HR: 0830h
AN: OS31C-0218    [PDF]
TI: Temporal and Spatial Variations in the Oxygen Isotopic Compositions of Surface Waters from the Northern Caribbean
AU: * Swart, P
EM: pswart@rsmas.miami.edu
AF: MGG/RSMAS, 4600 Rickenbacker Causeway, Miami, Fl 33134 United States
AU: Saied, A
EM: asaied@rsmas.miami.edu
AF: MGG/RSMAS, 4600 Rickenbacker Causeway, Miami, Fl 33134 United States
AU: Schroeder, C
EM: cschroeder@rsmas.miami.edu
AF: MGG/RSMAS, 4600 Rickenbacker Causeway, Miami, Fl 33134 United States
AU: Williams, L
EM: liz@rsmas.miami.edu
AF: MPO/RSMAS, 4600 Rickenbacker Causeway, Miami, Fl 33149 United States
AB: Surface water samples collected over a nine-month period from a range of stations in the northern Caribbean and the Bahamas have been analyzed for their salinity vs. oxygen isotopic relationships. These samples were collected at approximate two week intervals during cruises made by the Royal Caribbean Explorer of the Seas. This vessel is equipped with a continuous flowing seawater system which can be used to sample water at predetermined locations. On alternate weeks the ship traced a track which during the first week included the Bahamas, Puerto Rico, and Virgin Islands, and the second week the Dominican Republic, Jamaica, the Cayman Islands, Cozomel, and Key West. As expected analyses show a positive correlation between salinity and the oxygen isotopic composition (m= 0.23), although the r value of only 0.55 suggest a variety of factors other than dilution with freshwater from a single source control the oxygen isotopic composition. These controls include evaporation as well as input of freshwaters with a range of oxygen isotopic compositions from different rivers and precipitation. Spatially the most positive oxygen isotopic values are found in the Bahamas, in the eastern portion of the cruise tract. These are enriched in oxygen-18 by 0.4 per mille compared to samples taken in the western portion at the same time. Temporally the isotopic composition are the most positive during the early portion of the year and trend towards more depleted values in the summer. Spatial differences tend to diminish in the summer months suggesting that the winter differences are related to variations in evaporation and summer values are more negative as a result of higher amounts of precipitation. The difference between winter and summer values is approximately 0.2 per mille. Further evaluation of the temporal and spatial relationship in this dataset will oxygen isotopic ratios in proxy indicators such as corals to be used in combination with temperature proxies as indicators of salinity.
UR: http://www.rsmas.miami.edu/rccl/
DE: 0330 Geochemical cycles
DE: 1045 Low-temperature geochemistry
DE: 1620 Climate dynamics (3309)
DE: 1655 Water cycles (1836)
DE: 1836 Hydrologic budget (1655)
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting