A testimony of detachment of an inland lake from marine influence during the mid-Holocene in the Vestfold Hills region, East Antarctica

Abstract A 47 cm long sediment core collected from an inland lake of the Vestfold Hills, East Antarctica has been examined to reconstruct the palaeolacustrine environmental changes. The core shows dates at two core intervals of 18-19 cm and 28-29 cm as 5050±98 yrs BP and 5560±96 yrs BP, respectively. The core exhibits a good amount of diatom population throughout the length. Prior to 5560±96 yrs BP, the core shows high abundance of diatom population (>10×107 g-1) along with sufficient salt crystal, which indicates the connection of this lake with the marine environment. From 5560±96 yrs BP to 5050±98 yrs BP the total number diatoms decreased substantially along with the decrease in salt crystal, which indicates the withdrawal of the marine influence from the lake during that period. From 5050±98 yrs BP to Recent, the low number of diatoms and the rare occurrence of salt crystal suggest that the lake remained mostly detached from the sea during the last 5000 yrs.

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Penguin occupation in the Vestfold Hills

Antarctic Science ◽

10.1017/s095410200800165x ◽

2008 ◽

Vol 21 (2) ◽

pp. 131-134 ◽

Cited By ~ 11

Author(s):

Tao Huang ◽

Liguang Sun ◽

Yuhong Wang ◽

Renbin Zhu

Keyword(s):

Sediment Core ◽

Environmental Changes ◽

Sediment Cores ◽

East Antarctica ◽

Before Present ◽

The Holocene ◽

History Of ◽

Vestfold Hills ◽

Free Area ◽

Ornithogenic Sediment

AbstractDuring CHINARE-22 (December 2005–March 2006), we investigated six penguin colonies in the Vestfold Hills, East Antarctica, and collected several penguin ornithogenic sediment cores, samples of fresh guano and modern penguin bone and feather. We selected seven penguin bones and feathers and six sediments from the longest sediment core and performed AMS14C dating. The results indicate that penguins occupied the Vestfold Hills as early as 8500 calibrated years before present (cal. yrbp), following local deglaciation and the formation of the ice free area. This is the first report on the Holocene history of penguins in the Vestfold Hills. As in other areas of Antarctica, penguins occupied this area as soon as local ice retreated and the ice free area formed, and they are very sensitive to climatic and environmental changes. This work provides the foundation for understanding the history of penguins occupation in Vestfold Hills, East Antarctica.

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Mineralogical implications for the Late Pleistocene glaciation in Amery Oasis, East Antarctica, from a lake sediment core

Antarctic Science ◽

10.1017/s0954102007000880 ◽

2008 ◽

Vol 20 (2) ◽

pp. 169-172 ◽

Cited By ~ 4

Author(s):

Nadja Hultzsch ◽

Bernd Wagner ◽

Bernhard Diekmann ◽

Duanne White

Keyword(s):

Sediment Core ◽

Surface Sediments ◽

Mineralogical Composition ◽

East Antarctica ◽

Pleistocene Glaciation ◽

Lower Section ◽

Rock Outcrops ◽

Ice Caps ◽

The Core ◽

Lake Sediment Core

AbstractThe clay mineralogical composition of a 552 cm long sediment core from Lake Terrasovoje in Amery Oasis, East Antarctica, was analysed and compared with that in surface sediments from other locations in the vicinity. The lower part of the sediment core is formed by sub- and proglacial sediments with a dominance of smectite and illite, and lower amounts of kaolinite and chlorite. The upper part of the core is deposited after 12 500 cal yr bp and mainly composed of illite and kaolinite, with low amounts of smectite and chlorite, such as found in samples from rock outcrops and covering sediments throughout Amery Oasis. The clay composition in the lower section of core Lz1005 suggest that the basin of Lake Terrasovoje was filled by a 150–200 m thickened Nemesis Glacier prior to 12 500 cal yr bp rather than by local ice caps.

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

Quaternary Research ◽

10.1016/j.yqres.2010.04.004 ◽

2010 ◽

Vol 74 (1) ◽

pp. 23-25 ◽

Cited By ~ 4

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.

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Paleoenvironments of a proglacial lake in Schirmacher Oasis, East Antarctica: Insights from quartz grain microtextures

Polish Polar Research ◽

10.1515/popore-2017-0002 ◽

2017 ◽

Vol 38 (1) ◽

pp. 1-19 ◽

Cited By ~ 5

Author(s):

Abhijit Mazumder ◽

Pawan Govil ◽

Ratan Kar ◽

Narath Meethal Gayathri ◽

Keyword(s):

Cluster Analysis ◽

Sediment Core ◽

Grain Morphology ◽

East Antarctica ◽

Interglacial Period ◽

Sediment Samples ◽

The Core ◽

Paleoenvironmental Changes ◽

Schirmacher Oasis ◽

Proglacial Lake

AbstractEighteen sediment samples from a 36 cm long sediment core retrieved from a proglacial lake (namely P 11) situated in the Schirmacher Oasis, East Antarctica, were analysed for the study of quartz grain morphology and microtexture, along with sand percentage, to reconstruct the paleoenvironmental changes in the lake during the Holocene. The age of the core ranges from 3.3 ka BP to 13.9 ka BP. The quartz grain morphology and microtexture reveal significant evidences of glacial transport along with some eolian and aqueous activities. On the basis of predominance of these signatures and the zonation from CONISS Cluster Analysis on the percentages of characteristic grain morphology and microtextures, the entire core has been subdivided into three major zones. From the paleoenvironmental perspective, it can be concluded that there is an onset of interglacial period at the advent of Holocene (12.3 ka BP), which reigned until 5.3 ka BP and thereafter, again a glacial environment prevailed until 3.3 ka BP with some variations in-between. The results indicate probable alternative colder and less colder phases in the study area, which are also well supported by the respective sand percentages in the sediments.

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Methanesulphonic acid movement in solid ice cores

Annals of Glaciology ◽

10.3189/172756404781814645 ◽

2004 ◽

Vol 39 ◽

pp. 540-544 ◽

Cited By ~ 13

Author(s):

Barbara T. Smith ◽

Tas D. Van Ommen ◽

Mark A. J. Curran

Keyword(s):

Diffusion Coefficient ◽

Biological Activity ◽

Sea Ice ◽

Diffusion Mechanism ◽

Ice Core ◽

Ice Cores ◽

East Antarctica ◽

The Core ◽

Central Value

AbstractMethanesulphonic acid (MSA) is an important trace-ion constituent in ice cores, with connections to biological activity and sea-ice distribution. Post-depositional movement of MSA has been documented in firn, and this study investigates movement in solid ice by measuring variations in MSA distribution across several horizontal sections from an ice core after 14.5 years storage. The core used is from below the bubble close-off depth at Dome Summit South, Law Dome, East Antarctica. MSA concentration was studied at 3 and 0.5 cm resolution across the core widths. Its distribution was uniform through the core centres, but the outer 3 cm showed gradients in concentrations down to less than half of the central value at the core edge. This effect is consistent with diffusion to the surrounding air during its 14.5 year storage. The diffusion coefficient is calculated to be 2 ×10–13 m2 s–1, and the implications for the diffusion mechanism are discussed.

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PRELIMINARY STUDIES ON SEDIMENT CORE FROM THE TYRO BASIN

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11733 ◽

2017 ◽

Vol 50 (1) ◽

pp. 324

Author(s):

M. Geraga ◽

Ch. Anagnostou ◽

I. Iliopoulos ◽

M. Kontali

Keyword(s):

Mediterranean Sea ◽

Sediment Core ◽

Eastern Mediterranean ◽

Planktonic Foraminifera ◽

Mineralogical Composition ◽

Eastern Mediterranean Sea ◽

Sediment Samples ◽

Preliminary Results ◽

The Core ◽

Mineral Constituents

The present paper summarizes the preliminary results of the mineralogical and micropaleontological analysis conducted on sediment samples from core TYR05 retrieved from the anoxic and hypersaline Tyro basin in the eastern Mediterranean Sea. The core comprises a complex lithostratigraphic sequence attributed to the strong geodynamic regime of the area. The planktonic foraminifera associations present fluctuations which coincide with changes in the lithology of the core. The mineralogical composition of the sediments shows influence from the evaporites developed on the bottom of the basin. The mineral constituents in association to the microfauna assemblages suggest that the sediments include sapropelic layers. Further analyses are needed in order to determine safely the sapropelic deposits.

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Landform evolution in the Marine Plain region, Vestfold Hills, East Antarctica

Antarctic Science ◽

10.1017/s0954102006000289 ◽

2006 ◽

Vol 18 (2) ◽

pp. 239-259 ◽

Cited By ~ 4

Author(s):

Patrick G. Quilty

Keyword(s):

Sedimentary Rocks ◽

East Antarctica ◽

Patterned Ground ◽

Antarctic Ice Sheet ◽

Landform Evolution ◽

Ice Load ◽

Exposed Rock ◽

Plain Region ◽

Vestfold Hills ◽

Land Surfaces

Landforms of Marine Plain in the Vestfold Hills contrast with those of most in the Vestfold Hills. They include consistent land surfaces at 40+ m and 25 m, characteristics controlled by orientation of rock features, and imprints of phases of glaciation, deglaciation and marine and freshwater inundation. The 40+ m surface is widespread in the Vestfold Hills and has been noted previously. The 25 m level was an earlier coastline, is more localized and marked by water rounded boulders; it serves to differentiate clearly between two terrains of different relief and erratic distribution. The Pliocene sedimentary rocks below the 25 m level have been dislocated, probably during an interval of glaciotectonism caused by northward movement of sediments under an ice load due to northern extension of the Sørsdal Glacier or expansion of the East Antarctic Ice Sheet some time after the mid-Pliocene. Soil development is active. These features are accompanied by the normal aspects of a glaciated landscape such as glacial striations, sand wedges, erratics, and patterned ground. Wind has been important in transporting sand and developing honeycomb weathering on exposed rock faces.

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Membrane Deformation of Endothelial Surface Layer Interspersed with Syndecan-4: A Molecular Dynamics Study

Annals of Biomedical Engineering ◽

10.1007/s10439-019-02353-7 ◽

2019 ◽

Vol 48 (1) ◽

pp. 357-366 ◽

Cited By ~ 1

Author(s):

Xi Zhuo Jiang ◽

Liwei Guo ◽

Kai H. Luo ◽

Yiannis Ventikos

Keyword(s):

Molecular Dynamics ◽

Lipid Membrane ◽

Environmental Changes ◽

Core Protein ◽

Membrane Surface ◽

Circulatory System ◽

Endothelial Glycocalyx ◽

Force Transmission ◽

Membrane Deformation ◽

The Core

Abstract The lipid membrane of endothelial cells plays a pivotal role in maintaining normal circulatory system functions. To investigate the response of the endothelial cell membrane to changes in vascular conditions, an atomistic model of the lipid membrane interspersed with Syndecan-4 core protein was established based on experimental observations and a series of molecular dynamics simulations were undertaken. The results show that flow results in continuous deformation of the lipid membrane, and the degree of membrane deformation is not in monotonic relationship with the environmental changes (either the changes in blood velocity or the alteration of the core protein configuration). An explanation for such non-monotonic relationship is provided, which agrees with previous experimental results. The elevation of the lipid membrane surface around the core protein of the endothelial glycocalyx was also observed, which can be mainly attributed to the Coulombic interactions between the biomolecules therein. The present study demonstrates that the blood flow can deform the lipid membrane directly via the interactions between water molecules and lipid membrane atoms thereby affecting mechanosensing; it also presents an additional force transmission pathway from the flow to the lipid membrane via the glycocalyx core protein, which complements previous mechanotransduction hypothesis.

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Late Quaternary Vegetational Changes in a Marsh Forest in Southeastern Brazil with Comments on Prehistoric Human Occupation

Radiocarbon ◽

10.2458/azu_rc.57.18198 ◽

2015 ◽

Vol 57 (5) ◽

pp. 737-753 ◽

Cited By ~ 2

Author(s):

Walter Mareschi Bissa ◽

Mauro B de Toledo

Keyword(s):

Sediment Core ◽

Environmental Changes ◽

Human Impacts ◽

Late Quaternary ◽

Southeastern Brazil ◽

Pollen Record ◽

Important Indicator ◽

Climate Conditions ◽

Ams Radiocarbon Dating ◽

Se Brazil

This article presents a palynological study carried out on a sediment core from a peat deposit in Serra de Botucatu, in SÃo Paulo State, southeastern Brazilian Plateau. This region has been covered by grassland vegetation and forest patches throughout the recorded period. AMS radiocarbon dating plus palynological analysis of 27 samples from the sediment core allowed the recognition of several environmental changes that took place during the last 33,000 yr recorded in the core. The relationship between sedimentation rates and changes in the abundance of plants recognized through their pollen record, particularly a few important indicator species, provided the paleoenvironmental history for the Serra de Botucatu region, allowing the identification of changes in climate conditions and comparison with other regions in Brazil. One of the most remarkable features of this record is the cold and humid conditions during the Last Glacial Maximum, which diverges from previous interpretations for southeastern and southern Brazil but is in good agreement with paleoclimatic data from trace elements from cave stalagmites in SE Brazil. No indications of human impacts on the vegetation were found in this record.

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Lake Lerna: investigating Hercules' ancient myth

10.5194/egusphere-egu2020-1045 ◽

2020 ◽

Author(s):

Danae Thivaiou ◽

Efterpi Koskeridou ◽

Christos Psarras ◽

Konstantina Michalopoulou ◽

Niki Evelpidou ◽

...

Keyword(s):

Environmental Changes ◽

Coarse Sand ◽

Natural Environments ◽

Aegean Area ◽

Freshwater Gastropods ◽

The Core ◽

Interdisciplinary Field ◽

The People ◽

History Of ◽

Age Model

Greece and the Aegean area are among the first areas in Europe to have been occupied by humans. The record of human interventions in natural environments is thus particularly rich. Some of the interventions of the people inhabiting various localities of the country have been recorded in local mythology. Through the interdisciplinary field of geomythology it is possible to attempt to uncover the relationships between the geological history of early civilizations and ancient myths.In the present work, we focused on the history of Lake Lerni in the Eastern Peloponnese, an area that is better known through the myth of Hercules and the Lernaean Hydra. The area of the lake &#8211; now dried and cultivated &#8211; was part of a karstic system and constituted a marshland that was a source of diseases and needed to be dried.A new core is studied from the area of modern-day Lerni using palaeontological methods in order to reconstruct environmental changes that occurred during the last 6.000 years approximately. The area is known to have gone from marsh-lacustrine environments to dryer environments after human intervention or the intervention of Hercules according to mythology. Levels of peat considered to represent humid intervals were dated using the radiocarbon method so as to have an age model of the core. Samples of sediment were taken every 10 cm; the grain size was analysed for each sample as well as the fossil content for the environmental reconstruction.The presence of numerous freshwater gastropods reflects the intervals of lacustrine environment accompanied with extremely fine dark sediment. Sedimentology is stable throughout the core with few levels of coarse sand/fine gravel, only changes in colour hint to multiple levels richer in organic material.

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