Physical and chemical studies in the region of the southern slope of Mount Elbrus, Caucasus

AbstractFor glaciological and meteorological reasons Mount Elbrus, Caucasus, was chosen as a site for physical and chemical pilot studies of ice cores. This study was the first step towards systematic studies of impurities in glacier ice on Mount Elbrus. In 1900 two ice cores, each 17 m deep and spaced 10 m apart, were taken at an elevation of 4100 m on the Bolshoy Azau glacier on the western slopes of Mount Elbrus. The cores were used for different physical and chemical analyses. Structure, texture and ice microstructure were studied. Chemical analyses of major ions (SO42−, NO3−, K+ and Na+) and measurements of insoluble light-absorbing material and radioactivity (137Cs and total β activity) were made. With the results of the physical and chemical analyses of these two ice cores, the possibilities of utilising the ice for the study of trace substances deposited after long-range transport from Europe were explored. Ice-stratigraphic methods made it possible to establish the annual accumulation rate. A reference horizon was established from the depth variation of 137Cs and total β activities that showed a well-defined peak of their activities coinciding in time with the 1986 Chernobyl accident. The results of this study show that Mount Elbrus is a useful archive for atmospheric composition downwind of Europe.

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Physical and chemical studies in the region of the southern slope of Mount Elbrus, Caucasus

Journal of Glaciology ◽

10.1017/s0022143000002550 ◽

1998 ◽

Vol 44 (147) ◽

pp. 214-222 ◽

Cited By ~ 5

Author(s):

A. M. Bazhev ◽

O. Rototaeva ◽

J. Heintzenberg ◽

M. Stenberg ◽

J. F. Pinglot

Keyword(s):

Major Ions ◽

Accumulation Rate ◽

Ice Cores ◽

Atmospheric Composition ◽

Chemical Analyses ◽

Pilot Studies ◽

Glacier Ice ◽

Chemical Studies ◽

A Site ◽

Physical And Chemical

Abstract For glaciological and meteorological reasons Mount Elbrus, Caucasus, was chosen as a site for physical and chemical pilot studies of ice cores. This study was the first step towards systematic studies of impurities in glacier ice on Mount Elbrus. In 1900 two ice cores, each 17 m deep and spaced 10 m apart, were taken at an elevation of 4100 m on the Bolshoy Azau glacier on the western slopes of Mount Elbrus. The cores were used for different physical and chemical analyses. Structure, texture and ice microstructure were studied. Chemical analyses of major ions (SO4 2−, NO3−, K+ and Na+) and measurements of insoluble light-absorbing material and radioactivity (137Cs and total β activity) were made. With the results of the physical and chemical analyses of these two ice cores, the possibilities of utilising the ice for the study of trace substances deposited after long-range transport from Europe were explored. Ice-stratigraphic methods made it possible to establish the annual accumulation rate. A reference horizon was established from the depth variation of 137Cs and total β activities that showed a well-defined peak of their activities coinciding in time with the 1986 Chernobyl accident. The results of this study show that Mount Elbrus is a useful archive for atmospheric composition downwind of Europe.

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Ice Core Studies of Ward Hunt Ice Shelf, 1960

Journal of Glaciology ◽

10.3189/s0022143000028562 ◽

1964 ◽

Vol 5 (37) ◽

pp. 39-59 ◽

Cited By ~ 1

Author(s):

R. H. Ragle ◽

R. G. Blair ◽

L. E. Persson

Keyword(s):

Ice Core ◽

Polarized Light ◽

Ice Cores ◽

Laboratory Analysis ◽

Dartmouth College ◽

The Arctic ◽

Ice Shelf ◽

Glacier Ice ◽

Initial Work ◽

Physical And Chemical

AbstractA four-man party representing the Arctic Institute of North America and the Department of Geology, Dartmouth College, went to the Ward Hunt Ice Shelf in 1960 to obtain ice cores for subsequent laboratory analysis. The overall objective of the project was to study the structural and stratigraphic history of the shelf and its relationship to the environment through laboratory analysis of the cores, using stratigraphic. petrologic, chemical, and physical methods.The four cores obtained were logged, packed, and shipped to Dartmouth College for detailed study. The stratigraphy and structure of the ice were studied under natural and plane polarized light conditions. The results of this initial work showed that the cores were composed of four ice types: glacier ice, lake ice, sea ice, and transition ice. Chlorinity, sulfate, and density profiles complemented megascopic studies and were most useful criteria for plotting stratigraphie changes in ice type.Results of the investigations thus far have yielded new information about the gross structure and stratigraphy of the ice shelf and re-entrant. They have also shown that the physical and chemical techniques employed will be useful in future ice-core analysis.

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Ice Core Studies of Ward Hunt Ice Shelf, 1960

Journal of Glaciology ◽

10.1017/s0022143000028562 ◽

1964 ◽

Vol 5 (37) ◽

pp. 39-59 ◽

Cited By ~ 42

Author(s):

R. H. Ragle ◽

R. G. Blair ◽

L. E. Persson

Keyword(s):

Ice Core ◽

Polarized Light ◽

Ice Cores ◽

Laboratory Analysis ◽

Dartmouth College ◽

The Arctic ◽

Ice Shelf ◽

Glacier Ice ◽

Initial Work ◽

Physical And Chemical

Abstract A four-man party representing the Arctic Institute of North America and the Department of Geology, Dartmouth College, went to the Ward Hunt Ice Shelf in 1960 to obtain ice cores for subsequent laboratory analysis. The overall objective of the project was to study the structural and stratigraphic history of the shelf and its relationship to the environment through laboratory analysis of the cores, using stratigraphic. petrologic, chemical, and physical methods. The four cores obtained were logged, packed, and shipped to Dartmouth College for detailed study. The stratigraphy and structure of the ice were studied under natural and plane polarized light conditions. The results of this initial work showed that the cores were composed of four ice types: glacier ice, lake ice, sea ice, and transition ice. Chlorinity, sulfate, and density profiles complemented megascopic studies and were most useful criteria for plotting stratigraphie changes in ice type. Results of the investigations thus far have yielded new information about the gross structure and stratigraphy of the ice shelf and re-entrant. They have also shown that the physical and chemical techniques employed will be useful in future ice-core analysis.

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Characteristics of bubble volumes in firn-ice transition layers of ice cores from polar ice sheets

Annals of Glaciology ◽

10.1017/s0260305500016293 ◽

1994 ◽

Vol 20 ◽

pp. 95-100

Author(s):

Takao Kameda ◽

Renji Naruse

Keyword(s):

Bulk Density ◽

Classical Method ◽

Accumulation Rate ◽

Bubble Formation ◽

Ice Sheets ◽

Ice Cores ◽

Ideal Gas ◽

Polar Ice ◽

Polar Ice Sheets ◽

Glacier Ice

The air-bubble formation process has been studied experimentally by using five ice cores from the Greenland and Antarctic ice sheets. Bubble volumes in firn-ice samples were measured by a classical method based on Boyle Mariotte's law for an ideal gas. It was found that the bubble volume varies with depth as a function of bulk density in the firn-ice transition layer, which is represented by an exponential function of firn density. Air bubbles start to form rapidly at a bulk density of 0.763–0.797 Mg m-3. This density (ρib) seems to be correlated with the ice temperature in the ice sheets; ρibincreases with a decrease in the ice temperature. Vbshows the maximum value in the density range 0.819–0.832 Mg m-3. The corresponding porosity of the density ranges between 0.110 and 0.097. This porosity does not seem to correlate with ice temperature or accumulation rate at the coring site. These characteristics of firn densities probably affect the amount of entrapped air in glacier ice (total air content) in polar ice sheets.

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Seasonal Fluctuations of Physical and Chemical Parameters of a Weir Basin in a Regulated West Norwegian River

Hydrology Research ◽

10.2166/nh.1981.0003 ◽

1981 ◽

Vol 12 (1) ◽

pp. 31-42 ◽

Cited By ~ 7

Author(s):

T. Baekken ◽

A. Fjellheim ◽

R. Larsen

Keyword(s):

Negative Correlation ◽

Major Ions ◽

Water Discharge ◽

Winter Season ◽

Significant Negative Correlation ◽

Specific Conductance ◽

Chemical Analyses ◽

Ionic Fluxes ◽

Physical And Chemical

Both before (1967-69) and after (1976-78) the regulation of the river Ekso in western Norway, physical and chemical analyses were made of the river water. After the regulation water samples for chemical analyses were taken at the inlet and outlet of a weir basin 375 m long which had recently been built to maintain the previous water level. The reduced water discharges and the increased water temperatures which followed the regulation presumably increased the amount and the quality of food available to detritusfeeding animals. The O2 content of the water was slightly reduced after the regulation. The pH was in the same range. Specific conductance (H20) and the concentrations of major ions before the regulation (Ca2+, Cl− NO3−-N, PO43−-P) and after the regulation (Ca2+, Mg2+, Cl−, SO42−, N03−-N. NH4+-N, PO43−-P) were also in the same range, but a distinct seasonal variation appeared after the regulation. These variations were thought to have three main reasons: 1) water discharge, 2) biological production, 3) nonspecified physicochemical relationships. Ionic fluxes through the weir basin were highest during the autumn. Only small differences were found between the inlet and outlet of the weir basin. Regression analyses based on the concentrations of major ions and water discharge after the regulation were made separatly for the summer and the winter season. H20 and SO42−-concentrations were not correlated to water discharge, Cl−-concentrations were positively correlated, whereas Ca2+ showed a negative correlation. Mg2+ and NO3−-N were not correlated to water discharge during the summer season, but showed a significant negative correlation during the winter.

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Characteristics of bubble volumes in firn-ice transition layers of ice cores from polar ice sheets

Annals of Glaciology ◽

10.3189/1994aog20-1-95-100 ◽

1994 ◽

Vol 20 ◽

pp. 95-100

Author(s):

Takao Kameda ◽

Renji Naruse

Keyword(s):

Bulk Density ◽

Classical Method ◽

Accumulation Rate ◽

Bubble Formation ◽

Ice Sheets ◽

Ice Cores ◽

Ideal Gas ◽

Polar Ice ◽

Polar Ice Sheets ◽

Glacier Ice

The air-bubble formation process has been studied experimentally by using five ice cores from the Greenland and Antarctic ice sheets. Bubble volumes in firn-ice samples were measured by a classical method based on Boyle Mariotte's law for an ideal gas. It was found that the bubble volume varies with depth as a function of bulk density in the firn-ice transition layer, which is represented by an exponential function of firn density. Air bubbles start to form rapidly at a bulk density of 0.763–0.797 Mg m-3. This density (ρib) seems to be correlated with the ice temperature in the ice sheets; ρib increases with a decrease in the ice temperature. Vb shows the maximum value in the density range 0.819–0.832 Mg m-3. The corresponding porosity of the density ranges between 0.110 and 0.097. This porosity does not seem to correlate with ice temperature or accumulation rate at the coring site. These characteristics of firn densities probably affect the amount of entrapped air in glacier ice (total air content) in polar ice sheets.

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Comparing past accumulation rate reconstructions in East Antarctic ice cores using <sup>10</sup>Be, water isotopes and CMIP5-PMIP3 models

Climate of the Past ◽

10.5194/cp-11-355-2015 ◽

2015 ◽

Vol 11 (3) ◽

pp. 355-367 ◽

Cited By ~ 9

Author(s):

A. Cauquoin ◽

A. Landais ◽

G. M. Raisbeck ◽

J. Jouzel ◽

L. Bazin ◽

...

Keyword(s):

High Resolution ◽

Isotopic Composition ◽

Accumulation Rate ◽

Ice Core ◽

Ice Cores ◽

Atmospheric Composition ◽

Water Isotopes ◽

Polar Regions ◽

Antarctic Plateau ◽

Good Agreement

Abstract. Ice cores are exceptional archives which allow us to reconstruct a wealth of climatic parameters as well as past atmospheric composition over the last 800 kyr in Antarctica. Inferring the variations in past accumulation rate in polar regions is essential both for documenting past climate and for ice core chronology. On the East Antarctic Plateau, the accumulation rate is so small that annual layers cannot be identified and accumulation rate is mainly deduced from the water isotopic composition assuming constant temporal relationships between temperature, water isotopic composition and accumulation rate. Such an assumption leads to large uncertainties on the reconstructed past accumulation rate. Here, we use high-resolution beryllium-10 (10Be) as an alternative tool for inferring past accumulation rate for the EPICA Dome C ice core, in East Antarctica. We present a high-resolution 10Be record covering a full climatic cycle over the period 269 to 355 ka from Marine Isotope Stage (MIS) 9 to 10, including a period warmer than pre-industrial (MIS 9.3 optimum). After correcting 10Be for the estimated effect of the palaeomagnetic field, we deduce that the 10Be reconstruction is in reasonably good agreement with EDC3 values for the full cycle except for the period warmer than present. For the latter, the accumulation is up to 13% larger (4.46 cm ie yr−1 instead of 3.95). This result is in agreement with the studies suggesting an underestimation of the deuterium-based accumulation for the optimum of the Holocene (Parrenin et al. 2007a). Using the relationship between accumulation rate and surface temperature from the saturation vapour relationship, the 10Be-based accumulation rate reconstruction suggests that the temperature increase between the MIS 9.3 optimum and present day may be 2.4 K warmer than estimated by the water isotopes reconstruction. We compare these reconstructions to the available model results from CMIP5-PMIP3 for a glacial and an interglacial state, i.e. for the Last Glacial Maximum and pre-industrial climates. While 3 out of 7 models show relatively good agreement with the reconstructions of the accumulation–temperature relationships based on 10Be and water isotopes, the other models either underestimate or overestimate it, resulting in a range of model results much larger than the range of the reconstructions. Indeed, the models can encounter some difficulties in simulating precipitation changes linked with temperature or water isotope content on the East Antarctic Plateau during glacial–interglacial transition and need to be improved in the future.

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Using beryllium-10 to test the validity of past accumulation rate reconstruction from water isotope records in East Antarctic ice cores

Climate of the Past Discussions ◽

10.5194/cpd-10-3421-2014 ◽

2014 ◽

Vol 10 (4) ◽

pp. 3421-3447

Author(s):

A. Cauquoin ◽

A. Landais ◽

G. M. Raisbeck ◽

J. Jouzel ◽

L. Bazin ◽

...

Keyword(s):

High Resolution ◽

Isotopic Composition ◽

Accumulation Rate ◽

Ice Core ◽

Ice Cores ◽

Temperature Reconstruction ◽

Atmospheric Composition ◽

Water Isotopes ◽

Polar Regions ◽

Water Distillation

Abstract. Ice cores are exceptional archives which allow us to reconstruct a wealth of climatic parameters as well as past atmospheric composition over the last 800 ka in Antarctica. Inferring the variations of past accumulation rate in polar regions is essential both for documenting past climate and for ice core chronology. On the East Antarctic plateau, the accumulation rate is so small that annual layers cannot be identified and accumulation rate is mainly deduced from the water isotopic composition assuming constant temporal relationships between temperature, water isotopic composition and accumulation rate. Such assumption leads to large uncertainties on the reconstructed past accumulation rate. Here, we use high resolution beryllium-10 (10Be) as an alternative tool for inferring past accumulation rate for the EPICA Dome C ice core, in East Antarctica. We present a high resolution 10Be record covering a full climatic cycle over the period 269 to 355 kyr BP from MIS 9 to MIS 10 (Marine Isotope Stages). After correcting 10Be for the estimated effect of the paleomagnetic field, we deduce that the classical estimation of accumulation rate variations from records of water isotopes agrees, with a possible underestimation of 16%, with the uncertainty on the temperature reconstruction from water isotopes in Antarctic ice cores. This is within their uncertainty of −10 to +30%. Finally, we show that the relationship between temperature and accumulation rate is comparable when using ice core data and results from several AGCM simulations run on glacial–interglacial conditions despite a larger spread in model outputs. These results indicate that the thermodynamic law linking moisture content in the air and temperature, as implemented in the different models, leads to realistic results even in polar regions, at the end of the water distillation trajectory.

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