountains ◽  
East Antarctic Ice Sheet

AbstractPalaeoglacial evidence at three sites in southern Victoria Land has been examined to consider the possible uplift of the Transantarctic Mountains through the East Antarctic ice sheet prior to the Middle Miocene. A Cenozoic tillite at Mount Feather and a striated pavement at Mount Brooke pre-date uplift. Another tillite remnant adjacent to Odell Glacier near Mount Brooke post-dates the uplift and is locally derived. This tillite, together with the Mount Feather tillite, has been previously placed in the Sirius Formation, a term that the authors abandon as it covers tillites of varying ages. Basement complex derived clasts in the Mount Feather tillite. previously reported by these authors, could be inherited from the Jurassic Mawson Formation or the Permian Metschel Tillite but they still provide evidence that the Mount Feather tillite was deposited by a regional glaciation.

scholarly journals Surface exposure ages imply multiple low-amplitude Pleistocene variations in East Antarctic Ice Sheet, Ricker Hills, Victoria Land

2008 ◽  
Vol 21 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Stefan Strasky ◽  
Luigia Di Nicola ◽  
Carlo Baroni ◽  
Maria Cristina Salvatore ◽  
Heinrich Baur ◽  
...  
Keyword(s):  
Global Climate ◽  
Ice Sheet ◽  
Early Pleistocene ◽  
Antarctic Ice Sheet ◽  
Global Climate Changes ◽  
Erosion Rates ◽  
Exposure Dating ◽  
Victoria Land ◽  
Exposure Ages ◽  
East Antarctic Ice Sheet

AbstractOne of the major issues in (palaeo-) climatology is the response of Antarctic ice sheets to global climate changes. Antarctic ice volume has varied in the past but the extent and timing of these fluctuations are not well known. In this study, we address the question of amplitude and timing of past Antarctic ice level changes by surface exposure dating using in situ produced cosmogenic nuclides (10Be and 21Ne). The study area lies in the Ricker Hills, a nunatak at the boundary of the East Antarctic Ice Sheet in southern Victoria Land. By determining exposure ages of erratic boulders from glacial drifts we directly date East Antarctic Ice Sheet variations. Erosion-corrected neon and beryllium exposure ages indicate that a major ice advance reaching elevations of about 500 m above present ice levels occurred between 1.125 and 1.375 million years before present. Subsequent ice fluctuations were of lesser extent but timing is difficult as all erratic boulders from related deposits show complex exposure histories. Sample-specific erosion rates were on the order of 20–45 cm Ma-1 for a quartzite and 10–65 cm Ma-1 for a sandstone boulder and imply that the modern cold, arid climate has persisted since at least the early Pleistocene.

scholarly journals Dating late Cenozoic erosional surfaces in Victoria Land, Antarctica, with cosmogenic neon in pyroxenes

2007 ◽  
Vol 20 (1) ◽  
pp. 89-98 ◽  
Author(s):  
P. Oberholzer ◽  
C. Baroni ◽  
M.C. Salvatore ◽  
H. Baur ◽  
R. Wieler
Keyword(s):  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Erosion Rates ◽  
Ice Surface ◽  
Narrow Valley ◽  
Sampling Locations ◽  
Victoria Land ◽  
Minimum Age ◽  
Exposure Ages ◽  
East Antarctic Ice Sheet

AbstractWe present 21Ne exposure ages of erosional glaciogenic rock surfaces on nunataks in northern Victoria Land, Antarctica: i) in the Prince Albert Mountains and ii) near Mesa Range. These nunataks are located directly at the margin of the polar plateau and therefore provide an immediate record of ice volume changes of the East Antarctic Ice Sheet, not biased by ice shelf grounding or narrow valley sections downstream the outlet glaciers. The sampling locations overlook the present ice surface by less than 200 m, but were last covered by ice 3.5 Ma bp (minimum age, not corrected for erosion). This strongly indicates that the ice sheet has not been substantially thicker than today since at least the early Pliocene, which supports the hypothesis of a stable East Antarctic Ice Sheet. First absolute ages are reported for the alpine topography above the erosive trimline that typically marks the upper limit of glacial activity in northern Victoria Land. Unexpectedly low nuclide concentrations suggest that erosion rates on the alpine topography are considerably higher due to the steep slopes than those affecting flat erosional surfaces carrying Antarctic tors.

scholarly journals The East Antarctic Ice Sheet: The Problem of Palaeoglaciological Reconstruction (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 344-344
Author(s):  
V.I. Bardin
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Regional Studies ◽  
Glacial Deposits ◽  
Antarctic Ice Sheet ◽  
Space And Time ◽  
Victoria Land ◽  
East Antarctic Ice Sheet ◽  
Comprehensive Studies

Palaeoglaciological studies, including glaciogeomorphological observations and comprehensive studies of the composition of glacial deposits, undertaken by scientists of a number of countries, enable the major stages in the evolution of glaciation of some regions of East Antarctica to be outlined.In this report, palaeoglaciological reconstructions for certain key territories: Queen Maud Land, Mac. Robertson Land, and Victoria Land are considered. The completeness and reliability of such reconstructions are also discussed.The region of Prince Charles Mountains (Mac. Robertson Land) turned out to be one of the most significant for palaeoglaciology. In this region, the author has discovered and studied glacial deposits of at least six age stages, their formation having taken place during approximately 20 Ma.An attempt is made to compare the results of regional studies and to present the evolution of the development of the whole East Antarctic ice sheet in space and time.Different examples of palaeoglaciological reconstructions of the ice sheet of East Antarctica are presented, the possibilities of different approaches are evaluated practically, and schematic maps of the change in glaciation of East Antarctic regions at different evolutional stages, compiled by the author, are presented for discussion.

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