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  • 1
    Electronic Resource
    Electronic Resource
    Time dependence of organic matter decay and mixing processes in Framvaren, a permanently anoxic fjord in South Norway (1996)
    Springer
    Aquatic geochemistry 2 (1996), S. 111-129 
    Details
    ISSN: 1573-1421
    Keywords: Framvaren fjord ; anoxic waters ; sulfide ; tritium ; silica ; mineralization and ventilation rates ; carbon isotopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Three different layers have been identified in Framvaren, which has a maximum water depth of 184 m. One oxic layer above the redoxcline at 18–20 m. One anoxic layer from 20 to 100 m which is occasionally ventilated by a flow over the sill (which has a depth of 2.5 m), and finally a stagnant layer below 100 m. Using the release rate of silica from the bottom and measurements of the concentration of HTO it is possible to make some calculations on the annual volume of interleaving in the layers 25–50 m, 50–75 m, and 75–100 m together with the advective flows. Reliable values of the sulfide concentration were obtained by precipitating and weighing HgS together with careful protection of all anoxic water samples with argon. The light yellow color of the precipitate in the depth range 25 to 80 m indicates that the occasional ventilation will cause such reactions as 0.502 + H2S S(colloidal) + H2O. The elemental sulfur, being stabilized with HS−, is set free upon the precipitation of HgS. The new data for the concentration of sulfide give an acceptable stoichiometry for the decay reaction of organic matter. This is not the case with the data of Yao and Millero. The mean values for the concentrations of ammonium and phosphate agree with the new data of Yao and Millero. The mol/mol C/N ratio of 10.1 found in trapped material by Naess and coworkers (1988) agrees with the stoichiometry of the dissolved constituents, i.e. C/N = 9.92 ± 0.45. A denitrification reaction is suggested to explain the high values of C/N. The vertical diffusion coefficient at 100 m calculated from the depth profile of silica was 0.92 × 10−6 m2 s−1 which lies in the range of values given by Fröyland. Finally, the 14C age of the total dissolved inorganic carbon (Ct) in the water below 90 m was about 1600 years indicating a bioproduction in the period 8000 years B.P. to A.D. 1853 when a channel was opened between the fjord outside (Helvikfjord) and Framvaren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00121627
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  • 2
    Electronic Resource
    Electronic Resource
    Framvaren and the Black Sea – Similarities and Differences (1999)
    Springer
    Aquatic geochemistry 5 (1999), S. 59-73 
    Details
    ISSN: 1573-1421
    Keywords: Framvaren fjord ; Black Sea ; carbon isotopes ; tritium ; alkalinity ; total carbonate ; sulfide ; molybdenum ; denitrification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The following determinations in the Norwegian fjord Framvaren and the Black Sea have been compared: carbon-14, carbon-13, alkalinity, total dissolved inorganic carbon, sulfide, tritium (HTO), trace metals, silica, ammonium and phosphate. The historical development of the two anoxic basins is quite different. The carbon-14 age of the total inorganic dissolved carbonate in the deep water is 2000 years in the Black Sea, but only 1600 in Framvaren. The fresh water supply and composition are different. The rivers entering the Black Sea have a high alkalinity, but the river input and runoff to Framvaren has a very low alkalinity. The alkalinity, carbonate and sulfide concentrations in the anoxic waters below the chemoclines are much higher in Framvaren. This is mainly an effect of the different surface to volume ratios. The difference in carbon-13 (-8‰ for the Black Sea deep water, -19‰ in the Framvaren bottom water) is mainly due to the smaller imprint of the decomposition of organic matter on the Black Sea deep water. The concentration of trace metals in the particulate form are about the same in the deep water. About 76% of the molybdate in seawater is lost in the sulfidic water of Framvaren, and about 82–96% of the molybdate carried into the Black Sea by the Bosporus undercurrent is lost in the deep water. The relation between silica, ammonium and phosphate can be understood if part of the ammonium is being removed by denitrification, a process that most likely has been going on for thousands of years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009663704604
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  • 3
    Electronic Resource
    Electronic Resource
    The Source of Silica and Trace Metals in Particulate Matter in Framvaren Fjord (1997)
    Springer
    Aquatic geochemistry 3 (1997), S. 329-343 
    Details
    ISSN: 1573-1421
    Keywords: Framvaren ; Farsundite ; watershed ; runoff ; silica ; aluminium ; trace metals ; sulfides ; particulate matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The lake and streams in the Framvarenwatershed were sampled and analyzed in September 1983.The results can be explained by the precipitation ofacid rain containing some sea salts and thedissolution of Farsundite, the dominating rock in thecatchment area. The runoff supplies the surface waterof Framvaren with silica, aluminium, manganese, iron,copper, zinc, cadmium and lead. Reasonablecalculations show that the runoff most likely is themain source for the particulate matter found insediment traps and by filtering off suspendedparticles. Thus the calculations supplement recentstudies of Skei et al. (1996).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009629620297
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