D.C. Conductivity of Antarctic Ice in Relation to Its Chemistry

Legrand, Michel; Petit, Jean-Claude; Korotkevich, Y. S.

doi:10.1051/jphyscol:1987183

Cited by 22 publications

(22 citation statements)

References 1 publication

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“…The chemistry could give rise to a nonlinear response if acid associated with different counter anions gave different ECM responses. In particular, since sulphate is probably the dominant counter ion at high acidities, but it is less dominant at low acidities, an apparent nonlinearity would arise if acid associated with sulphate gave a lower ECM response than that associated with nitrate and chloride, as discussed above [Legrand et al, 1987]. However, as also discussed, the present data do not allow us to resolve this question.…”

Section: Chemistrymentioning

confidence: 53%

The chemical basis for the electrical stratigraphy of ice

Moore¹,

Wolff²,

Clausen³

et al. 1992

J. Geophys. Res.

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Antarctic and Greenland ice core samples were studied using two different stratigraphic electrical techniques. The electrical conductivity measurement (ECM) technique is adc method, while dielectric profiling (DEP) is an ac method. It was found that ECM responds only to acid, even in large excess of neutral salt concentrations. DEP responds to both acid and salt content of the ice. Acids may be giving rise to conduction through an increase in the number of ionisation defects, or through a network of liquid veins between ice grains. Salts on the other hand appear to give rise to Bierrum defects, which are bound charges and cannot provide adc current, but do produce a dielectric ac conductivity. The two methods can be used together to give a rapid prediction of both acid and salt content of cores. This may be of particular use in Wisconsin-age ice from Greenland, but can generally be used to define parts of cores worthy of detailed chemical study. 2. SAMPLES Antarctic samples were from the core drilled at Dolleman Island (70ø35'S, 60ø55•, elevation 400 m, mean annual temperature -17øC, average accumulation over 200 years • 0.38 m ice/year) in the Antarctic Peninsula. Chemical and DEP measurements made previously on sections of this core have been described elsewhere [Mulvaney and Peel, 1988; Moore et al., 1989]. Dolleman Island is a coastal site that exhibits high concentrations of maxine ions, with mean Na + values above 10 gM, and peak Na + concentrations above 100 !xlVI. The chemistry contrasts with that of cores from central Antarctica, where, as at South Pole, Na + may average at less than 1 gM [Legrand and Delmas, 1984]. The core also shows strong peaks in sulphate, in excess of that attributable to sea salt, and these are associated with high H + contents. The acidic sulphate is believed to be produced mainly by photochemical oxidation of biogenically derived sulphur gases, and it peaks in summer (based on dating by cycles of oxygen isotope ratios in the ice). The marine ions tend to peak in the autumn/winter period. The existence of a wide range of impurity concentrations, and of strong peaks in both acid and marine ions, separated in depth, makes this a particularly useful core for the study of the effect of chemistry on the electrical properties of the ice. Moom• •,,•L.: Ic• C3mM•STaY • ELE•I½• STRATIGRAPHY 1889 Antarctic ice, Ann. Glaciol., 11,194-197, 1988. Zanolini, F., Conductimetrie et chimie de la glace ii D57 (Terre Ad6lie): Application • la recherche du pa16ovolcanisme, Bull. Pirpsev 76, Cent. Natl. de la Rech. Sci./Inst. Natl. d'Astron. et de Geophys., Verfi•res-le-

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Section: Chemistrymentioning

confidence: 53%

The chemical basis for the electrical stratigraphy of ice

Moore¹,

Wolff²,

Clausen³

et al. 1992

J. Geophys. Res.

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“…This form of analysis (ECM) has been shown to be a very useful tool in the stratigraphic analysis of ice cores. The current flowing between the electrodes depends non-linearly on the acid concentration of the ice core [Hammer, 1983, Legrand et al, 1987…”

Section: Acid Conduction Mechanismmentioning

confidence: 69%

Sea salt dependent electrical conduction in polar ice

Moore¹,

Paren²,

Oerter³

1992

J. Geophys. Res.

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A 45 m length of ice core from Dolleman Island, Antarctic Peninsula has been dielectrically analysed at 5 cm resolution using the dielectric profiling (DEP) technique. The core has also been chemically analysed for major ionic impurities. A statistical analysis of the measurements shows that the LF (low frequency) conductivity is determined both by neutral salt and acid concentrations. The statistical relationships have been compared with results from laboratory experiments on ice doped with HF (hydrogen fluoride). Salts (probably dispersed throughout the ice fabric) determine the dielectric conductivity. The salt conduction mechanism is probably due to Bjerrum L defects alone, created by the incorporation of chloride ions in the lattice. Samples of ice from beneath the Filchner‐Ronne Ice Shelf were also measured and display a similar conduction mechanism below a solubility limit of about 400 μM of chloride. The temperature dependence of the neutral salt, acid and pure ice contributions to the LF conductivity of natural ice between −70°C and 0°C is discussed. These results allow a comprehensive comparison of dielectric and chemical data from natural ice.

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“…And based on this conclusion, the volcanic eruptions were resumed in historic periods. In Antarctic ice core the ECM and H + , SO 4 2− , NO 3 − , Cl − also have very good correlation (Legrand et al, 1987), while silicate, which mainly comes from the earth's crust, is negatively correlated with ECM, indicating that the mass of Antarctic ice is mainly originated from the ocean source. This is different from the results of the Tianshan Mountains of this work.…”

Section: Comparison With the Researches Of The Polar Regions And Qingmentioning

confidence: 82%

The pH value and electrical conductivity of atmospheric environment from ice cores in the Tianshan Mountains

Dong

Zhang

et al. 2009

J. Geogr. Sci.

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Electrical Conductivity Measurement (ECM) from ice core is a representative index for atmospheric environmental change. The pH value and ECM from three shallow ice cores (each 3.85 m, 231 ice samples total) on Glacier No.1 at the headwater of Urumqi River, Glacier No.48 in Kuitun area, and Miaoergou Glacier in Hami area in the eastern Tianshan Mountains, western China, were measured and analyzed for atmospheric environment records research. Ice core record shows that the changing trend of pH and ECM in three sites in recent years is different: ECM in Kuitun increases with the ice depth change, but ECM in Hami and Urumqi Glacier No.1 ice cores show a decreasing trend. Average ECM value in Hami is much larger than other two sites, just as the dust concentration and ions concentration are also very high in this site. ECM records in all three sites are mainly affected by aerosol mineral dust of Central Asia, and correlative coefficients of ECM and mineral ions such as Ca 2+ , Mg 2+ , Na + are all significantly high. The pH value and ECM are also significantly high correlative coefficients in the eastern Tianshan Mountains. Comparison between the eastern Tianshan Mountains and other sites in western China, and Polar Regions, shows that the difference of ECM can very well reflect the spatial difference of worldwide atmospheric environment.

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D.C. Conductivity of Antarctic Ice in Relation to Its Chemistry

Cited by 22 publications

References 1 publication

The chemical basis for the electrical stratigraphy of ice

The chemical basis for the electrical stratigraphy of ice

Sea salt dependent electrical conduction in polar ice

The pH value and electrical conductivity of atmospheric environment from ice cores in the Tianshan Mountains

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