• Radiocarbon, Volume 27, Number 3 (1985)

      American Journal of Science, 1985-01-01
    • The Effect of Atmospheric 14C Variations on the 14C Levels in the Jordan River System

      Carmi, Israel; Stiller, M.; Kaufman, Aaron (American Journal of Science, 1985-01-01)
      13C and 14C were measured in the upper Jordan River, in its tributaries which issue from the Mount Hermon aquifer, and in the local atmospheric CO2 to evaluate the degree to which changes in the atmospheric 14C levels influence the 14C levels in the aquifer and in the Jordan River. The exchange fraction of CO2 between the river and the atmosphere was calculated for fall 1983 with the two carbon isotopes and it is shown that the value obtained with 14C (0.364) is the more reliable. The ratio of 14C in the Jordan River to that in the atmosphere in 1972 is similar to that in 1983, 0.66 and 0.67, respectively. This implies an approximately constant ratio (0.44) between the 14C level in the Mount Hermon aquifer baseflow and the 14C level in the atmospheric CO2. This information can be combined with the known historical fluctuations in the 14C levels of the atmosphere to calculate the 14C fluctuations in the discharge of the Jordan River into Lake Kinneret, backwards in time.
    • Vienna Radium Institute Radiocarbon Dates XV

      Felber, Heinz (American Journal of Science, 1985-01-01)
    • Radiocarbon, Volume 27, Number 2A (1985)

      American Journal of Science, 1985-01-01
    • Radiocarbon, Volume 27, Number 1 (1985)

      American Journal of Science, 1985-01-01
    • Radiocarbon, Volume 27, Number 2B (1985)

      American Journal of Science, 1985-01-01
    • Gliwice Radiocarbon Dates X

      Pazdur, Mieczysław F.; Awsiuk, Romuald; Bluszcz, Andrzej; Goslar, Tomasz; Pazdur, Anna; Walanus, Adam; Zastawny, Andrezej (American Journal of Science, 1985-01-01)
    • British Museum Natural Radiocarbon Measurements XVIII

      Ambers, Janet; Matthews, Keith; Burleigh, Richard (American Journal of Science, 1985-01-01)
    • 25 Years of Trospheric 14C Observations

      Ingeborg Levin; Kromer, Bernd; Schoch-Fischer, Hildegard; Michael Bruns; Münnich, Marianne; Berdau, Dietrich; Vogel, John C.; Münnich, Karl Otto (American Journal of Science, 1985-01-01)
      A long-term mountain station series of tropospheric 14C data for the period 1959 to 1984 is presented. This series is considered representative of the higher altitude 14C level over central Europe. Even tree-ring 14C levels from a rural ground level site in southern Germany are consistently lower (by Delta-14C depression = -15 per mil if compared with the mountain station summer average in atmospheric CO2). The rural tree-ring series is considered to represent the additional continental Suess effect at ground level without local contamination. This Suess effect decreases gradually with the distance from the ground (ie, source) level. We therefore estimate the additional continental Suess effect in the vegetation period to be Delta-14C depression = -5 per mil for the mountain station and -20 per mil for a rural ground level site, respectively. Based on this assumption, yearly mean tropospheric 14C levels corrected for fossil fuel contamination and representative of the Northern Hemisphere are provided for use in global carbon cycle models.
    • Contamination Studies on Mollusk Shell Samples

      Goslar, Tomasz; Pazdur, Mieczysław F. (American Journal of Science, 1985-01-01)
      A series of shell samples has been studied to determine the magnitude and mechanisms of carbon exchange between shells and their environment. Laboratory contamination experiments included the storing of shell samples in acid and calcareous environments of different 14C concentrations as well as studies of carbon exchange in the course of thermal recrystallization in solid state in an atomosphere of carbon dioxide. The applicability of differential thermal analysis to studies of the structure and texture of shells is discussed.
    • Harwell Radiocarbon Measurements IV

      Walker, A. J.; Otlet, R. L. (American Journal of Science, 1985-01-01)
    • University College Cardiff Radiocarbon Dates I

      Dresser, Quentin (American Journal of Science, 1985-01-01)
    • Index

      American Journal of Science, 1985-01-01
    • INGEIS Radiocarbon Laboratory Dates II

      Albero, Miguel C.; Angiolini, Fernando E. (American Journal of Science, 1985-01-01)
    • Trondheim Natural Radiocarbon Measurements IX

      Nydal, Reidar; Gulliksen, Steinar; Lövseth, Knut; Skogseth, Fred (American Journal of Science, 1985-01-01)
    • Historical 14C Measurements from the Atlantic, Pacific and Indian Oceans

      Fairhall, A. W.; Young, A. W. (American Journal of Science, 1985-01-01)
    • Physical Research Laboratory Radiocarbon Date List V

      Agrawal, D. P.; Krishnamurthy, R. V.; Kusumgar, Sheela (American Journal of Science, 1985-01-01)
    • Amplitude of Sunspot-Dependent Radiocarbon Variations: Data from Corals and Wine

      Magaritz, Mordeckai; Carmi, Israel; Sirkes, Ziv (American Journal of Science, 1985-01-01)
    • Lyon Natural Radiocarbon Measurements X

      Evin, Jacques; Marechal, Joelle; Marien, Gerard (American Journal of Science, 1985-01-01)