HR: 1340h
AN: OS13B-0537    [Abstracts]
TI: Radiocarbon in Surface Waters of the Gulf of Mexico and Caribbean as Recorded in Hermatypic Corals
AU: * Bratcher, A J
EM: amyb@ocean.tamu.edu
AF: Department of Oceanography, Texas A&M University, College Station, TX 77843-3146 United States
AU: Guilderson, T P
EM: tguilderson@llnl.gov
AF: Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 United States
AU: Slowey, N C
EM: slowey@ocean.tamu.edu
AF: Department of Oceanography, Texas A&M University, College Station, TX 77843-3146 United States
AU: Cole, J E
EM: jcole@geo.arizona.edu
AF: Department of Geosciences, University of Arizona, Tucson, AZ 85721 United States
AB: Radiocarbon measurements of hermatypic corals from near the Cariaco Basin and Veracruz, Mexico are used to reconstruct the D14C of surface waters in the Caribbean Sea and western Gulf of Mexico. These results will be used to investigate the carbon flux from the atmosphere into the ocean in these regions. Coral chronology was resolved using x-radiography to determine annual density bands deposited during the warm summer months. Sub-annual and annual samples were obtained from 1943-1996 using a microdrill and radiocarbon composition was determined using accelerator mass spectrometry. The corals were sampled at annual intervals from 1945-1955 and average values from the two sites are similar (-52 $\pm$4 per mil at Veracruz and -53 $\pm$3 per mil at Cariaco). Due to the production of 14C as a consequence of nuclear weapons atmospheric tests in the 1950s and 1960s, the D14C in the coral skeletal material began increasing in the late 1950s and reached a maximum in 1978 of 165 $\pm$4 per mil at Veracruz and 127 $\pm$3 per mil in 1973 at Cariaco Basin. These data and additional radiocarbon measurements of corals from the Flower Garden Banks (northern Gulf of Mexico) and published data from the region will be used to investigate the processes controlling radiocarbon concentrations in the surface waters of the Caribbean Sea and Gulf of Mexico.
DE: 4806 Carbon cycling
DE: 4504 Air/sea interactions (0312)
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting