SEGH Articles

Dust Deposition in snow from NorthEast Antarctica: mineralogical, morphological and chemical characterization

05 October 2014
Aubry Vanderstraeten is a PhD student and won the runner-up prize for best student poster at SEGH 2014.


Mineral dusts are a major source of micronutrients (e.g. Fe) that limit phytoplankton growth in the open ocean, in particular in the so-called “High Nutrient Low Chlorophyll” (HNLC) oceanic zones. The southern Ocean is by far the largest of all HNLC regions and thus has the potential to greatly enhance the biological CO2 pump at the global scale. As the aerosol fluxes and sources in the southern Ocean are not well constrained and the potential impact of anthropogenic airborne particles may be larger than expected, a multidisciplinary study is being carried out on dust-bearing snow samples collected in NE Antarctica. Our goals are multiple: (i) determine the mineralogy, morphology and chemical composition of these dusts and, (ii) quantify, by using heavy stable isotopic signatures, the origin and the relative contribution of desert-derived, volcanic and anthropogenic particles in the dust, (iii) estimate the bioavailable fraction of bio-essential elements such as Fe through chemical extraction.

Snow samples were collected at four sites: two a few kilometres from the sea, at the summit of the Derwael Ice Rise (about 200km North of the Belgian Princess Elisabeth Station) and two other locations in a continental area (~225km inland) around the Princess Elisabeth station in the Sør Rondane Mountains. Three litres of snow from each site were melted and filtrated on 0.2 µm poresize NucleporeÓ polycarbonate filters in an ISO 5-class clean room. Subsequently, a series of single particle analyses were performed by (i) FEG-SEM (Field Emission Gun-Scanning Electron Microscopy) to determine particles-size distribution of dust; (ii) automated-SEM-EDS (Energy Dispersive Spectroscopy) to estimate the chemical composition of individual dust particles; (iii) TEM-SAED analysis (Transmission Electron Microscopy Selected Area Electron Diffraction) to identify the minerals present. In addition, trace element compositions of the bulk samples were analyzed by high-resolution ICP-MS.

Preliminary data in elemental composition and mineralogy indicate similarities between dust samples and the rock-forming minerals from the Sør Rondane Mountains suggesting a local dust source. However, major distinctions can be made between coastal and inland dust samples: (i) mineralogical distributions are very distinct; (ii) a large proportion of the quartz and feldspath dust particles exhibit surprisingly enrichment in iron (less than 20% of particles for inland samples and up to 80% for coastal samples), which is probably due to surface Fe-rich coating/aggregates; (iii) coastal samples are heavily enriched (vs. upper continental crust reference values) in Pb and Ni. These Fe, Pb and Ni enrichment trends tend to suggest an external and distal source of dust at the coast, potentially impacted by anthropogenic activities.

To complement those preliminary results, new sampling campaign will take place in December 2014 at the same locations to acquire large quantity of snow. In addition, passive dust collectors will be placed for a period of one year along a transect connecting the Sør Rondane Mountains and the Derwael Ice Rise. The perspectives of this new sampling campaign aim to fulfil our analysis plan through isotopic analyses and chemical extractions.

This in-depth characterisation study will improve our knowledge and understanding of dusts reaching the coast of NE-Antarctica, which represent a proxy of the dust materials supplied to the Southern Ocean. 

by Aubry Vanderstraeten, PhD student

Keep up to date

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • The society for environmental Geochemistry and health (SEGH): a retrospect 2019-02-22
  • Air quality and PM 10 -associated poly-aromatic hydrocarbons around the railway traffic area: statistical and air mass trajectory approaches 2019-02-19


    Diesel engine railway traffic causes atmosphere pollution due to the exhaust emission which may be harmful to the passengers as well as workers. In this study, the air quality and PM10 concentrations were evaluated around a railway station in Northeast India where trains are operated with diesel engines. The gaseous pollutant (e.g. SO2, NO2, and NH3) was collected and measured by using ultraviolet–visible spectroscopy. The advanced level characterizations of the PM10 samples were carried out by using ion chromatography, Fourier-transform infrared, X-ray diffraction, inductively coupled plasma optical emission spectrometry , X-ray photoelectron spectroscopy, field-emission scanning electron microscopy with energy-dispersive spectroscopy, and high-resolution transmission electron microscopy with energy-dispersive spectroscopy techniques to know their possible environmental contaminants. High-performance liquid chromatography technique was used to determine the concentration of polycyclic aromatic hydrocarbons to estimate the possible atmospheric pollution level caused by the rail traffic in the enclosure. The average PM10 concentration was found to be 262.11 µg m−3 (maximum 24 hour) which indicates poor air quality (AQI category) around the rail traffic. The statistical and air mass trajectory analysis was also done to know their mutual correlation and source apportionment. This study will modify traditional studies where only models are used to simulate the origins.

  • The geochemistry of geophagic material consumed in Onangama Village, Northern Namibia: a potential health hazard for pregnant women in the area 2019-02-18


    Ingestion of geophagic materials might affect human health and induce diseases by different ways. The purpose of this study is to determine the geochemical composition of geophagic material consumed especially by pregnant women in Onangama Village, Northern Namibia and to assess its possible health effects. X-ray fluorescence and inductively coupled plasma mass spectrometry were used in order to determine the major, and trace elements as well as anions concentrations of the consumed material. The geochemical analysis revealed high concentrations of aluminium (Al), calcium (Ca), iron (Fe), magnesium (Mg), manganese (Mn), potassium (K), sodium (Na), and silica (Si); and trace elements including arsenic (As), chromium (Cr), mercury (Hg), nickel (Ni) and vanadium (V) as well as sulphate (SO42−), nitrate (NO3), and nitrite (NO2) anions comparing to the recommended daily allowance for pregnant women. The pH for some of the studied samples is alkaline, which might increase the gastrointestinal tract pH (pH < 2) and cause a decrease in the bioavailability of elements. The calculated health risk index (HRI > 1) revealed that Al and Mn might be a potential risk for human consumption. Based on the results obtained from the geochemical analysis, the consumption of the studied material might present a potential health risk to pregnant women including concomitant detrimental maternal and foetal effects.