Preliminary results of ionic concentrations in snow pits along the Zhongshan–Dome A traverse route, Antarctica

AbstractDuring an inland traverse expedition along the route from Zhongshan station on the coast to Dome A (about 4200ma.s.l.; 1400 km from Zhongshan) in East Antarctica in 1998/99, three snow pits with a depth of 2.1–3.3m were sampled continuously. Snow pits were located at sites 800–1100km from the coast, with altitudes varying from 2850 to 3760 m. The samples were analyzed for stable oxygen isotope and major ions. Seasonal variations in δ18O are not clear, so initial dating was made through comparison of concentration profiles of major ions and then adjusted according to the visible stratigraphy. Generally, average ionic concentrations decrease with increasing altitude and hence distance from the coast, but NH4+ and Ca2+ have relatively high values at a site 1000 km inland. Ionic concentrations tend to increase with depth at lower altitudes, but the opposite is true at higher altitudes. Accumulation rates increase with depth at site DT401 (3760ma.s.l.; 1097 km from Zhongshan) and decrease at DT364 (3380ma.s.l.; 1022 km from Zhongshan) and DT263 (2850ma.s.l.; 820 km from Zhongshan), suggesting that differences in regional trends exist. In all snow pits, Na+ and Cl– concentration profiles have a very good positive correlation. Profiles of nssSO42– in the pits show quite different features. At 3760ma.s.l, no remarkable nssSO42– peaks can be distinguished, but one and three peak sets are quite striking at 3380 and 2850 m, respectively.

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Identification of multiple natural and anthropogenic sources of dust in snow from Zhongshan Station to Dome A, East Antarctica

Journal of Glaciology ◽

10.1017/jog.2018.72 ◽

2018 ◽

Vol 64 (248) ◽

pp. 855-865 ◽

Cited By ~ 8

Author(s):

ZHIHENG DU ◽

CUNDE XIAO ◽

MINGHU DING ◽

CHUANJIN LI

Keyword(s):

Major Ions ◽

Isotope Composition ◽

Isotopic Signature ◽

East Antarctica ◽

Anthropogenic Sources ◽

Dome A ◽

Long Distance ◽

Anthropogenic Pollutants ◽

Zhongshan Station ◽

Snow Samples

ABSTRACTThe stable oxygen isotope composition, major ions and isotopic compositions of strontium (Sr), neodymium (Nd) and lead (Pb) in insoluble dust from recent surface snow samples along the transect from the Zhongshan and Progress stations (located on the Amery Ice Shelf, East Antarctica) to Dome A (Summit, Antarctica) were analysed. No previous isotopic fingerprinting studies have been conducted for this transect. These data were used to document the dust provenances in Antarctica along the transect up to the highest site, Dome A, for the first time. The insoluble dust in snow samples along the coast displays an overall crust-line isotopic signature that is characterised by highly radiogenic 87Sr/86Sr values and less radiogenic 143Nd/144Nd values. These signatures are comparable with those of samples collected near the ice-free areas of the Zhongshan and Progress stations. Spatial differences are statistically significant along the transect, and the Sr, Nd and Pb isotope components in insoluble dust from two continuous snow samples at Dome A exhibit marked differences, indicating that additional dust reaches the East Antarctic Plateau. The isotopic characteristics of insoluble dust from this transect indicate that the long-distance natural dust and anthropogenic pollutants in these samples primarily originate from Australia.

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Surface mass balance and stable oxygen isotope ratios from shallow firn cores on Fimbulisen, East Antarctica

Annals of Glaciology ◽

10.3189/2012aog60a102 ◽

2012 ◽

Vol 53 (60) ◽

pp. 70-78 ◽

Cited By ~ 8

Author(s):

E. Schlosser ◽

H. Anschütz ◽

E. Isaksson ◽

T. Martma ◽

D. Divine ◽

...

Keyword(s):

Stable Isotope ◽

Mass Balance ◽

Isotope Ratios ◽

Stable Isotope Ratios ◽

Surface Mass Balance ◽

Accumulation Rates ◽

Stable Oxygen Isotope ◽

Surface Mass ◽

Oxygen Isotope Ratios ◽

Stable Oxygen

AbstractThe mass balance of Antarctica is one of the crucial factors for determining sea-level change in a warming climate. The marginal zones of the continent, namely the ice shelves, are most sensitive to climate change. During the 2009/10 austral summer an extensive glaciological field campaign was carried out on Fimbulisen, an ice shelf in East Antarctica, to investigate its recent surface mass balance. Shallow (10–18 m) firn cores were drilled and accumulation rates and stable-isotope ratios determined. For firn-core dating, two different methods were compared: (1) seasonal variations of stable oxygen isotope ratios (δ18O), and (2) dielectric profiling, including using the volcanic eruptions of Pinatubo, Philippines (1991), and El Chichόn, Mexico (1982), as time markers. The mean annual accumulation for the period 1992–2009 ranges from 298 to 349 mmw.e. a–1. The interannual variability at the drilling sites is >30%. Accumulation rates show a weak decreasing trend during the past 20–30 years, which is statistically significant only for one of the cores. Stable-isotope ratios were compared to the snowfall temperature of Neumayer station. Neither the temperatures nor the δ18O values show any trend for the investigated time period.

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