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Evaluation of the sedimentation rate with 210Pb and 137Cs using the CRS model and estimation of the total inventory of sediment in the Algerian Coast
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Abdolkader Noureddine   |
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Abstract: (15657 Views) |
| Lead-210 and to a lesser extent 137Cs are the most widely used radionuclides in soil erosion and recent radiogeochronology studies. This is basically due to their appropriate half-life, suitable for studying sedimentary processes occurring in the last 100 – 150 years. In coastal systems, sediments are transported by rivers to the coastal ocean, deposited under the influence of several marine processes. A study was carried along the Algerian coast, between 1999 and 2004, under the framework of the IAEA regional project RAF/7/004. Sediment cores were collected from different stations as given in figure 1 on board of the research vessel of M.S. Benyahia of ISMAL in collaboration with COMENA and IAEA, in order to study sediment accumulation in this area. For this purpose, 210Pb and 137Cs were determined in sediment sections, using direct counting by gamma spectrometry analysis. The accuracy of their quantification is mainly dependent on the errors including ambient background variation, attenuation of the 210Pb 45 kev gamma ray in the sample and efficiency calibration. Vertical distribution of 210Pb and 137Cs in sediments cores were used as a tool to establish the sediment chronology and to estimate the total inventory in the coastal environment. Concentrations in Bq/kg dry weight of 210Pb and 137Cs were determined in the four sediment cores. For concentration levels of 137Cs it ranges from (1.3±0.1) Bq/Kg to (12.8±0.8) Bq/ Kg with an average value of 7.5 Bq/Kg, and for 210Pb concentrations in Bq/Kg dry weight it was found to be in the range of (57±5 to 895±98) Bq/Kg dry weight. The estimated sedimentation rates deduced from the 210Pb and 137Cs concentrations profiles (some of them are presented in figure 2) and using the CRS model [1], range from 20 mm/yr to 27 mm/yr. Sedimentation rates and total inventories were determined at each station and maximum peaks were identified. Data obtained in this work were compared to those carried out in the same area by other authors, [2], [3]. |
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| Keywords: Sedimentation rate, CRS model, 210Pb, 137Cs, Algerian Coast, Gamma Spectrometry |
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Full-Text [PDF 715 kb]
(3083 Downloads)
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Type of Study: Research/ Original/ Regular Article |
Received: 2012/01/11 | Revised: 2012/01/25 | Accepted: 2016/10/18 | ePublished: 2016/10/18
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