Showing papers by "Richard G. Fairbanks published in 1993"
TL;DR: This article used thermal ionization mass spectrometry (TIMS) to obtain precise U-Th ages and to compare them with the 14C estimates measured on the same samples.
Abstract: In 1988, Fairbanks conducted a drilling expedition off the south coast of Barbados to recover submerged corals contemporaneous with the last deglaciation. Core recovery was excellent and >30 different samples were dated by conventional β-counting techniques (Fairbanks 1989). At about the same time, we developed, at Lamont, the thermal ionization mass spectrometry (TIMS) technique to obtain precise U-Th ages (Edwards 1988), and to compare them with the 14C estimates measured on the same samples. A surprising result was that the discrepancy between 14C and U-Th ages increased through time to ca. 3000–3500 yr at ca. 15,000 14C BP (Bard et al. 1990a). Because the three youngest samples yielded U-Th ages in agreement with their calibrated 14C ages, we concluded initially that the TIMS U-Th determinations were not only precise, but also accurate, and that the 14C vs. U-Th data set could be used for a first-order 14C calibration.
426 citations
TL;DR: Spectral analysis suggests that the distribution of variance in this record has shifted among annual to interannual periods during the present century, concurrent with observed changes in the strength of the Southern Oscillation.
Abstract: In the western tropical Pacific, the interannual migration of the Indonesian Low convective system causes changes in rainfall that dominate the regional signature of the El Nino—Southern Oscillation (ENSO) system. A 96-year oxygen isotope record from a Tarawa Atoll coral (1°N, 172°E) reflects regional convective activity through rainfall-induced salinity changes. This monthly resolution record spans twice the length of the local climatological record and provides a history of ENSO variability comparable in quality with those derived from instrumental climate data. Comparison of this coral record with a historical chronology of EI Nino events indicates that climate anomalies in coastal South America are occasionally decoupled from Pacific-wide ENSO extremes. Spectral analysis suggests that the distribution of variance in this record has shifted among annual to interannual periods during the present century, concurrent with observed changes in the strength of the Southern Oscillation.
337 citations
TL;DR: In this paper, it was shown that changes in air-sea exchange processes are a significant source of variability for any marine δ13C signal, and that this thermodynamic influence varies between water masses with a magnitude which is large relative to the amplitude of typical deep sea sediment δ 13C records.
Abstract: Air-sea exchange represents an important controlling factor for the distribution of carbon isotopes in the modern ocean, even below the surface mixed layer. Here we show that this thermodynamic influence varies between water masses with a magnitude which is large relative to the amplitude of typical deep sea sediment δ13C records. Thus, changes in air-sea exchange processes must be regarded as a significant source of variability for any marine δ13C signal.
118 citations
4 citations