Evidence for Holocene ice sheet history from geomorphology, cosmogenic isotopes, and bird vomit, East Antarctica.

2021 ◽  
Author(s):  
Mike Bentley ◽  
Dominic Hodgson ◽  
Andy Hein ◽  
Steve Binnie ◽  
Steve Moreton
Keyword(s):  
Ice Sheet ◽  
Weddell Sea ◽  
East Antarctica ◽  
Antarctic Ice Sheet ◽  
Cosmogenic Isotopes ◽  
Narrow Zone ◽  
History Of ◽  
Dronning Maud Land ◽  
Fossil Bird

<p>The post-LGM thinning history of the East Antarctic Ice Sheet is not yet well constrained. Here we report some integrated observations and analyses that constrain the ice sheet thinning history in Western Dronning Maud Land and Coats Land, adjacent to the easternmost Weddell Sea, which is a key area of uncertainty in ice sheet reconstructions. Geomorphological observations show a distinct series of weathering zones with fresh erratics only found in a relatively narrow zone above the present ice sheet margin. We report cosmogenic surface exposure dates of erratics in the different weathering zones, using <sup>10</sup>Be and in situ <sup>14</sup>C. We further report a large number of radiocarbon ages on sub-fossil bird vomit (regurgitated proventricular stomach oil, sometimes termed ‘mumiyo’) from nesting snow petrels (Pagodroma nivea) which record periods of ice sheet absence. Together these analyses allow us to determine a more tightly constrained thinning history of the ice sheet in this sector. We discuss the implications of this thinning history for geologically-based ice sheet reconstructions and for ice sheet models.</p>

Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: Constraints on past ice volume change

Geology ◽  
2010 ◽  
Vol 38 (5) ◽  
pp. 411-414 ◽  
Author(s):  
Michael J. Bentley ◽  
Christopher J. Fogwill ◽  
Anne M. Le Brocq ◽  
Alun L. Hubbard ◽  
David E. Sugden ◽  
...  
Keyword(s):  
Volume Change ◽  
Ice Sheet ◽  
Weddell Sea ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
Ice Volume ◽  
West Antarctic ◽  
History Of

scholarly journals The Weddell Sea region: an important precipitation channel to the interior of the Antarctic ice sheet as revealed by glaciochemical investigation of surface snow along the longest trans-Antarctic route

1999 ◽  
Vol 29 ◽  
pp. 55-60 ◽  
Author(s):  
Qin Dahe ◽  
Paul A. Mayewski ◽  
Ren Jiawen ◽  
Xiao Cunde ◽  
Sun Junying
Keyword(s):  
Ice Sheet ◽  
Weddell Sea ◽  
Sea Salt ◽  
East Antarctica ◽  
Antarctic Ice Sheet ◽  
Air Masses ◽  
Antarctic Plateau ◽  
Salt Ions ◽  
Surface Snow ◽  
The Antarctic

AbstractGlaciochemical analysis of surface snow samples, collected along a profile crossing the Antarctic ice sheet from the Larsen Ice Shelf, Antarctic Peninsula, via the Antarctic Plateau through South Pole, Vostok and Komsomolskaya to Mirny station (at the east margin of East Antarctica), shows that the Weddell Sea region is an important channel for air masses to the high plateau of the Antarctic ice sheet (>2000 m a.s.l.). This opinion is supported by the following. (1) The fluxes of sea-salt ions such as Na+, Mg2 + and CF display a decreasing trend from the west to the east of interior Antarctica. In |eneral, as sea-salt aerosols are injected into the atmosphere over the Antarctic ice sheet from the Weddell Sea, large aerosols tend to decrease. For the inland plateau, few large particles of sea-salt aerosol reach the area, and the sea-salt concentration levels are low (2) The high altitude of the East Antarctic plateau, as well as the polar cold high-pressure system, obstruct the intrusive air masses mainly from the South Indian Ocean sector. (3) For the coastal regions of the East Antarctic ice sheet, the elevation rises to 2000 m over a distance from several to several tens of km. High concentrations of sea salt exist in snow in East Antarctica but are limited to a narrow coastal zone. (4) Fluxes of calcium and non-sea-salt sulfate in snow from the interior plateau do not display an eastward-decreasing trend. Since calcium is mainly derived from crustal sources, and nssSO42- is a secondary aerosol, this again confirms that the eastward-declining tendency of sea-salt ions indicates the transfer direction of precipitation vapor.

scholarly journals Deglacial history of the West Antarctic Ice Sheet in the Weddell Sea embayment: Constraints on past ice volume change: REPLY

Geology ◽  
2011 ◽  
Vol 39 (5) ◽  
pp. e240-e240 ◽  
Author(s):  
Michael J. Bentley ◽  
David E. Sugden ◽  
Christopher J. Fogwill ◽  
Anne M. Le Brocq ◽  
Alun L. Hubbard ◽  
...  
Keyword(s):  
Volume Change ◽  
Ice Sheet ◽  
Weddell Sea ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
Ice Volume ◽  
West Antarctic ◽  
History Of

No significant ice-sheet expansion beyond present ice margins during the past 4500 yr at Rauer Group, East Antarctica

2010 ◽  
Vol 74 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Sonja Berg ◽  
Bernd Wagner ◽  
Duanne A. White ◽  
Martin Melles
Keyword(s):  
Sediment Core ◽  
Radiocarbon Dating ◽  
Ice Sheet ◽  
East Antarctica ◽  
Antarctic Ice Sheet ◽  
The Holocene ◽  
The Core ◽  
The Past ◽  
Field Evidence ◽  
History Of

AbstractThe history of glacial advances and retreats of the East Antarctic ice sheet during the Holocene is not well-known, due to limited field evidence in both the marine and terrestrial realm. A 257-cm-long sediment core was recovered from a marine inlet in the Rauer Group, East Antarctica, 1.8 km in front of the present ice-sheet margin. Radiocarbon dating and lithological characteristics reveal that the core comprises a complete marine record since 4500 yr. A significant ice-sheet expansion beyond present ice margins therefore did not occur during this period.

scholarly journals Age stratigraphy in the East Antarctic Ice Sheet inferred from radio echo sounding horizons

2018 ◽  
Author(s):  
Anna Winter ◽  
Daniel Steinhage ◽  
Timothy T. Creyts ◽  
Thomas Kleiner ◽  
Olaf Eisen
Keyword(s):  
Ice Sheet ◽  
Ice Cores ◽  
Radar Data ◽  
East Antarctica ◽  
Airborne Radar ◽  
Antarctic Ice Sheet ◽  
Radio Echo Sounding ◽  
Flow Features ◽  
Dronning Maud Land ◽  
East Antarctic Ice Sheet

Abstract. The East Antarctic Ice Sheet contains a wealth of information that can be extracted from its internal architecture such as distribution of age, past flow features and surface and basal properties. Airborne radar surveys can sample this stratigraphic archive across broad areas. Here, we identify and trace key horizons across several radar surveys to obtain the stratigraphic information. We transfer the age-depth scales from ice cores to intersecting radar data. We then propagate these age scales across the ice sheet using the high fidelity continuity of the radar horizons. In Dronning Maud Land, including Dome Fuji, we mapped isochrones with ages of 38 ka and 74 ka. In the central region of East Antarctica around Dome Concordia, Vostok, and Dome Argus, we use isochrone ages of 38 ka, 48 ka, 90 ka, and 161 ka. Taking together both regions, we provide isochrone depths traced along a combined profile length of more than 40,000 km and discuss uncertainties of the obtained stratigraphy, as well as factors important to consider for further expansion. This dataset the most extensive distribution of internal horizons in East Antarctica to date. The isochrone depths are available on PANGAEA: https://doi.pangaea.de/10.1594/PANGAEA.895528.

scholarly journals Deep ice-core drilling at Dome Fuji and glaciological studies in east Dronning Maud Land, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 333-337 ◽  
Author(s):  
Dome-F Deep Coring Group
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
Field Observations ◽  
Antarctic Ice Sheet ◽  
Core Drilling ◽  
Dronning Maud Land ◽  
Tephra Layers ◽  
The Antarctic ◽  
Comprehensive Study

The Dome Fuji Project is a comprehensive study of present and past glaeiological/climatological features of the Antarctic ice sheet in east Dronning Maud Land. Field observations on a 100U km traverse route from the coast to Dome Fuji slum changes in various glaciological parameters with surface elevation and distance from the coast. Deep ice-core drilling at Dome Fuji was started in August 1995 and reached a depth of 2503.52 m in December 1996. in situ core analyses revealed 25 visible tephra layers and a number of distinct cloudy bands in the ice.

scholarly journals Age stratigraphy in the East Antarctic Ice Sheet inferred from radio-echo sounding horizons

2019 ◽  
Vol 11 (3) ◽  
pp. 1069-1081 ◽  
Author(s):  
Anna Winter ◽  
Daniel Steinhage ◽  
Timothy T. Creyts ◽  
Thomas Kleiner ◽  
Olaf Eisen
Keyword(s):  
Ice Sheet ◽  
Ice Cores ◽  
Radar Data ◽  
East Antarctica ◽  
Data Set ◽  
Antarctic Ice Sheet ◽  
Radio Echo Sounding ◽  
Flow Features ◽  
Dronning Maud Land ◽  
East Antarctic Ice Sheet

Abstract. The East Antarctic Ice Sheet contains a wealth of information that can be extracted from its internal architecture such as distribution of age, past flow features, and surface and basal properties. Airborne radar surveys can sample this stratigraphic archive across broad areas. Here, we identify and trace key horizons across several radar surveys to obtain the stratigraphic information. We transfer the age–depth scales from ice cores to intersecting radar data. We then propagate these age scales across the ice sheet using the high fidelity continuity of the radar horizons. In Dronning Maud Land, including Dome Fuji, we mapped isochrones with ages of 38 and 74 ka. In the central region of East Antarctica around Dome Concordia, Vostok and Dome Argus, we use isochrone ages of 38, 48, 90 and 161 ka. Taking together both regions, we provide isochrone depths traced along a combined profile length of more than 40 000 km and discuss uncertainties of the obtained stratigraphy, as well as factors important to consider for further expansion. This data set is the most extensive distribution of internal horizons in East Antarctica to date. The isochrone depths presented in this study are available on PANGAEA (https://doi.org/10.1594/PANGAEA.895528; Winter et al., 2018).

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