Radionuclide Limnochronology

Krishnaswami, S.; Lal, D.

doi:10.1007/978-1-4757-1152-3_6

Cited by 96 publications

(48 citation statements)

References 102 publications

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“…The results of the ~37Cs measurements of cores A and B are shown in figures 2a and 2b. The activity profiles of '37Cs correlate with its delivery pattern from the atmosphere [23], where the maximum activity corresponds to the year 1963. The 137Cs inventories in both cores are in very good agreement.…”

Section: Resultsmentioning

confidence: 85%

Sedimentation rates in the central lake constance determined with210Pb and137Cs

et al. 1987

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Sediment cores from central Lake Constance were dated with Zl~ and [37Cs. A sedimentation rate of(0.11 :t:0.02) g-cm-2.y -I was determined with the 21~ method. 137Cs measurements revealed sedimentation rates of (0.11+0.01) g.cm--~.y -t and (0.08:1:0.01) g.cm-2-y -I, respectively for two different cores sampled at the same location. The lower Cs-dated value indicates incomplete core recovery and demonstrates the sensitivity of this simple dating method to small losses of material at the water/sediment interface. An unambiguous application of the 137Cs method is, therefore, only possible if complete core recovery is ensured. Sedimentation rates based on particulate matter, collected in sediment traps at various water depths, agree with the results of the radioisotope methods. Estimates of 30-125 days residence times for suspended particulate matter were calculated from 7Be meausurements.

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Section: Resultsmentioning

confidence: 85%

Sedimentation rates in the central lake constance determined with210Pb and137Cs

et al. 1987

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“…Figure 1 shows the semi log plot of excess 210 Pb activity versus depth of core segment samples collected at Lambarpur side of the Bay. The slope of semi log plot was used for computation of sedimentation rate [10]. The sedimentation rate in all the cores was measured and was found 0.4 cm/y.…”

Section: Resultsmentioning

confidence: 99%

“…For example the fallout 137 Cs has been advantageously used by many researchers to quantify the soil erosion, estimating lake sediment age and in probing the transport. In addition to man made 137 Cs the naturally delivered radioisotopes like 210 Pb have been successfully used for lake and river sediment [10]. The unique property that makes radioisotopes invaluable in studying aquatic system is the inherent decay constant (yr −1 ) which governs the disintegration of the isotope with accurately known rate, which is independently of physical and chemical environment of isotopes.…”

Section: Introductionmentioning

confidence: 99%

Transport of pollutants from nearby catchments to the Nagarjuna Sagar Dam

et al. 2011

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Abstract. The understanding of the fate of the various pollutants and its mobility in the catchments of Nagarjun Sagar dam built on the Krishna river is of utmost important .As the Pedaguttu and Lambarpur catchments area has a proposed Uranium mining sites and Nagarjuna Sagar dam is the third largest man made dam which is the ultimate destination of all the rivulets in the Pedaguttu catchments. The concept of the distribution coefficient is invoked to understand the residence time of radionuclide on its nature. Expressions are derived to estimate the value of soil erosion constant using naturally occurring radionuclide. Based on 210 Pb profile in the sediment core, the sedimentary load of 0.24 gm m −2 y −1 was observed in the Pedaguttu and Lambarpur side of the Dam. The retention time and the transport coefficient of the pollutant were further obtained by using the appropriate modeling equation and was found 3776 and 2.7 × 10 −5 respectively. The comparative exercise of the retention time and transport coefficient was done with the other studied catchments of the world for the further validation of the result.

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“…There are two methods estimate the net sedimentation rates: (1) the mass balance method (Golterman, 1975) and (2) the sediment dating method (Krishnaswani and Lai, 1978). The mass balance method for total nitrogen and total phosphorus was applied to Box -1 (Fig.…”

Section: -3 Comparison Of Autochthonous Deposited Fluxes With Net Smentioning

confidence: 99%

Characteristics of autochthonous deposition and resuspension of sediments in the Takahamairi bay of Lake Kasumigaura.

1987

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There was a time lag of one or two months between the peak of primary production and that of autochthonous deposited flux, which resulted in a surprising increase in chlorophyll a concentration of lake water in mid-summer. Calculated autochthonous deposited rates of carbon, nitrogen, and phosphorus in backwater regions and near the inflow river mouth were much higher than those at offshore due to the contamination of allochthonous matter . In regard to the resuspension rates, a logarithmic decrease against water depth and significant correlations with some meteorological conditions were observed. The sum of autochthonous and allochthonous deposited fluxes exceeded the accumulation rates in sediments estimated both by the mass balance method and the sediment dating method by a factor of 8-17 for nitrogen and 2-10 for phosphorus, both of which were much larger than the ratios observed in other lakes.The shallowness of this lake greatly influenced these ratios because of the large resuspension rate followed by rapid decomposition in lake water and high activity of benthos .

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Radionuclide Limnochronology

Cited by 96 publications

References 102 publications

Sedimentation rates in the central lake constance determined with210Pb and137Cs

Sedimentation rates in the central lake constance determined with210Pb and137Cs

Transport of pollutants from nearby catchments to the Nagarjuna Sagar Dam

Characteristics of autochthonous deposition and resuspension of sediments in the Takahamairi bay of Lake Kasumigaura.

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