Radiocarbon Measurements on Samples of Known Age

Broecker, Wallace S.; Olson, Edwin A.; Bird, Junius B.

doi:10.1038/1831582a0

Cited by 24 publications

(9 citation statements)

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“…However, several other investigators used different tree-ring sequences to determine their sample ages. They at least qualitatively confirmed de Vries' results (Broecker, Olson & Bird, 1959;Willis, Tauber & Munnich, 1960;Ralph, 1959). As the cause of the 14C variations, these investigators considered changes in the 14C production rate through modulation of the cosmic ray flux by solar activity (see also Suess, 1958Suess, , 1968.…”

Section: The De Vries Variationssupporting

confidence: 66%

Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation

Sueß

1986

Radiocarbon

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ABSTRACT. Measurement of 14C in samples of wood of precisely known age have shown that the cosmogenic 14C content of the CO2 in the atmosphere has not remained constant during the period of time covered by radiocarbon dating. As the terrestrial atmosphere mixes with a time constant of less than 3 years, these variations must be essentially independent of geographic location. The 14C in atmospheric CO2 must be a quantity that, at a given time, pertains to the terrestrial atmosphere as a whole. Not only is its knowledge necessary for deriving accurate radiocarbon dates, but it is also valuable in connection with many geophysical and astrophysical problems. Unfortunately, progress in our knowledge of 14C variations in the terrestrial atmosphere has been delayed by hidden experimental errors in results obtained by many laboratories. By rigorous statistical analysis of the La Jolla results, it is now possible to show that the 14C variations are not simple random fluctuations but show distinct regularities. Similar patterns of variations have been found in the growth rate of trees during the last 5000 years. Measurements of radiogenic 10Be currently being done by European workers promise to conclusively elucidate the 14C findings. THE DE VRIES VARIATIONSWillard F Libby, at the time when he and his co-workers published the first results of radiocarbon measurements around 1950(Libby, 1952, believed that the exchange of the carbon dioxide in the atmosphere with the bicarbonate of the oceans occurred quickly compared to all other changes in the ocean-atmosphere system. He, therefore, assumed that ocean and atmosphere can be considered as one and the same large carbon reservoir, reacting, as Libby put it, to changes in the 14C production rate "only extremely sluggishly." Libby considered variations such as those observed by H de Vries (1958) in the 14C content of wood from the 15th and 17th centuries AD to be within the experimental error of the measurements. However, I had been able to show (Suess, 1953) that the exchange rate of carbon dioxide between atmosphere and ocean was not sufficiently fast to exclude the possibility of variations of a few per cent, as indicated by the measurements of de Vries. In order to explain the results obtained by de Vries, Libby had also suggested the consideration of possible errors in the dendrochronologic dating that de Vries (pers commun, 1954) had used for his measurements. However, several other investigators used different tree-ring sequences to determine their sample ages. They at least qualitatively confirmed de Vries' results (Broecker, Olson & Bird, 1959;Willis, Tauber & Munnich, 1960;Ralph, 1959). As the cause of the 14C variations, these investigators considered changes in the 14C production rate through modulation of the cosmic ray flux by solar activity (see also Suess, 1958Suess, , 1968. This matter has been discussed from a more quantitative viewpoint by Stuiver (1961) and by Stuiver and Quay (1980 (Suess, 1970). This curve reached back to 5400 BC, as far back in tim...

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Section: The De Vries Variationssupporting

confidence: 66%

Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation

Sueß

1986

Radiocarbon

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“…Baxter and Walton (1971) reported an 30%° A14C variation from 1890-1950, and later, Baxter and Farmer (1973) reported a 10 to 20%° variation from 1829-1865, both with an 11-year periodicity, anti-correlated with sunspot numbers. But the A14C values in tree-ring samples from the same period measured by others (Broecker, Olson, and Bird, 1959;Cowan, Atluri, and Libby, 1965;Suess, 1965;Lerman, Mook, and Vogel, 1967;Damon, Long, and Wallick, 1973a;Tans, DeJong, and Mook, 1979;Burchuladze et al:, 1980;Stuiver andQuay, 1980, 1981) do not show any large amplitude fluctuations, although some of them also exhibit 11-year periodicity. Since Baxter and Walton used grains grown in Scotland at latitudes 54°N, higher than that of most other sample locations, the disagreement may be due to Department of Physics, University of Arizona, Tucson *Radiocarbon Laboratory, Archaeological Section, History Department, Peking University, Beijing, China Department of Physics, Nanjing University, Nanjing, China the difference in latitudes as well as in the time and duration of photosynthetic assimilation of CO2 by plants (Baxter and Farmer, 1973).…”

Section: Introductionmentioning

confidence: 63%

Radiocarbon Activity Variation in Dated Tree Rings Grown in Mackenzie Delta

et al. 1983

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Forty-five tree rings (1881–1925) were taken from a white spruce grown near Campbell River in Mackenzie Delta, Canada, for the measurement of 14C activity variation. Because of the narrowness of the rings, 2 and sometimes 3 rings were combined to yield a total of 21 specimens. The 14C content in these specimens was measured with a liquid scintillation-PM tube counter system of the History Department of Peking University. The data points exhibit a 10‰ variation, anti-correlated with sunspot numbers. The physical implication is discussed.

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“…Radiocarbon dates began to indicate the possibility that an earlier correlation might be more accurate. Measurements published in 1951, 1955, and 1959(Kulp, Feely, and Tryon 1951Libby 1955;Broecker, Olson, and Bird 1959) appeared as strong support of the Spinden correlation (12.9.0.0.0). In October 1960 (Satterthwaite and Ralph 1960) however, an impressive analysis of a number of samples from Tikal by Elizabeth Ralph corrects the figures and indicates that probably the Goodman-Martinez-Thompson correlation is closest to the true value.…”

mentioning

confidence: 71%

A Quarter Century of Growth in American Archaeology

Johnson

1961

Am. antiq.

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To introduce papers presented at a celebration of the 25th annual meeting of The Society for American Archaeology the development of New World archaeology is very broadly and briefly summarized. Expanding knowledge of culture areas and taxonomic systems is traced. The development of salvage archaeology in reservoir areas, along roads and oil pipelines is mentioned. There is an account of the development of various types of relative chronologies in the several areas and comment upon the significance of the introduction of radiocarbon dates. Special mention is made of the possible solution of the question of correlating Mayan and Julian calendars.

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Radiocarbon Measurements on Samples of Known Age

Cited by 24 publications

References 9 publications

Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation

Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation

Radiocarbon Activity Variation in Dated Tree Rings Grown in Mackenzie Delta

A Quarter Century of Growth in American Archaeology

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Radiocarbon Measurements on Samples of Known Age

Cited by 24 publications

References 9 publications

Secular Variations of Cosmogenic 14C on Earth: Their Discovery and Interpretation

Secular Variations of Cosmogenic 14C on Earth: Their Discovery and Interpretation

Radiocarbon Activity Variation in Dated Tree Rings Grown in Mackenzie Delta

A Quarter Century of Growth in American Archaeology

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Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation

Secular Variations of Cosmogenic ¹⁴C on Earth: Their Discovery and Interpretation