# Double Reef, Guam 60 Year Coral Bomb-Produced Radiocarbon Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 2.0 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/20346 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/coral/west_pacific/guam2016d14cdup.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Corals and Sclerosponges # # Parameter_Keywords: carbon isotopes #-------------------- # Contribution_Date # Date: 2016-07-18 #-------------------- # Title # Study_Name: Double Reef, Guam 60 Year Coral Bomb-Produced Radiocarbon Data #-------------------- # Investigators # Investigators: Andrews, A.H.; Asami, R.; Iryu, Y.; Kobayashi, D.R.; Camacho, F. #-------------------- # Description_and_Notes # Description: 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) # # Provided Keywords: Carbon-14, environmental radioactivity, fallout, thermonuclear bomb, bomb radiocarbon #-------------------- # Publication # Authors: Andrews, Allen H.; Asami, Ryuji; Iryu, Yasufumi; Kobayashi, Donald R.; Camacho, Frank # Published_Date_or_Year: submitted 2016 # Published_Title: Bomb-produced radiocarbon in the western tropical Pacific Ocean-Guam coral reveals operation-specific signals from the Pacific Proving Grounds # Journal_Name: Journal of Geophysical Research - Oceans # Volume: # Edition: # Issue: # Pages: # Report_Number: # DOI: # Online_Resource: # Full_Citation: # Abstract: 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. #------------------ # Funding_Agency # Funding_Agency_Name: US NOAA National Marine Fisheries Service Saltonstall Kennedy program # Grant: NA14NMF4270056 #------------------ # Site_Information # Site_Name: Double Reef # Location: Ocean>Pacific Ocean>Central Pacific Ocean>Guam # Country: United States Of America # Northernmost_Latitude: 13.598183 # Southernmost_Latitude: 13.598183 # Easternmost_Longitude: 144.83588 # Westernmost_Longitude: 144.83588 # Elevation: -4.5 m #------------------ # Data_Collection # Collection_Name: GD2D14Cdup # Earliest_Year: 1998 # Most_Recent_Year: 2000 # Time_Unit: AD # Core_Length: m # Notes: #------------------ # Chronology_Information # Chronology: # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ## ID Sample ID,,,,,,,,C ## age_AD age, , , AD, , , , ,N ## D14Ccorr Delta14C corrected, calcium carbonate, , per mil, ,coral, , A sample t-corrected,N ## D14Cerr Delta14C error, calcium carbonate, , per mil, ,coral, , ,N ## D14CcorrB Delta14C corrected B sample, calcium carbonate, , per mil, ,coral, , B sample t-corrected,N ## D14Cdif Delta14C difference, calcium carbonate, , per mil, ,coral, , difference between A and B samples,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # # Appendix III - A replicate sample series (parenthetical numbers) was performed to test elevated values, but revealed there was contamination # near actively growing region of the coral. Deviations from expected trend on the order of 10 per mil (> 2 SD) were eliminated from further # consideration. Both GD2-004 samples were deemed contaminated and removed from the analysis. # ID age_AD D14Ccorr D14Cerr D14CcorrB D14Cdif GD2-001 2000.091 84.11 2.5 GD2-001B 2000.091 3.7 82.42 1.69 GD2-002 1999.910 86.02 3.3 GD2-002B 1999.910 2.8 76.58 9.44 GD2-003 1999.730 83.46 2.6 GD2-003B 1999.730 3.5 83.26 0.20 GD2-004 1999.545 97.20 3.3 GD2-004B 1999.545 3.1 95.51 1.69 GD2-005 1999.364 85.40 2.5 GD2-005B 1999.364 2.8 82.91 2.49 GD2-006 1999.182 98.25 2.5 GD2-006B 1999.182 2.7 86.91 11.33 GD2-007 1999.000 96.88 3.1 GD2-007B 1999.000 2.8 86.84 10.04 GD2-008 1998.819 96.61 2.5 GD2-008B 1998.819 2.6 85.17 11.43 GD2-009 1998.639 83.71 2 GD2-009B 1998.639 2.2 86.09 -2.39 GD2-010 1998.455 81.24 2 GD2-010B 1998.455 2.3 86.61 -5.37