Double Reef, Guam 60 Year Coral Bomb-Produced Radiocarbon Data Andrews, A.H.; Asami, R.; Iryu, Y.; Kobayashi, D.R.; Camacho, F. Andrews, A.H. Asami, R. Iryu, Y. Kobayashi, D.R. Camacho, F. earth science/paleoclimate/corals and sclerosponges (sample identification,null,null,null,null,corals and sclerosponges,null,null,C,null) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,null,fraction of modern activity,null,corals and sclerosponges,raw,accelerator mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,null,per mil NBS oxalic acid,null,corals and sclerosponges,differenced,accelerator mass spectrometry,N,difference between A and B samples) earth science/paleoclimate/corals and sclerosponges (age,null,null,year Common Era,null,corals and sclerosponges,null,null,N,null) earth science/paleoclimate/corals and sclerosponges (delta 13C,Porites lobata,null,per mil VPDB,null,corals and sclerosponges,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,null,per mil NBS oxalic acid,null,corals and sclerosponges,corrected,accelerator mass spectrometry,N,t-corrected) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,one standard deviation,per mil NBS oxalic acid,null,corals and sclerosponges,raw,accelerator mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,one standard deviation,per mil NBS oxalic acid,null,corals and sclerosponges,null,accelerator mass spectrometry,N,null) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,null,per mil NBS oxalic acid,null,corals and sclerosponges,corrected,accelerator mass spectrometry,N,A sample t-corrected) earth science/paleoclimate/corals and sclerosponges (Delta 14C,Porites lobata,null,per mil NBS oxalic acid,null,corals and sclerosponges,corrected,accelerator mass spectrometry,N,B sample t-corrected) earth science/paleoclimate/corals and sclerosponges (Double Reef>LATITUDE 13.598183>LONGITUDE 144.83588) High-resolution radiocarbon (14C) analyses on a coral core extracted from Guam, a western tropical Pacific island, revealed a series of early bomb-produced 14C spikes. The typical marine bomb 14C signal-phase lagged and attenuated relative to atmospheric records-is present in the coral and is consistent with other regional coral records. However, 14C levels well above what can be attributed to air-sea diffusion alone punctuate this pattern. This anomaly was observed in other Indo-Pacific coral records, but the Guam record is unmatched in magnitude and temporal resolution. The Guam coral D14C record provided three spikes in 1954-55, 1956-57, and 1958-59 that are superimposed on a normal 14C record. Relative to mean pre-bomb levels, the first peak rises an incredible ~700permil and remained elevated for ~1.2 years. A follow up assay with finer resolution increased the peak by ~300permil. Subsequent spikes were less intense with a rise of ~35permil and ~70permil. Each can be linked to thermonuclear testing in the Pacific Proving Grounds at Bikini and Enewetak atolls in Operations Castle (1954), Redwing (1956), and Hardtack I (1958). These 14C signals can be explained by vaporization of coral reef material in the nuclear fireball, coupled with neutron activation of atmospheric nitrogen (14C production), and subsequent absorption of 14CO2 to form particulate carbonates of close-in fallout. The lag time in reaching Guam and other coral records abroad was tied to ocean surface currents and modeling provided validation of 14C arrival observations. STUDY NOTES: Carbon isotope (D14C) data for the past 60 years from a Porites lobata coral core (GD2) collected from Double Reef, Guam. Data are subsampled from original core from Asami et al. (2004, 2005) NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Andrews, A.H. Investigator : Asami, R. Investigator : Iryu, Y. Investigator : Kobayashi, D.R. Investigator : Camacho, F. 2016-07-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/20346 https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14cdup.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14c.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14chighres.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14cdup.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14c.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14chighres.txt English https://www.ncdc.noaa.gov/paleo/study/20346 https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14cdup.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14c.txt https://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14chighres.txt Andrews, A.H., R. Asami, Y. Iryu, D.R. Kobayashi, and F. Camacho2016Bomb-produced radiocarbon in the western tropical Pacific Ocean-Guam coral reveals operation-specific signals from the Pacific Proving GroundsJournal of Geophysical Research: Oceans12110.1002/2016JC012043 START YEAR: 1939 AD * END YEAR: 2000 AD 144.83588 13.598183 144.83588 13.598183