Sediment record linked to surface processes in the Cariaco Basin


  • Frank Muller-Karger,

    1. College of Marine Science, University of South Florida, St. Petersburg, Fla. 33701 USA
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  • Ramon Varela,

  • Robert Thunell,

  • Mary Scranton,

  • Richard Bohrer,

  • Gordon Taylor,

  • Juan Capelo,

  • Yrene Asto,

  • Eric Tappa,

  • Tung-Yuan Ho,

  • Maria Iabichella,

  • John J. Walsh,

  • Jose Rafael Diaz


The Cariaco Basin, off the northeast coast of Venezuela, has long been the center of attention of scientists trying to explain paleoclimate. This peculiar anoxic basin records climate change over several dozen millennia within layers of sediment [Black eta., 1999].

A joint U.S.-Venezuelan research effort launched in 1995—the Carbon Retention in a Colored Ocean (CARIACO) Program— provides a link between the sediment record and processes near the surface of the ocean for this basin. Sediment traps maintained by the program show that over 5% of the organic carbon contained in particles formed near the surface through primary production (photosynthesis) by phytoplankton reaches 275 m depth, and nearly 2% reaches 1,400 m.This flux is significant, because it represents a sink for carbon dioxide, which is a greenhouse gas, and because it helps explain the record of ancient climate stored at the bottom of the Cariaco Basin.